BRCC2 inhibits breast cancer cell growth and metastasis in vitro and in vivo via downregulating AKT pathway

Riddle of the Sphinx: Emerging role of circular RNAs in cervical cancer

Cervical cancer is a prominent cause of cancer-related mortality among women, with recent attention directed toward exploring the involvement of circular RNAs (circRNAs) in this particular cancer. CircRNAs, characterized by a covalently closed loop structure, belong to a class of single-stranded non-coding RNA (ncRNA) molecules that play crucial roles in cancer development and progression through diverse mechanisms. The abnormal expression of circRNAs in vivo is significantly associated with the development of cervical cancer. Notably, circRNAs actively interact with miRNAs in cervical cancer, leading to the regulation of diverse signaling pathways, and they can contribute to cancer hallmarks such as self-sufficiency in growth signals, insensitivity to antigrowth signals, limitless proliferation, evading apoptosis, tissue invasion and metastasis, and sustained angiogenesis. Moreover, the distinctive biomedical attributes exhibited by circRNAs, including their abundance, conservation, and stability in body fluids, position them as promising biomarkers for various cancers. In this review, we elucidate the tremendous potential of circRNAs as diagnostic markers or therapeutic targets in cervical cancer by expounding upon their biogenesis, characteristics, functions, and databases, highlighting the novel advances in the signaling pathways associated with circRNAs in cervical cancer.

RNU12 inhibits gastric cancer progression via sponging miR-575 and targeting BLID

Gastric cancer (GC) is one of the major causes of cancer deaths with 5-year survival ratio of 20%. RNU12 is one of long noncoding RNAs (lncRNAs) regulating the tumor progression. However, how RNU12 affecting GC is not clear. qRT-PCR was utilized for determining the RNU12 expression in cell lines, 113 cases of paired gastric cancer (GC) and their adjacent normal gastric tissues. The biofunction alterations of RNU12 were assessed by its overexpression or knockdown in GC cells. MTT and cloning assay were assayed for the cell proliferation, the flow cytometry for the detection of cell cycle and the wound healing assay (WHA) and transwell invasion assay (TIA) for examining the migration and invasion of cells. The expressions of a set of genes related proliferation and migration were investigated with the Western Blotting (WB). RNA immunoprecipitation (RIP), biotinylated RNA pull-down and dual luciferase reporter tests were used to detect the interactions of RNU12 with miR-575/BLID. The in vivo proliferation and migration ability of RNU12 infected cells were determined in zebrafish system. This study revealed that RNU12 inhibited proliferation, invasion and metastasis by sponging of miR-575 and regulating the downstream BLID and modulated EMT of GC cells. The RNU12/miR-575/BLID axis is likely to be the prognosis biomarkers and drug targets of GC.

A Study on the Mechanism of Action of Galangal in the Treatment of Gastric Cancer Using Network Pharmacology Technology

To study the mechanism of galangal in the treatment of gastric cancer by network pharmacology. The TCMSP database was used to collect the effective compounds and potential targets of galangal, and the genes associated with gastric cancer were obtained through the GeneCards database, and Venn obtained the interaction genes of the effective compound targets of galangal and gastric cancer targets, plotted the interaction genes into PPI networks, and screened out key targets. The interacting genes were imported into Metascape database for GO enrichment analysis and KEGG signal enrichment. A total of 13 active compounds and 207 potential downstream target genes were screened by TCMSP database. Have 5222 gastric cancer target genes through GeneCards database, there were a total of 150 interactive genes and 6 key genes: TP53, AKT1, JUN, HSP90AA1, IL6, and CASP3. These interacting genes involved 30 typical GO entries and 20 KEGG signals. Galangal may play a role in the treatment of gastric cancer by means of multi-component, multi-target and multi-signal pathway.

