CDK12 activates MYC to repress miR-28-5p/EZH2 and amplifies tonic BCR signaling to promote the development of diffuse large B-cell lymphoma.

Cyclin-dependent kinase 12 (CDK12) is a transcription-associated kinase that participates in various cellular processes. However, its regulatory role in the progression of diffuse large B-cell lymphoma (DLBCL), which is the most prevalent subtype of non-Hodgkin lymphoma (NHL), is still elusive and controversial.The expression of CDK12 was detected by immunohistochemistry (IHC), RT-qPCR was performed to detect miR-28-5p expression of OCI-LY3 and SU-DHL-4 cells. MTT and soft agarose colony formation assays were used to detect cell proliferation. The cell apoptosis was determined by flow cytometry. The protein expressions changes of MYC, EZH2 and the biomarkers of BCR signaling were also detected. A subcutaneous transplantation tumor model of OCI-LY3 cells in nude mice was established to evaluate anticarcinogenic activities of CDK12 knockdown. Elevated expression of CDK12 was observed while miR-28-5p was downregulated in DLBCL tissues. CDK12 knockdown or miR-28-5p overexpression could inhibit proliferation and promote apoptosis of DLBCL cells. miR-28-5p inhibition could reverse the effect of CDK12 knockdown on proliferation and apoptosis of DLBCL cells. In addition, CDK12 knockdown could inhibit DLBCL tumor growth in the mice model. CDK12 activated MYC to repress miR-28-5p/EZH2 and amplified tonic BCR signaling to promote the development of DLBCL, which might provide potential therapeutic targets for future therapeutic intervention in DLBCL.

Clinical Relevance and Prognostic Value of the Neuronal Protein Neuroligin 2 in Breast Cancer.

Neuroligin 2 (NLGN2) is a well-recognized transmembrane scaffolding protein that functions in synapse development and neuronal signal transduction. It has recently been implicated in multiple diseases of peripheral ectodermal origin. However, the potential roles of NLGN2 in tumors remain ill-defined. The aim of this study was to determine the clinical relevance and prognostic value of NLGN2 in breast cancer. To this end, breast cancer datasets were extracted from TCGA and other public databases, and subjected to Kaplan-Meier potter for survival analysis, GEPIA2 for assessing the immunological relevance of NLGN2 and THPA for identifying its subcellular localization. The in-silico results were further validated by immunohistochemistry analysis of in-house tumor tissue specimens. NLGN2 was identified as a prognostic factor in breast cancer subtypes, and its high expression correlated to a favorable survival outcome. Moreover, NLGN2 overexpression in breast cancer was significantly associated with large tumor size, lymph node metastasis, late TNM stage, and high histological grade. Interestingly, there was a significant correlation between the expression level of NLGN2 and the immunomodulatory molecules, along with increased interstitial infiltration of lymphocytes. Furthermore, NLGN2 was predominantly localized in the mitochondria of breast cancer cells. In conclusion, NLGN2 has a prognostic role and immunoregulatory potential in breast cancer, and its functions likely have a mitochondrial basis. It is a promising therapeutic target in breast cancer and should be explored further.

ARTEMIN Promotes Oncogenicity and Resistance to 5-Fluorouracil in Colorectal Carcinoma by p44/42 MAPK Dependent Expression of CDH2.

