[Retracted] Exosome-mediated transfer of lncRNA­SNHG14 promotes trastuzumab chemoresistance in breast cancer.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the TUNEL assay data shown in Fig. 6C were strikingly similar to images that had already appeared in Fig. 8B in another article that appeared in the journal Oncotarget [Chen W, Xu X-K, Li J-L, Kong K-K, Li H, Chen C, He J, Wang F, Li P, Ge X-S and Li F-C: MALAT1 is a prognostic factor in glioblastoma multiforme and induces chemoresistance to temozolomide through suppressing miR-203 and promoting thymidylate synthase expression. Oncotarget 8: 22783-22799, 2017]. Owing to the fact that the contentious data in the above article had already been published elsewhere prior to its submission to International Journal of Oncology, the Editor has decided that this paper should be retracted from the Journal on account of a lack of confidence in the presented data. The authors did provide an explanation to account for the duplication of the data, although this was not accepted by the Editorial Board. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Oncology 53: 1013-1026, 2018; DOI: 10.3892/ijo.2018.4467].

HuR confers IL-17a-induced migration and invasion of gastric cancer cells via upregulation of Snail translation.

Human gastric cancer is a leading cause of cancer mortality in the world wide. We found that the expression of IL-17a was significantly increased in gastric cancer cells. Treatment with recombinant IL-17a (rIL-17a) can increase migration, invasion and epithelial to mesenchymal transition (EMT) of gastric cancer cells. Further, Snail, a key factor to regulate EMT, was significantly increased in rIL-17a-treated gastric cancer cells. While knockdown of Snail can abolish IL-17a-induced EMT of gastric cancer cells. Mechanistically, IL-17a can promote the translation efficiency of Snail, while had no effect on its mRNA expression or protein stability. Further, we found that IL-17a can increase the expression of HuR, which markedly promoted translation of Snail mRNA. While knockdown of HuR can reverse rIL-17a-induced expression of Snail and EMT of gastric cancer cells. Collectively, our data suggested that HuR confers IL-17a induced migration and invasion of gastric cancer cells via upregulation of Snail translation.

Circular RNA Fibroblast Growth Factor Receptor 1 Promotes Pancreatic Cancer Progression by Targeting MicroRNA-532-3p/PIK3CB Axis.

OBJECTIVE: The aim of the study is to explore the contribution and mechanism of circular RNA fibroblast growth factor receptor 1 (circFGFR1) in pancreatic ductal adenocarcinoma (PDAC) progression. METHODS: Expressions of circFGFR1, microRNA (miR)-532-3p, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta (PIK3CB) were assessed by quantitative real-time polymerase chain reaction or in situ hybridization. Fluorescence in situ hybridization determined the subcellular localization of circFGFR1. Immunohistochemistry was used to detect PIK3CB expression in PDAC tissues. Cell growth was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays. Wound healing, transwell, and flow cytometry assays examined the migration, invasion, and apoptosis. Dual-luciferase and RNA pull-down assay verified the interactions between circFGFR1/PIK3CB and miR-532-3p. In vivo xenograft tumor growth and lung metastasis were assessed in nude mice. RESULTS: Functionally, knockdown of circFGFR1 restrained in vitro PDAC cell growth, migration, invasion, and in vivo xenograft tumor growth and lung metastasis. In addition, circFGFR1 could sponge miR-532-3p to upregulate PIK3CB level. Rescue experiments revealed that the tumor-suppressive effects caused by miR-532-3p mimics could be reversed by circFGFR1 or PIK3CB overexpression. CONCLUSIONS: Our data revealed that circFGFR1 driven the malignant progression of PDAC by targeting miR-532-3p/PIK3CB axis, suggesting that inhibition of circFGFR1 might be considered as a therapeutic target for PDAC.

Exosome-transmitted miR-567 reverses trastuzumab resistance by inhibiting ATG5 in breast cancer.

Trastuzumab is commonly used in the treatment of human epidermal growth factor receptor-2 positive (HER-2+) breast cancer, but its efficacy is often limited by the emergence of chemoresistance. Recent studies indicate that exosomes act as vehicles for exchange of genetic cargo between heterogeneous populations of tumor cells, engendering a transmitted drug resistance for cancer development and progression. However, the specific contribution of breast cancer-derived exosomes is poorly understood. In this study, publicly available expression profiling data from breast cancer and bioinformatics analyses were used to screen potential miRNAs in trastuzumab resistance. A series of gain- or loss-functional assays were performed to define the function of miR-567 and ATG5 in trastuzumab resistance and autophagy, both in vitro and in vivo. Our results showed that miR-567 was significantly decreased in trastuzumab-resistant patients compared with responding patients. Moreover, miR-567 was also downregulated in trastuzumab-resistant cells compared with parental cells. Overexpression of miR-567 reversed chemoresistance, whereas silence of miR-567 induced trastuzumab resistance, both in vitro and in vivo. In addition, enhanced miR-567 could be packaged into exosomes, incorporated into receipt cells, suppressing autophagy and reversed chemoresistance by targeting ATG5. To conclude, exosomal miR-567 plays a key role in reversing trastuzumab resistance via regulating autophagy, indicating it may be a promising therapeutic target and prognostic indicator for breast cancer patients.