microRNA Expression Profiling in Young Prostate Cancer Patients

MicroRNAs (miRNAs) are small, non-coding RNA molecules with multiple roles in many biological processes. Few studies have shown the molecular characteristics in younger prostate cancer (PCa) patients. In this study, we performed miRNA profiling in young PCa (EO-PCa) cases compared with PCa arising in older men (LO-PCa). Experimental Design: Formalin-fixed, paraffin embedded tissue was used. miRNA was extracted for PCR array and NanoString methods. Relative miRNAs expression levels were obtained by comparing young vs older men, and young PCa tumor samples vs normal epithelium. Results: miRNA profiling showed a different expression pattern in PCa arising in younger men, and young PCa tumoral and its normal counterpart. Nine miRNAs (hsa-miR-140-5p, hsa-miR-146a, hsa-miR-29b, hsa-miR-9, hsa-miR-124-3p, hsa-let-7f-5p, hsa-miR-184, hsa-miR-373, hsa-miR-146b-5p) showed differences in the expression compared to LO-PCa. Fourteen miRNAs were significantly up-regulated (miR-1973, miR-663a, miR-575, miR-93-5p, miR-630, miR-600, miR-494, miR-150-5p, miR-137, miR-25-3p, miR-375, miR-489, miR-888-5p, miR-142-3p), while 9 were found down-regulated (miR-21-5p, miR-363-3p, miR-205-5p, miR-548ai, miR-3195, 145-5p, miR-143-3p, miR-222-3p, miR-221-3p) comparing young PCa tumoral tissue compared to normal counterpart. The higher expression of miR-600 and miR-137 were associated with high Gleason score, extraprostatic extension and lymphatic invasion. Conclusion: These results suggest that PCa in younger patients has a different expression profile compared to normal tissue and PCa arising in older man. Differentially expressed miRNAs provide insights of molecular mechanisms involve in this PCa subtype.

circRNA-AKT1 Sequesters miR-942-5p to Upregulate AKT1 and Promote Cervical Cancer Progression

Statistics show that the prognosis of cervical cancer (CC) is poor, and the death rate of CC in advanced stage has been rising in recent years. Increasing evidence has demonstrated that circular RNAs (circRNAs) serve as promising biomarkers in human cancers, including CC. The present study planned to find out the circRNA involved in CC and to explore its regulatory mechanism in CC. We discovered the new circRNA, circ-0033550, upregulated in CC. Its associated gene was AKT (also known as protein kinase B) serine/threonine kinase 1 (AKT1), so we renamed circ-0033550 as circ-AKT1. We confirmed the high expression of circ-AKT1 in CC samples and cell lines, as well as the circle structure of circ-AKT1. Functionally, gain- and loss-of-function experiments indicated that circ-AKT1 and AKT1 promoted CC cell proliferation and invasion. Moreover, circ-AKT1 and AKT1 were induced by transforming growth factor beta (TGF-β) and facilitated EMT (epithelial-mesenchymal transition) in CC. Mechanically, we illustrated that circ-AKT1 upregulated AKT1 by sponging miR-942-5p. Rescue assays confirmed the role of the circ-AKT1/miR-942-5p/AKT1 axis in CC progression. In vivo assays validated that circ-AKT1 promoted tumor growth in CC. Overall, circRNA-AKT1 sequestered miR-942-5p to upregulate AKT1 and promote CC progression, which may offer a new molecular target for the treatment improvement of CC.

Inhibition of TPA‑induced metastatic potential by morin hydrate in MCF‑7 human breast cancer cells via the Akt/GSK‑3β/c‑Fos signaling pathway

Plant flavonoid 2',3,4',5,7‑pentahydroxyflavone (morin hydrate), isolated from the family Moraceae (Morus alba L.), is known to have anti‑inflammatory and anticancer effects. However, its pharmaceutical effects on metastasis have not been fully elucidated to date. Therefore, the current study investigated the effects of morin hydrate on cancer metastasis in MCF‑7 human breast cancer cells. The results showed that morin hydrate suppressed 12‑O‑tetradecanoylphorbol‑13‑acetate (TPA)‑induced cell migration and invasion via the inhibition of matrix metalloproteinase (MMP)‑9 activity. Furthermore, gene expression level of MMP‑9, MMP‑7, urokinase plasminogen activator (uPA), uPA receptor (uPAR) and fibronectin were significantly decreased by morin hydrate treatment. Morin hydrate inhibited the phosphorylation of Akt and glycogen synthase kinase (GSK)‑3β, and downregulated the expression of an activator protein‑1 subunit c‑Fos. In addition, the GSK‑3β phosphorylation and c‑Fos expression were suppressed by PI3K/Akt pathway inhibitors, LY294002 and wortmannin. Taken together, these results demonstrated that morin hydrate reduced the metastatic potential in TPA‑treated MCF‑7 human breast cancer cells via the inhibition of MMPs, uPA and uPAR, and the underlying Akt/GSK‑3β/c‑Fos pathway. Therefore, the present investigation suggested that morin hydrate may be a natural substance with a preventive potential for metastasis in breast cancer cells.