ARTEMIN (ARTN), one of the glial-cell derived neurotrophic factor family of ligands, has been reported to be associated with a number of human malignancies. In this study, the enhanced expression of ARTN in colorectal carcinoma (CRC) was observed; the expression of ARTN positively correlated with lymph node metastases and advanced tumor stages and predicted poor prognosis. Forced expression of ARTN in CRC cells enhanced oncogenic behavior, mesenchymal phenotype, stem cell-like properties and tumor growth and metastasis in a xenograft model. These functions were conversely inhibited by depletion of endogenous ARTN. Forced expression of ARTN reduced the sensitivity of CRC cells to 5-FU treatment; and 5-FU resistant CRC cells harbored enhanced expression of ARTN. The oncogenic functions of ARTN were demonstrated to be mediated by p44/42 MAP kinase dependent expression of CDH2 (CADHERIN 2, also known as N-CADHERIN). Inhibition of p44/42 MAP kinase activity or siRNA mediated depletion of endogenous CDH2 reduced the enhanced oncogenicity and chemoresistance consequent to forced expression of ARTN induced cell functions; and forced expression of CDH2 rescued the reduced mesenchymal properties and resistance to 5-FU after ARTN depletion. In conclusion, ARTN may be of prognostic and theranostic utility in CRC.

Pan-Cancer Prognostic Role and Targeting Potential of the Estrogen-Progesterone Axis.

INTRODUCTION: Estrogen receptors (ESRs) and progesterone receptors (PGRs) are associated with the development and progression of various tumors. The feasibility of ESRs and PGRs as prognostic markers and therapeutic targets for multiple cancers was evaluated via pan-cancer analysis. METHODS: The pan-cancer mRNA expression levels, genetic variations, and prognostic values of ESR1, ESR2, and PGR were analyzed using the Gene Expression Profiling Interactive Analysis 2 (GEPIA2) and cBioPortal. The expression levels of ERa, ERb, and PGR proteins were detected by immunohistochemical staining using paraffin-embedded tissue specimens of ovarian serous cystadenocarcinoma (OV) and uterine endometrioid adenocarcinoma (UTEA). Correlation between immunomodulators and immune cells was determined based on the Tumor and Immune System Interaction Database (TISIDB). RESULTS: ESR1, ESR2, and PGR mRNAs were found to be differentially expressed in different cancer types, and were associated with tumor progression and clinical prognosis. ERa, ERb, and PGR proteins were further determined to be significantly differentially expressed in OV and UTEA via immunohistochemical staining. The expression of ERa protein was positively correlated with a high tumor stage, whereas the expression of PGR protein was conversely associated with a high tumor stage in patients with OV. In patients with UTEA, the expression levels of both ERa and PGR proteins were conversely associated with tumor grade and stage. In addition, the expression levels of ESR1, ESR2, and PGR mRNAs were significantly associated with the expression of immunomodulators and immune cells. CONCLUSION: ESR1, ESR2, and PGR are potential prognostic markers and therapeutic targets, as well as important factors for the prediction, evaluation, and individualized treatment in several cancer types.

Predicted the P2RX7 rs3751143 polymorphism is associated with cancer risk: a meta-analysis and systematic review.

BACKGROUND: Both meta-analyses and systematic reviews were used to assess the relationship between purinergic receptor P2X ligand-gated ion channel 7 (P2RX7) rs3751143 polymorphism and the risk of cancer. MATERIALS AND METHODS: The data used in this research were collected from Google Scholar, Web of Science, CNKI, and Wan Fang Data databases. The final retrieval ended on 22 February 2019. The strength of correlation was assessed using odds ratios and 95% confidence intervals. Based on the heterogeneity test results, fixed-effect (Mantel-Haenszel) or random-effects (DerSimonian-Laird) models were selected to summarise the collective effects. RESULTS: Eight separate studies containing 1462 cancer cases and 3037 controls were enrolled. Overall, there was no significant association between P2RX7 rs3751143 polymorphism and the risk of cancer in the allelic, homozygous, heterozygous, dominant, or recessive models. CONCLUSIONS: Our meta-analysis indicates that there is no significant association between P2RX7 rs3751143 polymorphism and the risk of cancer in the allelic, homozygous, heterozygous, dominant, and recessive models.

NUDT21 Suppresses Breast Cancer Tumorigenesis Through Regulating CPSF6 Expression.

