LncRNA FIRRE stimulates PTBP1-induced Smurf2 decay, stabilizes B-cell receptor, and promotes the development of diffuse large B-cell lymphoma.

Sustained expression of B-cell receptor (BCR) critically contributes to the development of diffuse large B-cell lymphoma (DLBCL). However, little is known on the mechanism regulating BCR expression. In the present study, we explored the biological significance of functional intergenic repeating RNA element (FIRRE) in DLBCL and its regulation on BCR. Functional impacts of FIRRE on cell viability, transformation, and apoptosis were examined by MTT, colony formation, and flow cytometry, respectively. The interaction between FIRRE and polypyrimidine tract binding protein 1 (PTBP1) was identified by RNA pull-down and verified using RNA immunoprecipitation (RIP) assays. The effects of FIRRE and PTBP1 on Smurf2 mRNA were examined by RIP, RNA pull-down, and mRNA stability assays. Smurf2-mediated BCR ubiquitination was investigated using co-immunoprecipitation, ubiquitination, and protein stability assays. In vivo, xenograft models were used to assess the impacts of targeting FIRRE on DLBCL growth. FIRRE was specifically up-regulated in and essentially maintained multiple malignant behaviors of BCR-dependent DLBCL cells. Through the interaction with PTBP1, FIRRE promoted the mRNA decay of Smurf2, a ubiquitin ligase for the degradation BCR protein. Targeting FIRRE was sufficient to regulat Smurf2 and BCR expressions and inhibit DLBCL malignancy both in vivo and in vitro. FIRRE-PTBP1 interaction, by simulating Smurf2 mRNA decay and stabilizing BCR, promotes the development of DLBCL. Consequently, targeting this signaling mechanism may provide therapeutic benefits for DLBCL.

LncRNA HCP5 acts as a miR-128-3p sponge to promote the progression of multiple myeloma through activating Wnt/ß-catenin/cyclin D1 signaling via PLAGL2.

BACKGROUND: Although long non-coding RNA (lncRNA) HCP plays essential roles in human cancers, its function and mechanism in multiple myeloma (MM) have not crystallized. METHODS: HCP5 level in MM was assessed through qRT-PCR. A series of functional investigations were conducted to evaluate the influences of HCP5 on proliferation and apoptosis. Bioinformatics analysis and RIP/RNA pull-down assays were carried out to determine the relationships among HCP5, miR-128-3p, and PLAGL2. Relative protein level was determined through Western blot. A xenograft tumor model was applied for validating the roles of HCP5/miR-128-3p/PLAGL2 axis in vivo. RESULTS: HCP5 was significantly increased in MM. HCP5 knockdown effectively thwarted the proliferative rate and cell cycle of MM cell lines and suppressed tumor growth. HCP5 regulated PLAGL2 expression by sponging miR-128-3p. PLAGL2 overexpression effectively rescued cells from influences by sh-HCP5 on cell proliferative and apoptotic rates. Additionally, HCP5 knockdown significantly inhibited Wnt/ß-catenin/cyclin D1 signaling, and these effects were eliminated by PLAGL2 overexpression. CONCLUSION: Our study revealed that HCP5/miR-128-3p/PLAGL2 is closely correlated to MM development by modulating Wnt/ß-catenin/cyclin D1 signaling. HCP5 promoted cell proliferation and tumor formation of MM cells by activating the Wnt/ß-catenin/CCND1 signaling pathway by sponging miR-128-3p to increase PLAGL2 expression.

Mesencephalic Astrocyte-Derived Neurotrophic Factor Inhibits Liver Cancer Through Small Ubiquitin-Related Modifier (SUMO)ylation-Related Suppression of NF-κB/Snail Signaling Pathway and Epithelial-Mesenchymal Transition.