Exosomal transfer of miR-501 confers doxorubicin resistance and tumorigenesis via targeting of BLID in gastric cancer

Exosomal transfer of oncogenic miRNAs can enhance recipient cell growth, metastasis and chemoresistance. Currently we found that microRNA-501-5p (miR-501) was overexpressed in doxorubicin-resistant gastric cancer (GC) SGC7901/ADR cell-secreted exosomes (ADR Exo) than that in SGC7901 cell-secreted exosomes (7901 Exo). ADR Exo was internalized by SGC7901, and a Cy3-miR-501 mimic was transferred from SGC7901/ADR to SGC7901 via exosomes. ADR Exo conferred doxorubicin resistance, proliferation, migration and invasion abilities to negative control miRNA inhibitor-expressing GC cells, whereas it inhibited apoptosis. MiR-501 knockdown or BH3-like motif-containing protein, cell death inducer (BLID) overexpression could reverse the effects of ADR Exo on recipient cells. SGC7901 cells cocultured with SGC7901/ADR prior to treatment with GW4869 or transfection of a miR-501 inhibitor were sensitive to doxorubicin and exhibited attenuated proliferation, migration and invasion and increased apoptosis. The intratumoral injection of ADR Exo into negative control miRNA inhibitor-expressing SGC7901 cells induced rapid subcutaneous tumor growth and resistance to doxorubicin compared to that of miR-501 knockdown or BLID-overexpressing cells. This effect is possibly achieved by exosomal miR-501-induced downregulation of BLID, subsequent inactivation of caspase-9/-3 and phosphorylation of Akt. Exosomal miR-501 might be a therapeutic target for GC.

LncRNA PICART1 suppressed non-small cell lung cancer cells proliferation and invasion by targeting AKT1 signaling pathway

LncRNAs play significant roles in various cell biological processes. In the present study, we demonstrated that PICART1 expression was down-regulated in non-small cell lung cancer (NSCLC) tissues. Lower expression level of PICART1 was associated with advanced stage. In addition, PICART1 expression was down-regulated in NSCLC cell lines. Overexpression of PICART1 inhibited NSCLC cell growth and induced cell cycle arrest at G2/M phase. Elevated expression of PICART1 suppressed NSCLC cell colony formation and cell invasion. Ectopic expression of PICART1 promoted the expression of epithelial marker E-cadherin while suppressed the mesenchymal marker expression such as N-cadherin and Snail and Vimentin. Furthermore, PICART1 overexpression suppressed AKT phosphorylation and c-Myc expression while inhibited the p21 expression in NSCLC cell. AKT phosphorylation was involved in PICART1 mediated suppression of cell growth and invasion. These results suggested that overexpression of PICART1 suppressed cell growth and invasion partly through regulating AKT signaling pathway in NSCLC.

MicroRNA-23a promotes colorectal cancer cell survival by targeting PDK4

MicroRNA (miR) is important regulators of gene expression, and aberrant miR expression has been linked to oncogenesis; however, little is understood about their contribution to colorectal cancer (CRC). Here, we determined that miR-23a is overexpressed in human colorectal cancer cell lines and tissues compared with that of normal cells. The stable over-expression of miR-23a in CRC cells was sufficient to promote cell proliferation in vitro and in vivo. Further studies showed that miR-23a can directly bind to the 3'untranslated region (3'UTR) of PDK4 mRNA and subsequently repress both the mRNA and protein expressions of PDK4. PDK4 negatively regulate CRC proliferation via suppressing PDH activity. Ectopic expression of PDK4 by transiently transfected with PDK4 vector encoding the entire coding sequence could reverse the effects of miR-23a on CRC proliferation. By this way, miR-23a promotes PDH activation and oxidative phosphorylation to generate sufficient ATP for cell proliferation. Our results illustrated that the up-regulation of miR-23a played an important role in CRC cell proliferation through direct repressing PDK4, suggesting a potential application of miR-23a in prognosis prediction and therapeutic application in CRC.