Activation of LncRNA TINCR by H3K27 acetylation promotes Trastuzumab resistance and epithelial-mesenchymal transition by targeting MicroRNA-125b in breast Cancer.

BACKGROUND: Trastuzumab resistance followed by metastasis is a major obstacle for improving the clinical outcome of patients with advanced human epidermal growth factor receptor 2-positive (HER-2+) breast cancer. While long non-coding RNAs (lncRNAs) can modulate cell behavior, the contribution of these RNAs in trastuzumab resistance and metastasis of HER-2+ breast cancer is not well known. In this study, we sought to identify the regulatory role of lncRNA in trastuzumab resistance and accompanied Epithelial-mesenchymal Transition (EMT) process in advanced HER-2+ breast cancer. METHODS: Trastuzumab-resistant SKBR-3-TR and BT474-TR cell lines were established by grafting SKBR-3 and BT474 cells into mouse models and subjected to trastuzumab treatment. LncRNA microarray followed by quantitative reverse transcription PCR (qRT-PCR) was carried out to verify the differentially expressed lncRNAs. Western blotting, bioinformatics analysis, immunofluorescence assay and immunoprecipitation assays (ChIP and RIP) were performed to identify the involvement and functional interactions between H3K27 acetylation and terminal differentiation-induced non-coding RNA (TINCR) or between TINCR and its downstream genes including miR-125b, HER-2 and Snail-1. In addition, a series of in vitro and in vivo assays were performed to assess the functions of TINCR. RESULTS: An increase in both, IC50 value of trastuzumab and EMT was observed in the established trastuzumab-resistant cell lines. The expression level of TINCR was significantly increased in trastuzumab-resistant cells when compared with sensitive cells. Knockdown of TINCR reversed the trastuzumab resistance and the acquired EMT in these cells. TINCR was detected in the cytoplasm of breast cancer cells and could sponge miR-125b, thereby releasing HER-2 and inducing trastuzumab resistance. In addition, Snail-1 was found to be the target gene of miR-125b and overexpression of Snail-1 could reverse the suppressed migration, invasion, and EMT caused by TINCR silencing. The upregulation of TINCR in breast cancer was attributed to the CREB-binding protein (CBP)-mediated H3K27 acetylation at the promoter region of TINCR. Clinically, HER-2+ breast cancer patients with high TINCR expression levels were associated with poor response to trastuzumab therapy and shorter survival time. CONCLUSION: TINCR could promote trastuzumab resistance and the accompanied EMT process in breast cancer. Therefore, TINCR might be a potential indicator for prognosis and a therapeutic target to enhance the clinical efficacy of trastuzumab treatment.

Long non-coding RNA SNHG14 induces trastuzumab resistance of breast cancer via regulating PABPC1 expression through H3K27 acetylation.

Currently, resistance to trastuzumab, a human epidermal growth factor receptor 2 (HER2) inhibitor, has become one major obstacle for improving the clinical outcome of patients with advanced HER2+ breast cancer. While cell behaviour can be modulated by long non-coding RNAs (lncRNAs), the contributions of lncRNAs in progression and trastuzumab resistance of breast cancer are largely unknown. To this end, the involvement and regulatory functions of lncRNA SNHG14 in human breast cancer were investigated. RT-qPCR assay showed that SNHG14 was up-regulated in breast cancer tissues and associated with trastuzumab response. Gain- and loss-of-function experiments revealed that overexpression of SNHG14 promotes cell proliferation, invasion and trastuzumab resistance, whereas knockdown of SNHG14 showed an opposite effect. PABPC1 gene was identified as a downstream target of SNHG14, and PABPC1 mediates the SNHG14-induced oncogenic effects. More importantly, ChIP assays demonstrated that lncRNA SNHG14 may induce PABPC1 expression through modulating H3K27 acetylation in the promoter of PABPC1 gene, thus resulting in the activation of Nrf2 signalling pathway. These data suggest that lncRNA SNHG14 promotes breast cancer tumorigenesis and trastuzumab resistance through regulating PABPC1 expression through H3K27 acetylation. Therefore, SNHG14 may serve as a novel diagnostic and therapeutic target for breast cancer patients.

Exosome-mediated transfer of lncRNA­SNHG14 promotes trastuzumab chemoresistance in breast cancer.