BACKGROUND AND AIMS: Endoplasmic reticulum (ER) stress is associated with liver inflammation and hepatocellular carcinoma (HCC). However, how ER stress links inflammation and HCC remains obscure. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress-inducible secretion protein that inhibits inflammation by interacting with the key subunit of nuclear factor kappa light chain enhancer of activated B cells (NF-κB) p65. We hypothesized that MANF may play a key role in linking ER stress and inflammation in HCC. APPROACH AND RESULTS: Here, we found that MANF mRNA and protein levels were lower in HCC tissues versus adjacent noncancer tissues. Patients with high levels of MANF had better relapse-free survival and overall survival rates than those with low levels. MANF levels were also associated with the status of liver cirrhosis, advanced tumor-node-metastasis (TNM) stage, and tumor size. In vitro experiments revealed that MANF suppressed the migration and invasion of hepatoma cells. Hepatocyte-specific deletion of MANF accelerated N-nitrosodiethylamine (DEN)-induced HCC by up-regulating Snail1+2 levels and promoting epithelial-mesenchymal transition (EMT). MANF appeared in the nuclei and was colocalized with p65 in HCC tissues and in tumor necrosis factor alpha (TNF-α)-treated hepatoma cells. The interaction of p65 and MANF was also confirmed by coimmunoprecipitation experiments. Consistently, knockdown of MANF up-regulated NF-κB downstream target genes TNF-α, interleukin (IL)-6 and IL-1α expression in vitro and in vivo. Finally, small ubiquitin-related modifier 1 (SUMO1) promoted MANF nuclear translocation and enhanced the interaction of MANF and p65. Mutation of p65 motifs for SUMOylation abolished the interaction of p65 and MANF. CONCLUSIONS: MANF plays an important role in linking ER stress and liver inflammation by inhibiting the NF-κB/Snail signal pathway in EMT and HCC progression. Therefore, MANF may be a cancer suppressor and a potential therapeutic target for HCC.

GSE1 predicts poor survival outcome in gastric cancer patients by SLC7A5 enhancement of tumor growth and metastasis.

Gastric cancer remains a malignancy with poor survival outcome. We herein report that GSE1, a proline-rich protein, possesses a role in the progression of human gastric cancer. The expression of GSE1 was observed to be much higher in human gastric cancer tissues compared with normal gastric tissues, and GSE1 expression correlated positively with lymph node metastasis, histological grade, depth of invasion, and clinical stage in gastric cancer patients. Moreover, GSE1 expression was also associated with decreased post-operative relapse-free survival and overall survival in the cohort. The forced expression of GSE1 in gastric cancer cell lines resulted in increased cell proliferation, increased colony formation, enhanced cell migration, and invasion. Furthermore, forced expression of GSE1 also increased tumor size and enhanced lung metastasis in xenograft models. The depletion of endogenous GSE1 with shRNAs decreased the oncogenicity and invasiveness of gastric cancer cells both in vitro and in vivo In addition, GSE1 was determined to be a direct target of miR-200b and miR-200c. Furthermore, GSE1 positively regulated the downstream gene SLC7A5 (also known as LAT-1), which was scanned and verified from mRNA sequencing. GSE1 therefore possesses an oncogenic role in human gastric cancer, and targeted therapeutic approaches to inhibit GSE1 function in gastric cancer warrant further consideration.

NEK5 promotes breast cancer cell proliferation through up-regulation of Cyclin A2.

NEK5, a contraction of NIMA Related Kinase 5, has been shown to regulate the centrosome integrity of cells though; it has been little described in cancer. Herein, to explore the clinicopathological meaning of NEK5 expression in breast cancer, immunohistochemistry was performed to detect the expression of NEK5 on tissue blocks, totaling 203 cases. Quantitative real-time PCR (qRT-PCR) was used to evaluate NEK5 mRNA expression with 30 cases of fresh tissues. To observe the function of NEK5 in the growth of breast cancer cells, both MTT and xenografted nude mice were performed. And Transwell assay was employed to observe the variation of migration and invasion. It was shown that up-regulated NEK5 was significantly associated with tumor progression and poor overall prognosis; and that silencing of NEK5 can significantly suppress the proliferation both in vivo and in vitro, inhibiting migration, and invasion. To get insight into the underlying mechanism by which NEK5 operates in proliferation of breast cancer cells, we showed that NEK5 can up-regulate Cyclin A2 and down-regulate Cyclin D1, Cyclin D3, and Cyclin E1 expression. Additionally, Cyclin A2 was also identified as a novel interacting protein for NEK5. Taking together, we firstly defined the oncogenic role of NEK5 in breast cancer that was related to proliferation, supporting that NEK5 might be used a new therapeutic target in breast cancer.