BACKGROUND: NUDT21, an RNA binding protein, has been reported to play an important role in the regulation of multiple biological responses. Detection of NUDT21 expression may lead to the identification of a novel marker for breast cancer. PURPOSE: The aim of this study was to investigate the clinical significance and functional role of NUDT21 in breast cancer. METHODS: The protein expression of NUDT21 was examined by immunohistochemistry (IHC) in 100 paraffin-embedded, archived breast cancer samples and 100 benign breast tissues. Then, the correlations between the NUDT21 expression and clinicopathologic characteristics and prognoses of the breast cancer patients were analyzed. In addition, the function of NUDT21 in breast cancer cell lines was detected by the methyl thiazolyl tetrazolium, colony formation and transwell assays. Finally, mass spectrometry analysis and Western blotting were used to identify the proteins that interact directly with NUDT21. RESULTS: IHC analysis revealed that the expression of NUDT21 was significantly lower in breast cancer tissues compared with benign breast disease tissues. The correlation analysis revealed that low expression of NUDT21 was positively correlated with tumor size, lymph node metastasis, and TNM stage. Also, Kaplan-Meier survival curves showed that patients with lower NUDT21 expression had shorter overall survival and relapse-free survival compared with higher NUDT21 expression. In addition, the knockdown of NUDT21 enhanced cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT). Consistently, the overexpression of NUDT21 inhibited cell proliferation, migration, invasion, and EMT. In addition, NUDT21 directly interacted with CPSF6 and negatively regulated its expression. Moreover, the knockdown of CPSF6 reversed NUDT21 expression-induced cancer cell migration and invasion. CONCLUSION: NUDT21 might play a tumor-suppressive role by inhibiting cell proliferation and invasion via the NUDT21/CPSF6 signaling pathway in breast cancer cells.

A novel small-molecule inhibitor of trefoil factor 3 (TFF3) potentiates MEK1/2 inhibition in lung adenocarcinoma.

TFF3 has been identified as a novel biomarker to distinguish between lung adenocarcinoma (ADC) and lung squamous-cell carcinoma (SCC). Herein, we determined the oncogenic functions of TFF3 and demonstrated the potential of pharmacological inhibition of TFF3 in lung ADC using a novel small-molecule inhibitor of TFF3 dimerization (AMPC). Forced expression of TFF3 in lung ADC cells enhanced cell proliferation and survival, increased anchorage-independent growth, cancer stem cell behavior, growth in 3D Matrigel, and cell migration and invasion. In contrast, depleted expression of TFF3 suppressed these cellular functions. Mechanistically, TFF3 exerted its oncogenic function through upregulation of ARAF and hence enhanced downstream activation of MEK1/2 and ERK1/2. Pharmacological inhibition of TFF3 by AMPC, resulted in markedly decreased cell survival, proliferation, 3D growth and foci formation, and impaired tumor growth in a xenograft mouse model. Moreover, the combination of various MEK1/2 inhibitors with AMPC exhibited synergistic inhibitory effects on lung ADC cell growth. In conclusion, this study provides the first evidence that TFF3 is a potent promoter of lung ADC progression. Targeting TFF3 with a novel small-molecule inhibitor alone or in combination with conventional MEK1/2 inhibitors are potential strategies to improve the outcome of lung ADC.

The oncogenic impact of RNF2 on cell proliferation, invasion and migration through EMT on mammary carcinoma.

Mammary carcinoma (MC) is one of most common malignancy in women, and ring finger protein 2 (RNF2) possesses various roles in vast human tumors. In MC tissues as well as in cell lines RNF2 exhibited high expression, had significant association with tumor size, lymph node status, TNM stage, patients' poor survival, and promoted cell proliferation, colony formation, cell migration and invasion of MC cell lines which was mediated by downregulation of E-cadherin protein. These data reveal that RNF2 protein plays a vital role in the development of MC and may be a potential therapy target of MC.

Expression of two non-mutated genetic elements is sufficient to stimulate oncogenic transformation of human mammary epithelial cells.