A Novel Mechanism of Doxorubicin Resistance and Tumorigenesis Mediated by MicroRNA-501-5p-Suppressed BLID

Doxorubicin is a widely used anthracycline-based anti-tumor agent for both solid and liquid tumors. Mounting evidence has demonstrated that microRNAs (miRNAs) are involved in chemoresistance and tumorigenesis. However, the roles of microRNA-501-5p (miR-501) in doxorubicin resistance and gastric cancer cell proliferation and invasion are still not fully understood. In this study, we identified that BLID (BH3-like motif-containing protein, cell death inducer) was directly regulated by miR-501 at the post-transcriptional level in multiple gastric cancer cell lines. Endogenous miR-501 was higher, whereas BLID was lower, in doxorubicin-resistant gastric cancer SGC7901/ADR cells compared with their parental SGC7901 cells. miR-501 suppressed gastric cancer cell apoptosis, induced resistance to doxorubicin, and enhanced cell proliferation, migration, and invasion. Subcutaneous injection of miR-501 lentivirus-infected SGC7901 cells resulted in rapid growth of xenograft tumors and resistance to doxorubicin treatment, unlike injection of negative miRNA lentivirus-infected SGC7901 cells. This is achieved at least partially by directly targeting BLID and subsequent inactivation of caspase-9 and caspase-3 and phosphorylation of Akt. Taken together, miR-501 induces doxorubicin resistance and enhances the tumorigenesis of gastric cancer cells by suppressing BLID. miR-501 might be a potential target for doxorubicin resistance and gastric cancer therapy.

Gene expression network regulated by DNA methylation and microRNA during microcystin-leucine arginine induced malignant transformation in human hepatocyte L02 cells

Microcystin (MC) is a cyclic heptapeptide compound which could lead to the development of hepatocellular carcinoma. However, the underlying epigenetic regulation mechanism is largely unknown. In this study, microcystin-LR (L: lysine, R: arginine, MC-LR) was used to induce the malignant transformation of human hepatocyte L02 cell line. The profile of gene expression, microRNA (miRNA) and DNA methylation were detected through high-throughput sequencing. Compared with control group, the expression of 826 genes and 187 miRNAs changed significantly in MC-LR treated group. DNA methylation sequencing analysis showed that 2592 CpG sites differentially methylated in promoter or the coding DNA sequence (CDS) of genes, while DNA methyltransferase 3 alpha (DNMT3a) and DNA methyltransferase 3 beta (DNMT3b) were dramatically up-regulated. Functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that significantly changed mRNAs and microRNAs were mainly involved in the formation of cancer, proliferation, invasion, migration and metabolism. MiRNA-mRNA network and mRNA-mRNA network analysis showed that hsa-miR-320a, hsa-miR-331-3p, hsa-miR-26a-5p, hsa-miR-196a-5p, hsa-miR-221-3p, coiled-coil domain containing 180 (CCDC180), melanoma antigen gene family member D1 (MAGED1), membrane spanning 4-domains A7 (MS4A7), hephaestin like 1 (HEPHL1), BH3 (Bcl-2 homology 3)-like motif containing, cell death inducer (BLID), matrix metallopeptidase 13 (MMP13), guanylate binding protein 5 (GBP5), adipogenesis regulatory factor (ADIRF), formin homology 2 domain containing 1 (FHDC1), protein kinase CAMP-dependent type II regulatory subunit beta (PRKAR2B), nodium leak channel, non-selective (NALCN), myosin light chain kinase 3 (MYLK3), epidermal growth factor receptor (EGFR) and zinc finger protein 704 (ZNF704) were key miRNAs and genes in the malignant transformation induced by MC-LR in L02 cells. Moreover, we found that expression of MYLK3, EGFR and ZNF704 were regulated by DNA methylation and miRNAs, and these genes affected the cell cycle and cell division. Our study suggested that characteristic gene alterations regulated by DNA methylation and miRNA could play an important role in environmental MC-LR induced hepatic carcinogenesis.