TMED3 promotes cell proliferation and motility in breast cancer and is negatively modulated by miR-188-3p.

BACKGROUND: The role of TMED3 involved in cancers has been seldom described, let alone in breast cancer. To explore the clinicopathological significance of TMED3 expression and the biological roles involved in breast cancer cells, we undertook the study. METHODS: Immunohistochemistry was performed to observe the pattern of TMED3 expression in breast cancer tissues, totaling 224 cases; followed by detailed statistical analysis between TMED3 expression versus clinicopathological information available. To explore the role of TMED3 involved in the malignant behaviors of breast cancer cells, wound-healing and Transwell assays were conducted to evaluate the variation of migration and invasion of MCF-7 and MDA-MB-231 cells whose TMED3 has been stably silenced using lenti-viral based short hairpin RNA (shRNA) vectors. MTT, clonogenic assay and xenograft nude mice model were undertaken to observe the variation of proliferation both in vitro and in vivo. RESULTS: It was shown that elevated TMED3 markedly correlated with ER, PR, Her-2 status, and lymph nodes metastases in addition to significant association with poor overall prognosis. In vitro, TMED3 was shown to promote proliferation, migration and invasion of breast cancer cells. Moreover, miR-188-3p was identified as a novel negative regulator of TMED3 in breast cancer, which can slow down the proliferation, migration and invasion of MCF-7 cells. Results from in vivo xenograft nude mice models showed that lenti-viral based miR-188-3p re-expression can markedly impair the tumor growth. CONCLUSIONS: Our data define and bolster the oncogenic role of TMED3 in breast cancer.

Post-transcriptional regulation of ERBB2 by miR26a/b and HuR confers resistance to tamoxifen in estrogen receptor-positive breast cancer cells.

Tamoxifen-resistant (TAMR) estrogen receptor-positive (ER+) breast cancer is characterized by elevated Erb-B2 receptor tyrosine kinase 2 (ERBB2) expression. However, the underlying mechanisms responsible for the increased ERBB2 expression in the TAMR cells remain poorly understood. Herein, we reported that the ERBB2 expression is regulated at the post-transcriptional level by miR26a/b and the RNA-binding protein human antigen R (HuR), both of which associate with the 3'-UTR of the ERBB2 transcripts. We demonstrated that miR26a/b inhibits the translation of ERBB2 mRNA, whereas HuR enhances the stability of the ERBB2 mRNA. In TAMR ER+ breast cancer cells with elevated ERBB2 expression, we observed a decrease in the level of miR26a/b and an increase in the level of HuR. The forced expression of miR26a/b or the depletion of HuR decreased ERBB2 expression in the TAMR cells, resulting in the reversal of tamoxifen resistance. In contrast, the inactivation of miR26a/b or forced expression of HuR decreased tamoxifen responsiveness of the parental ER+ breast cancer cells. We further showed that the increase in HuR expression in the TAMR ER+ breast cancer cells is attributable to an increase in the HuR mRNA isoform with shortened 3'-UTR, which exhibits increased translational activity. This shortening of the HuR mRNA 3'-UTR via alternative polyadenylation (APA) was observed to be dependent on cleavage stimulation factor subunit 2 (CSTF2/CstF-64), which is up-regulated in the TAMR breast cancer cells. Taken together, we have characterized a model in which the interplay between miR26a/b and HuR post-transcriptionally up-regulates ERBB2 expression in TAMR ER+ breast cancer cells.