Trefoil factor 3 (TFF3) expression is positively associated with advanced clinicopathological features of mammary carcinoma (MC). Herein, we provide evidence for a functional role of TFF3 in oncogenic transformation of immortalized, but otherwise normal human mammary epithelial cells (HMECs), namely, HMEC-hTERT, MCF10A, and MCF12A. Forced expression of TFF3 in immortalized-HMECs enhanced cell proliferation, cell survival, anchorage-independent growth, produced highly disorganised three-dimensional (3D) acinar structures and generated tumours in immunocompromised mice. Forced expression of TFF3 in immortalized-HMECs stimulated STAT3 activity that was required for TFF3-stimulated cell proliferation, survival, and anchorage-independent growth. TFF3 specifically utilised STAT3 activity to govern a transcriptional program, which was required for TFF3-stimulated oncogenic transformation of immortalized-HMECs, including transcriptional upregulation of CCND1 and BCL2. siRNA-mediated depletion or functional inhibition of STAT3 significantly inhibited the TFF3-stimulated transcription of CCND1 and BCL2 and oncogenicity in immortalized-HMECs. Furthermore, DOX-inducible expression of TFF3 in HMEC-hTERT cells also permitted anchorage-independent growth and produced disorganized acinar structures in 3D Matrigel culture. Removal of DOX-induced expression of TFF3 in HMEC-hTERT cells, previously grown with DOX, resulted in efficient normalisation of the disorganized acinar architecture and attenuated cell viability in Matrigel culture. Cumulatively, these findings suggest that TFF3 is a potent oncogene and its increased expression along with hTERT in HMECs is sufficient to produce oncogenic transformation.

Autocrine hGH stimulates oncogenicity, epithelial-mesenchymal transition and cancer stem cell-like behavior in human colorectal carcinoma.

Tumor derived human growth hormone (hGH) has been implicated in cancer development and progression. However, the specific functional role of autocrine/paracrine hGH in colorectal cancer (CRC) remains largely to be determined. Herein, we demonstrated a crucial oncogenic role of autocrine hGH in CRC progression. Elevated hGH expression was detected in CRC compared to normal colorectal tissue, and hGH expression in CRC was positively associated with tumor size and lymph node metastasis. Forced expression of hGH stimulated cell proliferation, survival, oncogenicity and epithelial to mesenchymal transition (EMT) of CRC cells, and promoted xenograft growth and local invasion in vivo. Autocrine hGH expression in CRC cells stimulated the activation of the ERK1/2 pathway, which in turn resulted in increased transcription of the mesenchymal marker FIBRONECTIN 1 and transcriptional repression of the epithelial marker E-CADHERIN. The autocrine hGH-stimulated increase in CRC cell proliferation, cell survival and EMT was abrogated upon ERK1/2 inhibition. Furthermore, autocrine hGH-stimulated CRC cell migration and invasion was dependent on the ERK1/2-mediated increase in FIBRONECTIN 1 expression and decrease in E-CADHERIN expression. Forced expression of hGH also enhanced CSC-like behavior of CRC cells, as characterized by increased colonosphere formation, ALDH-positive population and CSC marker expression. Autocrine hGH-enhanced cancer stem cell (CSC)-like behavior in CRC cells was also observed to be E-CADHERIN-dependent. Thus, autocrine hGH plays a critical role in CRC progression, and inhibition of hGH could be a promising targeted therapeutic approach to limit disease progression in metastatic CRC patients.

Hypomethylation associated enhanced transcription of trefoil factor-3 mediates tamoxifen-stimulated oncogenicity of ER+ endometrial carcinoma cells.