Tissue Stiffness and Hypoxia Modulate the Integrin-Linked Kinase ILK to Control Breast Cancer Stem-like Cells

Breast tumors are stiffer and more hypoxic than nonmalignant breast tissue. Here we report that stiff and hypoxic microenvironments promote the development of breast cancer stem-like cells (CSC) through modulation of the integrin-linked kinase ILK. Depleting ILK blocked stiffness and hypoxia-dependent acquisition of CSC marker expression and behavior, whereas ectopic expression of ILK stimulated CSC development under softer or normoxic conditions. Stiff microenvironments also promoted tumor formation and metastasis in ovo, where depleting ILK significantly abrogated the tumorigenic and metastatic potential of invasive breast cancer cells. We further found that the ILK-mediated phenotypes induced by stiff and hypoxic microenvironments are regulated by PI3K/Akt. Analysis of human breast cancer specimens revealed an association between substratum stiffness, ILK, and CSC markers, insofar as ILK and CD44 were expressed in cancer cells located in tumor regions predicted to be stiff. Our results define ILK as a key mechanotransducer in modulating breast CSC development in response to tissue mechanics and oxygen tension. Cancer Res; 76(18); 5277-87. ©2016 AACR.

BLID: A Novel Tumor-Suppressor Gene

BLID (BH3-like motif containing, cell death inducer), also known as breast cancer cell 2 (BRCC2), was first reported in the human breast cancer cell line in 2004. BLID is a BH3-like motif containing apoptotic member of the Bcl-2 family. Recently, the BLID tumor-suppressor roles have been fully established. Several studies have found that BLID is frequently downregulated in many human cancers and the downregulation is often associated with tumor progression. Multivariate analysis indicated that BLID is an independent prognostic factor for overall survival and distant metastasis-free survival. Moreover, BLID can inhibit breast cancer cell growth and metastasis and promote apoptosis. BLID can regulate the expression of various tumor-related genes and proteins, such as AKT and MMP. In this review, we provide an overview of current knowledge concerning the role of BLID in tumor development and progression. To our knowledge, this is the first review about the role of this novel tumor-suppressor gene in tumor development and progression.

miR-17-5p promotes the growth of osteosarcoma in a BRCC2-dependent mechanism

MicroRNA-17-5p has been proven upregulated in many human malignancies and correlated with tumor progression. However, its expression and clinical significance in osteosarcoma is still unclear. Thus, the aim of the present study was to explore the effects of miR-17-5p in osteosarcoma tumorigenesis and development. The expression level of miR-17-5p was quantified by quantitative real-time reverse-transcriptase-polymerase chain reaction in primary osteosarcoma tissues and osteosarcoma cell lines. MTT, Transwell and matrigel assays were used to test the proliferation, migration and invasion of miR-17-5p transfection osteosarcoma cells, and a mouse model was used to investigate tumorigenesis. The expression levels of miR-17-5p in osteosarcoma tissues were significantly higher than those in corresponding non-cancerous bone tissues. In addition, miR-17-5p upregulation more frequently occurred in osteosarcoma specimens with advanced clinical stage, positive distant metastasis and poor response to neo-adjuvant chemotherapy. After miR-17-5p transfection, cell proliferation, migration, invasion and tumorigenesis in the osteosarcoma cells were significantly promoted. We further demonstrated that BRCC2 is a direct target of miR-17-5p. These findings indicate that miR-17-5p may act not only as a novel diagnostic and prognostic marker, but also as a potential target for molecular therapy of osteosarcoma.