XIAP inhibits autophagy via XIAP-Mdm2-p53 signalling.

The primary role of autophagy is adaption to starvation. However, increasing evidence suggests that autophagy inhibition also plays an important role in tumorigenesis. Upregulation of X-linked inhibitor of apoptosis (XIAP) has been associated to a variety of human cancers, yet the underlying mechanisms remain obscure. Here, we report that XIAP suppresses autophagy by exerting a previously unidentified ubiquitin E3 ligase activity towards Mdm2, which is a negative regulator of p53. XIAP controls serum starvation-induced autophagy downstream of the PI3K/Akt pathway. In mouse models, inhibition of autophagy by XIAP promotes tumorigenecity of HCT116 cells. XIAP-mediated autophagy inhibition is also largely validated in clinical tumour samples. These findings reveal a novel XIAP-Mdm2-p53 pathway that mediates the inhibition of autophagy, by which XIAP may contribute to tumorigenesis.

XIAP 3'-untranslated region serves as a competitor for HMGA2 by arresting endogenous let-7a-5p in human hepatocellular carcinoma.

X-linked inhibitor of apoptosis protein functions as an intrinsic regulator of apoptosis by inhibition of caspase activity and possesses a pivotal role in human cancer development and progression. A growing body of literature has demonstrated that microRNAs lead to the degradation or translational repression of messenger RNAs by binding to the non-coding region of messenger RNA at the 3'-untranslated region. Here, we revealed that the expression of HMGA2 is upregulated with X-linked inhibitor of apoptosis protein after transfection of X-linked inhibitor of apoptosis protein 3'-untranslated region in hepatocellular carcinoma cells, suggesting that X-linked inhibitor of apoptosis protein 3'-untranslated region serves as a competitor for microRNAs and prevent the co-targeted messenger RNA, HMGA2, from being suppressed. We further identified that let-7a-5p could bind to both the X-linked inhibitor of apoptosis protein 3'-untranslated region and HMGA2 3'-untranslated region. Moreover, we demonstrated that the forced expression of X-linked inhibitor of apoptosis protein 3'-untranslated region increases the oncogenicity of hepatocellular carcinoma cells in vitro. Cell functional analyses were performed to examine the association of HMGA2 status and X-linked inhibitor of apoptosis protein 3'-untranslated region. We have also measured the functional readout of let-7a-5p and HMGA2, an assay often employed to provide substantial evidence for the effects of X-linked inhibitor of apoptosis protein 3'-untranslated region on hepatocellular carcinoma cells. In general, our findings suggest that X-linked inhibitor of apoptosis protein 3'-untranslated region serves as a competitive endogenous RNA for HMGA2 to activate hepatocellular carcinoma progression by arresting endogenous let-7a-5p.

Role of ARPC2 in Human Gastric Cancer.

Gastric cancer continues to be the second most frequent cause of cancer deaths worldwide. However, the exact molecular mechanisms are still unclear. Further research to find potential targets for therapy is critical and urgent. In this study, we found that ARPC2 promoted cell proliferation and invasion in the human cancer cell line MKN-28 using a cell total number assay, MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay, cell colony formation assay, migration assay, invasion assay, and wound healing assay. For downstream pathways, CTNND1, EZH2, BCL2L2, CDH2, VIM, and EGFR were upregulated by ARPC2, whereas PTEN, BAK, and CDH1 were downregulated by ARPC2. In a clinical study, we examined the expression of ARPC2 in 110 cases of normal human gastric tissues and 110 cases of human gastric cancer tissues. ARPC2 showed higher expression in gastric cancer tissues than in normal gastric tissues. In the association analysis of 110 gastric cancer tissues, ARPC2 showed significant associations with large tumor size, lymph node invasion, and high tumor stage. In addition, ARPC2-positive patients exhibited lower RFS and OS rates compared with ARPC2-negative patients. We thus identify that ARPC2 plays an aneretic role in human gastric cancer and provided a new target for gastric cancer therapy.