Tamoxifen (TAM) is widely used as an adjuvant therapy for women with breast cancer (BC). However, TAM possesses partial oestrogenic activity in the uterus and its use has been associated with an increased incidence of endometrial carcinoma (EC). The molecular mechanism for these observations is not well understood. Herein, we demonstrated that forced expression of Trefoil factor 3 (TFF3), in oestrogen receptor-positive (ER+) EC cells significantly increased cell cycle progression, cell survival, anchorage-independent growth, invasiveness and tumour growth in xenograft models. Clinically, elevated TFF3 protein expression was observed in EC compared with normal endometrial tissue, and its increased expression in EC was significantly associated with myometrial invasion. TAM exposure increased expression of TFF3 in ER+ EC cells and its elevated expression resulted in increased oncogenicity and invasiveness. TAM-stimulated expression of TFF3 in EC cells was associated with hypomethylation of the TFF3 promoter sequence and c-JUN/SP1-dependent transcriptional activation. In addition, small interfering (si) RNA-mediated depletion or polyclonal antibody inhibition of TFF3 significantly abrogated oncogenicity and invasiveness in EC cells consequent to TAM induction or forced expression of TFF3. Hence, TAM-stimulated upregulation of TFF3 in EC cells was critical in promoting EC progression associated with TAM treatment. Importantly, inhibition of TFF3 function might be an attractive molecular modality to abrogate the stimulatory effects of TAM on endometrial tissue and to limit the progression of EC.

Expression of and correlation between BCL6 and ZEB family members in patients with breast cancer.

B-cell lymphoma 6 (BCL6), a proto-oncogene, is an evolutionarily conserved zinc finger protein that functions as a transcriptional repressor. BCL6 is the master regulator of B-lymphocyte development, and it has been reported that BCL6 may serve an important role in breast cancer progression. The aim of the present study was to investigate the expression of BCL6, zinc finger E-box-binding homeobox (ZEB)1 and ZEB2 and their associations in breast cancer. The mRNA and protein expression of BCL6, ZEB1 and ZEB2 was assessed using in situ hybridization and immunohistochemistry, respectively, in 228 patients with breast cancer and 80 patients with benign breast disease. In addition, the association between BCL6, ZEB1 and ZEB2 expression and the clinicopathological characteristics and survival of patients with breast cancer were analyzed. The mRNA and protein expression of BCL6, ZEB1 and ZEB2 were significantly higher in breast cancer tissues compared with benign breast disease tissues (P<0.05). The expression of BCL6, ZEB1 and ZEB2 were significantly positively correlated with tumor size, lymph node metastasis and a higher tumor stage (P<0.05). Furthermore, patients with BCL6, ZEB1 and ZEB2 protein-positive primary tumors had significantly lower overall survival (P=0.001, 0.002 and 0.001, respectively) and relapse-free survival (P=0.002, 0.001 and 0.003, respectively) rates. The mRNA expressions of ZEB1 (rs=0.326, P<0.001) and ZEB2 (rs=0.382, P<0.001) were significantly positively correlated with BCL6 mRNA expression, and the protein expressions of ZEB1 ((rs=0.449, P<0.001) and ZEB2 (rs=0.669, P<0.001) were significantly positively correlated with BCL6 protein expression. These results suggest that BCL6, ZEB1 and ZEB2 are potential biomarkers for the invasion, metastasis and prognosis of breast cancer, and that BCL6 may be a regulator of the ZEB family.

MiR-23a modulates X-linked inhibitor of apoptosis-mediated autophagy in human luminal breast cancer cell lines.