MicroRNA-377 suppresses cell proliferation and invasion by inhibiting TIAM1 expression in hepatocellular carcinoma

Increasing evidence has suggested that microRNAs (miRNAs) play an important role in the initiation and progression of hepatocellular carcinoma (HCC). Here, we identified a novel tumor suppressive miRNA, miR-377, and investigated its role in HCC. The expression of miR-377 in HCC tissues and cell lines was detected by real-time reverse-transcription PCR. The effects of miR-377 on HCC cell proliferation and invasion were also investigated. Western blot and luciferase reporter assay were used to identify the direct and functional target of miR-377. The expression of miR-377 was markedly downregulated in human HCC tissues and cell lines. MiR-377 can dramatically inhibit cell growth and invasion in HCC cells. Subsequent investigation revealed that T lymphoma invasion and metastasis 1 (TIAM1) was a direct and functional target of miR-377 in HCC cells. Overexpression of miR-377 impaired TIAM1-induced promotion of proliferation and invasion in HCC cells. Finally, miR-377 is inversely correlated with TIAM1 expression in human HCC tissues. These findings reveal that miR-377 functions as a tumor suppressor and inhibits the proliferation and invasion of HCC cells by targeting TIAM1, which may consequently serve as a therapeutic target for HCC patients.

MicroRNA-575 targets BLID to promote growth and invasion of non-small cell lung cancer cells

This study was designed to detect miR-575 expression and function in non-small cell lung cancer (NSCLC). A higher expression of miR-575 in NSCLC tissues was observed compared with adjacent non-neoplastic tissues. Furthermore, re-introduction of miR-575 significantly promoted cell proliferation, migration, and invasion in the NSCLC line. Moreover, we showed that BLID is negatively regulated by miR-575 at the posttranscriptional level, via a specific target site within the 3'UTR. Overexpression of BLID counteracted miR-575-induced proliferation and invasion in NSCLC cells. The expression of BLID is frequently downregulated in NSCLC tumors and cell lines and inversely correlates with miR-575 expression. The findings of this study contribute to the current understanding of the functions of miR-575 in NSCLC.

Blocking autophagy enhanced cytotoxicity induced by recombinant human arginase in triple-negative breast cancer cells

Depletion of arginine by recombinant human arginase (rhArg) has proven to be an effective cancer therapeutic approach for a variety of malignant tumors. Triple-negative breast cancers (TNBCs) lack of specific therapeutic targets, resulting in poor prognosis and limited therapeutic efficacy. To explore new therapeutic approaches for TNBC we studied the cytotoxicity of rhArg in five TNBC cells. We found that rhArg could inhibit cell growth in these five TNBC cells. Intriguingly, accumulation of autophagosomes and autophagic flux was observed in rhArg-treated MDA-MB-231 cells. Inhibition of autophagy by chloroquine (CQ), 3-methyladenine (3-MA) and siRNA targeting Beclin1 significantly enhanced rhArg-induced cytotoxic effect, indicating the cytoprotective role of autophagy in rhArg-induced cell death. In addition, N-acetyl-l-cysteine (NAC), a common antioxidant, blocked autophagy induced by rhArg, suggesting that reactive oxygen species (ROS) had an essential role in the cytotoxicity of rhArg. This study provides new insights into the molecular mechanism of autophagy involved in rhArg-induced cytotoxicity in TNBC cells. Meanwhile, our results revealed that rhArg, either alone or in combination with autophagic inhibitors, might be a potential novel therapy for the treatment of TNBC.

Aberrant BLID expression is associated with breast cancer progression

In our previous study, we have found that BH3-like motif containing, cell death inducer (BLID) was a tumor suppressor in breast cancer, and its downregulation was correlated with both poor disease-free and overall survival. In the present study, we aimed to explore the possible role of BLID in breast cancer progression. We found that BLID was strongly expressed in all normal breast tissues, and it became lower and wreaker gradually in the progression from normal, UDH (usual ductal hyperplasia), ADH (atypical ductal hyperplasia), and DCIS (ductal carcinoma in situ) to breast cancer. Statistical analysis demonstrated significant different BLID expressions between proliferative and cancerous breast lesions. Our data suggested that loss of BLID may contribute to the progression of intraductal proliferation lesions to breast cancer. Our finding gives a new clue that BLID might be a potential indicator for progression of breast cancer in the future.