Autocrine/Paracrine Human Growth Hormone-stimulated MicroRNA 96-182-183 Cluster Promotes Epithelial-Mesenchymal Transition and Invasion in Breast Cancer.

Human growth hormone (hGH) plays critical roles in pubertal mammary gland growth, development, and sexual maturation. Accumulated studies have reported that autocrine/paracrine hGH is an orthotopically expressed oncoprotein that promotes normal mammary epithelial cell oncogenic transformation. Autocrine/paracrine hGH has also been reported to promote mammary epithelial cell epithelial-mesenchymal transition (EMT) and invasion. However, the underlying mechanism remains largely obscure. MicroRNAs (miRNAs) are reported to be involved in regulation of multiple cellular functions of cancer. To determine whether autocrine/paracrine hGH promotes EMT and invasion through modulation of miRNA expression, we performed microarray profiling using MCF-7 cells stably expressing wild type or a translation-deficient hGH gene and identified miR-96-182-183 as an autocrine/paracrine hGH-regulated miRNA cluster. Forced expression of miR-96-182-183 conferred on epithelioid MCF-7 cells a mesenchymal phenotype and promoted invasive behavior in vitro and dissemination in vivo. Moreover, we observed that miR-96-182-183 promoted EMT and invasion by directly and simultaneously suppressing BRMS1L (breast cancer metastasis suppressor 1-like) gene expression. miR-96 and miR-182 also targeted GHR, providing a potential negative feedback loop in the hGH-GHR signaling pathway. We further demonstrated that autocrine/paracrine hGH stimulated miR-96-182-183 expression and facilitated EMT and invasion via STAT3 and STAT5 signaling. Consistent with elevated expression of autocrine/paracrine hGH in metastatic breast cancer tissue, miR-96-182-183 expression was also remarkably enhanced. Hence, we delineate the roles of the miRNA-96-182-183 cluster and elucidate a novel hGH-GHR-STAT3/STAT5-miR-96-182-183-BRMS1L-ZEB1/E47-EMT/invasion axis, which provides further understanding of the mechanism of autocrine/paracrine hGH-stimulated EMT and invasion in breast cancer.

Artemin, a member of the glial cell line-derived neurotrophic factor family of ligands, is HER2-regulated and mediates acquired trastuzumab resistance by promoting cancer stem cell-like behavior in mammary carcinoma cells.

Previous studies have demonstrated that Artemin (ARTN) functions as a cancer stem cell (CSC) and metastatic factor in mammary carcinoma. Herein, we report that ARTN mediates acquired resistance to trastuzumab in HER2-positive mammary carcinoma cells. Ligands that increase HER2 activity increased ARTN expression in HER2-positive mammary carcinoma cells, whereas trastuzumab inhibited ARTN expression. Forced expression of ARTN decreased the sensitivity of HER2-positive mammary carcinoma cells to trastuzumab both in vitro and in vivo. Conversely, siRNA-mediated depletion of ARTN enhanced trastuzumab efficacy. Cells with acquired resistance to trastuzumab exhibited increased ARTN expression, the depletion of which restored trastuzumab sensitivity. Trastuzumab resistance produced an increased CSC population concomitant with enhanced mammospheric growth. ARTN mediated the enhancement of the CSC population by increased BCL-2 expression, and the CSC population in trastuzumab-resistant cells was abrogated upon inhibition of BCL-2. Hence, we conclude that ARTN is one mediator of acquired resistance to trastuzumab in HER2-positive mammary carcinoma cells.

Trefoil factor 3 promotes metastatic seeding and predicts poor survival outcome of patients with mammary carcinoma.