Currently, resistance to trastuzumab, a human epidermal growth factor receptor 2 (HER2) inhibitor, has become an important obstacle to improving the clinical outcome of patients with advanced HER2+ breast cancer. While cell behavior may be modulated by long non­coding RNAs (lncRNAs), the contributions of lncRNAs within extracellular vesicles (exosomes) are largely unknown. To this end, the involvement and regulatory functions of potential lncRNAs contained within exosomes during the formation of chemoresistance in human breast cancer were investigated. Trastuzumab-resistant cell lines were established by continuously grafting HER2+ SKBR-3 and BT474 cells into trastuzumab-containing culture medium. An lncRNA microarray assay followed by reverse transcription­quantitative polymerase chain reaction analysis identified that lncRNA-small nucleolar RNA host gene 14 (SNHG14) was upregulated in trastuzumab-resistant cells when compared with parental breast cancer cells. Functional experimentation demonstrated that knockdown of lncRNA­SNHG14 potently promoted trastuzumab-induced cytotoxicity. Furthermore, extracellular lncRNA­SNHG14 was able to be incorporated into exosomes and transmitted to sensitive cells, thus disseminating trastuzumab resistance. Treatment of sensitive cells with exosomes highly expressing lncRNA­SNHG14 induced trastuzumab resistance, while knockdown of lncRNA­SNHG14 abrogated this effect. The Signal Transduction Reporter Array indicated that lncRNA­SNHG14 may promote the effect of trastuzumab by targeting the apoptosis regulator Bcl­2 (Bcl­2)/apoptosis regulator BAX (Bax) signaling pathway. Furthermore, the expression level of serum exosomal lncRNA­SNHG14 was upregulated in patients who exhibited resistance to trastuzumab, compared with patients exhibiting a response. Therefore, lncRNA­SNHG14 may be a promising therapeutic target for patients with HER2+ breast cancer.

Human dendritic cells engineered to secrete interleukin-18 activate MAGE-A3-specific cytotoxic T lymphocytes in vitro.

Adoptive cell transfer (ACT) involves the administration of tumor specific cytotoxic T lymphocytes (CTLs) into a patient to kill cancer cells. Although a promising cancer therapy, limitations on the generation of activated CTLs have restricted ATC's clinical application. Interleukin-18 (IL-18) is an interferon-γ (IFN-γ) inducing factor that plays an important functional role in regulating CTLs. Here, we attempt to use dendritic cells (DCs) modified with a recombinant adenovirus encoding IL-18 (rAd/IL-18) to improve the generation of activated tumor-specific CTLs. These engineered DCs secrete IL-18, increase the expression of co-stimulatory molecules, and enhance the cytotoxic efficacy of melanoma antigen 3 (MAGE-A3)-specific CTLs in vitro. We show that stimulation of CTLs with rAd/IL-18-loaded DCs increases the specific lysis of MAGE-A3-expressing human breast cancer MCF-7 cells, and at the same time increases the production of activated MAGE-A3-specific CTLs. Our results indicate that transducing DCs with rAd/IL-18 increases both the maturation of DCs and the activation level of MAGE-A3-specific CTLs, greatly enhancing the cytotoxic efficacy of CTLs towards tumor cells.

Carcinoma of the ampulla of Vater: factors influencing long-term survival of 127 patients with resection.

INTRODUCTION: The prognosis for patients with carcinoma of the ampulla of Vater is improved relative to other periampullary neoplasms. Identification of independent prognostic factors in ampullary carcinomas has been limited by the small number of tumors resected. The aim of the present study was to determine the clinicopathologic factors that influence long-term survival in patients with resected ampullary carcinoma. METHODS: Clinicopathologic data were retrospectively reviewed for patients with ampullary carcinomas radically resected between March 1987 and September 2002. The correlation between clinicopathologic variables and survival of patients after resection was examined by the Kaplan-Meier method, the log-rank test, and Cox proportional hazards regression. Ampullary carcinomas were radically resected in 127 patients either by pancreaticoduodenectomy (n = 124) or local resection (n = 3). RESULTS: Hospital mortality was 9.7%. The overall actuarial survival rates (including hospital deaths) at 1, 3, 5, and 10 years were 76.2%, 46.8%, 43.3%, and 35.7%, respectively. Factors that significantly influenced survival were lymph node status (P < 0.001), depth of tumor infiltration (P = 0.029), and TNM stage (P < 0.001) on univariate analysis. On multivariate analysis, both depth of infiltration and lymph node status were the independent determinants of survival after resection (P = 0.003, P = 0.005, respectively). CONCLUSIONS: Carcinoma of the ampulla of Vater has a higher resectability rate and a much better survival rate than pancreatic cancer. Pancreaticoduodenectomy is the treatment of choice for this tumor. Long-term survival was independently influenced by the depth of tumor infiltration and lymph node metastasis.