Autophagy is a conserved multi-step lysosomal process that is induced by diverse stimuli including cellular nutrient deficiency. X-linked inhibitor of apoptosis (XIAP) promotes cell survival and recently has been demonstrated to suppress autophagy. Herein, we examined regulation of XIAP-mediated autophagy in breast cancer cells and determined the underlying molecular mechanism. To investigate this process, autophagy of breast cancer cells was induced by Earle's balanced salt solution (EBSS). We observed discordant expression of XIAP mRNA and protein in the autophagic process induced by EBSS, suggesting XIAP may be regulated at a post-transcriptional level. By scanning several miRNAs potentially targeting XIAP, we observed that forced expression of miR-23a significantly decreased the expression of XIAP and promoted autophagy, wherever down-regulation of miR-23a increased XIAPexpression and suppressed autophagy in breast cancer cells. XIAP was confirmed as a direct target of miR-23a by reporter assay utilizing the 3'UTR of XIAP. In vitro, forced expression of miR-23a promoted autophagy, colony formation, migration and invasion of breast cancer cell by down-regulation of XIAP expression. However, miR-23a inhibited apoptosis of breast cancer cells independent of XIAP. Xenograft models confirmed the effect of miR-23a on expression of XIAP and LC3 and that miR-23a promoted breast cancer cell invasiveness. Therefore, our study demonstrates that miR-23a modulates XIAP-mediated autophagy and promotes survival and migration in breast cancer cells and hence provides important new insights into the understanding of the development and progression of breast cancer.

CMIP Promotes Proliferation and Metastasis in Human Glioma.

Glioma is one of the most common primary malignant brain tumors and the outcomes are generally poor. The intrinsic mechanisms involved in glioma development and progression remain unclear. Further studies are urgent and necessary. In this study, we have proven that CMIP (C-Maf-inducing protein) promotes cell proliferation and metastasis in A172 cells through knockdown of CMIP and in U251 cells through overexpression of CMIP by using MTT assay, cell colony formation assay, cell migration assay, and cell invasion assay. Furthermore, we discovered that CMIP upregulates MDM2, which is involved in the promoting role of CMIP in human glioma cells. For clinical study, 99 glioma tissues and 59 normal tissues were analyzed. CMIP expression was higher in glioma tissues than in normal tissues. In glioma tissues, CMIP is found to correlate positively with tumor grade but no significant correlation is found with patients' age, gender, or Karnofsky performance score (KPS). Moreover, CMIP also correlates with low relapse-free survival (RFS) rate and overall survival (OS) rate in glioma patients. Therefore, CMIP is oncogenic and could be a potential target for human glioma diagnosis and therapy.

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.

Tumour-Derived Human Growth Hormone As a Therapeutic Target in Oncology.

The growth hormone (GH) and insulin-like growth factor-1 (IGF1) axis is the key regulator of longitudinal growth, promoting postnatal bone and muscle growth. The available data suggest that GH expression by tumour cells is associated with the aetiology and progression of various cancers such as endometrial, breast, liver, prostate, and colon cancer. Accordingly there has been increased interest in targeting GH-mediated signal transduction in a therapeutic setting. Because GH has endocrine, autocrine, and paracrine actions, therapeutic strategies will need to take into account systemic and local functions. Activation of related hormone receptors and crosstalk with other signalling pathways are also key considerations.

Trefoil factor 3 mediation of oncogenicity and chemoresistance in hepatocellular carcinoma is AKT-BCL-2 dependent.

The efficacious treatment of hepatocellular carcinoma (HCC) remains a challenge, partially being attributed to intrinsic chemoresistance. Previous reports have observed increased TFF3 expression in HCC. Herein, we investigated the functional role of TFF3 in progression of HCC, and in both intrinsic and acquired chemoresistance. TFF3 expression was observed to be upregulated in HCC and associated with poor clinicopathological features and worse patient survival outcome. Functionally, forced expression of TFF3 in HCC cell lines increased cell proliferation, cell survival, anchorage-independent and 3D matrigel growth, cell invasion and migration, and in vivo tumor growth. In contrast, depleted expression of TFF3 decreased the oncogenicity of HCC cells as indicated by the above parameters. Furthermore, forced expression of TFF3 decreased doxorubicin sensitivity of HCC cells, which was attributed to increased doxorubicin efflux and cancer stem cell-like behavior of Hep3B cells. In contrast, depletion of TFF3 increased doxorubicin sensitivity and decreased cancer stem cell-like behavior of Hep3B cells. Correspondingly, TFF3 expression was markedly increased in Hep3B cells with acquired doxorubicin resistance, while the depletion of TFF3 resulted in re-sensitization of the Hep3B cells to doxorubicin. The increased doxorubicin efflux and enhanced cancer stem cell-like behavior of the doxorubicin-resistant Hep3B cells was observed to be dependent on TFF3 expression. In addition, we determined that TFF3-stimulated oncogenicity and chemoresistance in HCC cells was mediated by AKT-dependent expression of BCL-2. Hence, therapeutic inhibition of TFF3 should be considered to hinder HCC progression and overcome intrinsic and acquired chemoresistance in HCC.