INTRODUCTION: Recurrence or early metastasis remains the predominant cause of mortality in patients with estrogen receptor positive (ER+) mammary carcinoma (MC). However, the molecular mechanisms underlying the initial progression of ER+ MC to metastasis remains poorly understood. Trefoil factor 3 (TFF3) is an estrogen-responsive oncogene in MC. Herein, we provide evidence for a functional role of TFF3 in metastatic progression of ER+ MC. METHODS: The association of TFF3 expression with clinicopathological parameters and survival outcome in a cohort of MC patients was assessed by immunohistochemistry. The expression of TFF3 in MCF7 and T47D cells was modulated by forced expression or siRNA-mediated depletion of TFF3. mRNA and protein levels were determined using qPCR and western blot. The functional effect of modulation of TFF3 expression in MC cells was determined in vitro and in vivo. Mechanistic analyses were performed using reporter constructs, modulation of signal transducer and activator of transcription 3 (STAT3) expression, and pharmacological inhibitors against c-SRC and STAT3 activity. RESULTS: TFF3 protein expression was positively associated with larger tumour size, lymph node metastasis, higher stage, and poor survival outcome. Forced expression of TFF3 in ER+ MC cells stimulated colony scattering, cell adhesion to a Collagen I-coated matrix, colony formation on a Collagen I- or Matrigel-coated matrix, endothelial cell adhesion, and transmigration through an endothelial cell barrier. In vivo, forced expression of TFF3 in MCF7 cells stimulated the formation of metastatic nodules in animal lungs. TFF3 regulation of the mRNA levels of epithelial, mesenchymal, and metastatic-related genes in ER+ MC cells were consistent with the altered cell behaviour. Forced expression of TFF3 in ER+ MC cells stimulated phosphorylation of c-SRC that subsequently increased STAT3 activity, which lead to the downregulation of E-cadherin. siRNA-mediated depletion of TFF3 reduced the invasiveness of ER+ MC cells. CONCLUSIONS: TFF3 expression predicts metastasis and poor survival outcome of patients with MC and functionally stimulates cellular invasion and metastasis of ER+ MC cells. Adjuvant functional inhibition of TFF3 may therefore be considered to ameliorate outcome of ER+ MC patients.

B-cell lymphoma 6 protein stimulates oncogenicity of human breast cancer cells.

BACKGROUND: B-cell lymphoma 6 (BCL6) protein, an evolutionarily conserved zinc finger transcription factor, showed to be highly expressed in various human cancers in addition to malignancies in the lymphoid system. This study investigated the role of BCL6 expression in breast cancer and its clinical significance in breast cancer patients. METHODS: Expression of BCL6 protein was assessed using in situ hybridization and immunohistochemistry in 127 breast cancer patients and 50 patients with breast benign disease as well as in breast cell lines. Expression of BCL6 was restored or knocked down in two breast cancer cell lines (MCF-7 and T47D) using BCL6 cDNA and siRNA, respectively. The phenotypic change of these breast cancer cell lines was assessed using cell viability MTT, Transwell invasion, colony formation, and flow cytometry assays and in a xenograft mice model. Luciferase reporter gene, immunoblot, and qRT-PCR were used to investigate the molecular events after manipulated BCL6 expression in breast cancer cells. RESULTS: BCL6 protein was highly expressed in breast cancer cell lines and tissue specimens and expression of BCL6 protein was associated with disease progression and poor survival of breast cancer patients. In vitro, the forced expression of BCL6 results in increased proliferation, anchorage-independent growth, migration, invasion and survival of breast cancer cell lines, whereas knockdown of BCL6 expression reduced these oncogenic properties of breast cancer cells. Moreover, forced expression of BCL6 increased tumor growth and invasiveness in a nude mouse xenograft model. At the gene level, BCL6 was a target gene of miR-339-5p. Expression of BCL6 induced expression of CXCR4 and cyclinD1 proteins. CONCLUSIONS: The current study demonstrated the oncogenic property of BCL6 in breast cancer and further study could target BCL6 as a novel potential therapeutic strategy for breast cancer.

Siva1 suppresses epithelial-mesenchymal transition and metastasis of tumor cells by inhibiting stathmin and stabilizing microtubules.

Epithelial-mesenchymal transition (EMT) enables epithelial cells to acquire motility and invasiveness that are characteristic of mesenchymal cells. It plays an important role in development and tumor cell metastasis. However, the mechanisms of EMT and their dysfunction in cancer cells are still not well understood. Here we report that Siva1 interacts with stathmin, a microtubule destabilizer. Siva1 inhibits stathmin's activity directly as well as indirectly through Ca(2+)/calmodulin-dependent protein kinase II-mediated phosphorylation of stathmin at Ser16. Via the inhibition of stathmin, Siva1 enhances the formation of microtubules and impedes focal adhesion assembly, cell migration, and EMT. Low levels of Siva1 and Ser16-phosphorylated stathmin correlate with high metastatic states of human breast cancer cells. In mouse models, knockdown of Siva1 promotes cancer dissemination, whereas overexpression of Siva1 inhibits it. These results suggest that microtubule dynamics are critical for EMT. Furthermore, they reveal an important role for Siva1 in suppressing cell migration and EMT and indicate that down-regulation of Siva1 may contribute to tumor cell metastasis.

[Expression of Fascin-1 protein in breast cancer and its clinicopathologic correlation].

OBJECTIVE: To study the expression of fascin-1 protein in breast cancer and to evaluate its correlation with clinicopathologic features of the tumor. METHODS: Immunohistochemical EnVision method was performed to evaluate the expression of fascin-1 in 23 cases of normal breast tissues, 69 cases of benign breast lesions, 58 cases of usual ductal hyperplasia (UDH), 61 cases of ductal carcinoma in situ (DCIS) and 221 cases of breast cancer from March 2007 to December 2011. RESULTS: Fascin-1 protein expression rates in normal breast tissues, benign breast lesions, UDH, DCIS and breast cancer were 100.0% (23/23), 89.9% (62/69), 13.8% (8/58), 19.7% (12/61), and 42.1% (93/221), respectively. Fascin-1 expression in normal breast tissues and benign breast lesions was significantly higher than those in UDH, DCIS and breast cancer (P < 0.01); Fascin-1 expression in breast cancer was significantly higher than those in UDH and DCIS (P < 0.01). There was a tendency of increased fascin-1 expression in DCIS compared to UDH, but the difference was not statistically significant (P > 0.05). Fascin-1 positive rates in patients with DCIS grade III (26.8%, 11/41) was significantly higher than that in patients with DCIS grade I-II (1/20, P < 0.05). Fascin-1 protein expression in breast cancer increased with increasing histologic grade and clinical stage (P < 0.01). Fascin-1 protein expression was also significantly higher in tumors with negative estrogen receptor (ER) and progestone receptor (PR) status and > 3 axillary lymph node metastases compared to tumors that were ER and PR positive and ≤ 3 axillary lymph node metastases (P < 0.01 and P < 0.05, respectively). Logistic regression analysis showed that fascin-1 expression correlated positively with high clinical stage (OR = 1.568, 95% CI = 1.029-2.387, P < 0.05) , but negatively with ER expression (OR = 0.149, 95% CI = 0.079-0.281, P < 0.01) . CONCLUSIONS: Fascin-1 is highly expressed in normal breast tissues and benign breast lesions, suggesting that it may be a biological marker of mature mammary ductal epithelium. Fascin-1 protein expression shows a significantly increasing trend from UDH, DCIS to invasive breast cancer, suggesting that fascin-1 plays an important role in breast carcinogenesis and may be a potential target for therapy.

[Expression of the LC3A protein in prostate cancer and its implications].