XIAP 3'-untranslated region as a ceRNA promotes FSCN1 function in inducing the progression of breast cancer by binding endogenous miR-29a-5p.

The non-coding 3'-untranslated region (UTR) of genes play an important role in the regulation of microRNA (miRNA) functions, since it can bind and inactivate multiple miRNAs. Herein, we report that ectopic expression of XIAP 3'UTR increased human breast cancer cells proliferation, colony formation, migration, invasion and xenograft tumor growth and suppressed tumor cell death. To investigate this process, we further correlated the genome-wide transcriptional profiling with the gene expression alterations after transfecting XIAP 3'UTR in MCF-7 cells. We identified a robust, genome-wide mechanism of cell migration, motility and epithelial to mesenchymal transition by which mediated by a previously described cellular component movement factor FSCN1. Expression of XIAP and FSCN1 were up-regulated synergistically after transfecting XIAP 3'UTR in vitro and in vivo. Interactions between XIAP and FSCN1 appear to be a key determinant of these processes. Co-transfection with Dicer siRNA reversed the XIAP 3'UTR-mediated oncogenicity, suggesting the miRNAs might be involved in that process. Furthermore, we demonstrated that one miRNA, miR-29a-5p, can bind to both the XIAP and FSCN1 3'UTRs and play an important role in that interactions. We showed that the 3'UTR of XIAP was able to antagonize miR-29a-5p, and resulted in the increased translation of XIAP and FSCN1. Thus, our findings reveal important new insights into how XIAP 3'UTR works, suggesting that the non-coding XIAP 3'UTR serves as a competitor for miRNA binding and subsequently inactivates miRNA functions, by which XIAP 3'UTR frees the target mRNAs from being repressed.

Prolactin Inhibits BCL6 Expression in Breast Cancer Cells through a MicroRNA-339-5p-Dependent Pathway.

PURPOSE: Prolactin (PRL) plays a critical role in breast cancer progression by activating its cognate receptor and promotes the growth and differentiation of breast cancer cells. Studies have shown that B-cell lymphoma 6 (BCL6) is the target gene of microRNA-339-5p (miR-339-5p) and that BCL6 expression contributes to breast cancer progression. Herein, we identified PRL as a potent suppressor of BCL6 expression in human breast cancer cells. METHODS: Western blotting and quantitative reverse transcription-polymerase chain reaction were used to investigate molecular mechanisms underlying miR-339-5p expression and BCL6 manipulation in MCF-7, T47D, and SKBR3 breast cancer cells. Phenotypic changes in these breast cancer cell lines were assessed by performing cell viability (MTT), colony formation, migration, and invasion assays. RESULTS: PRL suppressed BCL6 protein and mRNA expression and upregulated miR-339-5p expression in MCF-7 and T47D breast cancer cells. Selective downregulation of miR-339-5p expression significantly reversed PRL-induced suppression of BCL6 mRNA and protein expression. Exogenous PRL stimulation significantly decreased the proliferation, colony formation, migration, and invasion of breast cancer cells, and suppression of miR-339-5p expression reversed these processes in vitro. CONCLUSION: These results indicated that PRL inhibited BCL6 expression and regulated breast cancer progression through a miR-339-5p-dependent pathway.