OBJECTIVE: To investigate the expression of the LC3A protein in prostate cancer (PCa) and its clinicopathological significance. We detected the expression of the LC3A protein by immunohistochemistry in 54 cases of PCa and 14 cases of benign prostatic hyperplasia (BPH), and analyzed the correlation between the LC3A expression and the clinicopathological parameters in PCa. The positive signals of the LC3A protein were located in the cytoplasm and/or cell nuclei. The rate of its strongly positive expression was 90.7% in PCa, significantly higher than 14.3% in BPH (P < 0.01). The LC3A expression was also found in the cell nuclei of 22 cases of PCa, with no significant correlation to that in the cytoplasm (P > 0.05). The expression of LC3A was significantly correlated with Gleason scores (r = 0.297, P = 0.029 in cytoplasm; r = 0.288, P = 0.034 in cell nuclei), but not with the clinical stage, patient's age, androgen receptor (AR) level and preoperative levels of serum PSA and cPSA (all P > 0.05). LC3A was also expressed in the fibrocytes and smooth muscle cells in PCa and BPH. The positive rate of AR was 74.1% (40/54) in PCa and 64.3% (9/14) in BPH, with no significant difference between the two groups (P > 0.05). CONCLUSION: The expression of the LC3A protein might be involved in the development, differentiation, and prognosis of prostate cancer.

LINC00460-FUS-MYC feedback loop drives breast cancer metastasis and doxorubicin resistance.

Therapeutic resistance and metastasis largely contribute to mortality from breast cancer and therefore understanding the underlying mechanisms of such remains an urgent challenge. By cross-analysis of TCGA and GEO databases, LINC00460 was identified as an oncogenic long non-coding RNA, highly expressed in Doxorubicin resistant breast cancer. LINC00460 was further demonstrated to promote stem cell-like and epithelial-mesenchymal transition (EMT) characteristics in breast cancer cells. LINC00460 interacts with FUS protein with consequent enhanced stabilization, which further promotes MYC mRNA maturation. LINC00460 expression was transcriptionally enhanced by c-MYC protein, forming a positive feedback loop to promote metastasis and Doxorubicin resistance. LINC00460 depletion in Doxorubicin-resistant breast cancer cells restored sensitivity to Doxorubicin and increased the efficacy of c-MYC inhibitor therapy. Collectively, these findings implicate LINC00460 as a promising prognostic biomarker and potential therapeutic target to overcome Doxorubicin resistance in breast cancer.

Artemin stimulates radio- and chemo-resistance by promoting TWIST1-BCL-2-dependent cancer stem cell-like behavior in mammary carcinoma cells.

Artemin (ARTN) has been reported to promote a TWIST1-dependent epithelial to mesenchymal transition of estrogen receptor negative mammary carcinoma (ER-MC) cells associated with metastasis and poor survival outcome. We therefore examined a potential role of ARTN in the promotion of the cancer stem cell (CSC)-like phenotype in mammary carcinoma cells. Acquired resistance of ER-MC cells to either ionizing radiation (IR) or paclitaxel was accompanied by increased ARTN expression. Small interfering RNA (siRNA)-mediated depletion of ARTN in either IR- or paclitaxel-resistant ER-MC cells restored cell sensitivity to IR or paclitaxel. Expression of ARTN was enriched in ER-MC cells grown in mammospheric compared with monolayer culture and was also enriched along with BMI1, TWIST1, and DVL1 in mammospheric and ALDH1+ populations. ARTN promoted mammospheric growth and self-renewal of ER-MC cells and increased the ALDH1+ population, whereas siRNA-mediated depletion of ARTN diminished these CSC-like cell behaviors. Furthermore, increased ARTN expression was significantly correlated with ALDH1 expression in a cohort of ER-MC patients. Forced expression of ARTN also dramatically enhanced tumor initiating capacity of ER-MC cells in xenograft models at low inoculum. ARTN promotion of the CSC-like cell phenotype was mediated by TWIST1 regulation of BCL-2 expression. ARTN also enhanced mammosphere formation and the ALDH1+ population in estrogen receptor-positive mammary carcinoma (ER+MC) cells. Increased expression of ARTN and the functional consequences thereof may be one common adaptive mechanism used by mammary carcinoma cells to promote cell survival and renewal in hostile tumor microenvironments.