Piezo1 regulates migration and invasion of breast cancer cells via modulating cell mechanobiological properties

Cell migration and invasion are two essential processes during cancer metastasis. Increasing evidence has shown that the Piezo1 channel is involved in mediating cell migration and invasion in some types of cancers. However, the role of Piezo1 in the breast cancer and its underlying mechanisms have not been clarified yet. Here, we show that Piezo1 is high-expressed in breast cancer cell (BCC) lines, despite its complex expression in clinical patient database. Piezo1 knockdown (Piezo1-KD) promotes unconfined BCC migration, but impedes confined cell migration. Piezo1 may mediate BCC migration through the balances of cell adhesion, cell stiffness, and contractility. Furthermore, Piezo1-KD inhibits BCC invasion by impairing the invadopodium formation and suppressing the expression of metalloproteinases (MMPs) as well. However, the proliferation and cell cycle of BCCs are not significantly affected by Piezo1. Our study highlights a crucial role of Piezo1 in regulating migration and invasion of BCCs, indicating Piezo1 channel might be a new prognostic and therapeutic target in BCCs.     

miR-188-5p regulates proliferation and invasion via PI3K/Akt/MMP-2/9 signaling in keloids

Keloids(KDs)and hypertrophic scars(HSs),two forms of pathological scars,seriously affect the physical and psychological health of patients.Despite many similarities with HSs,KDs are characterized by invasion and a high rate of recurrence after surgery,features they share in common with tumors.The underlying molecular mechanisms of this phenomenon have not been fully elucidated.In this study,we used microRNA(miRNA)array analysis to search for invasion-associated miRNAs in KDs.The expression of miR-188-5p in KDs,HSs,normal skin(NS)tissues,and cell lines was measured by quantitative real-time polymerase chain reaction.Furthermore,cell proliferation,migration,and invasion were detected in KD fibroblasts(KFs)and HS fibroblasts(HSFs),and interrelated proteins were ascertained by western blot analysis.It was found that miR-188-5p was significantly decreased in KD tissue compared with HS and NS tissues.Upregulated expression of miR-188-5p suppressed KF proliferation,migration,and invasion;and decreased expression of miR-188-5p also promoted HSF proliferation,migration,and invasion.The protein levels of MMP-2,MMP-9,PI3K,and p-Akt in miR-188-5p mimic-transfected KFs were repressed.In contrast,after transfection with miR-188-5p inhibitor,the protein levels of MMP-2,MMP-9,PI3K,and p-Akt were higher than the control in HSFs.Treatment with PI3K/Akt inhibitor LY294002 in KFs with miR-188-5p inhibitor did not further reduce their proliferation,migration,and invasion.The upregulation of MMP-2 and MMP-9 by miR-188-5p inhibitor could be abolished by LY294002.These findings together demonstrate a tumor-suppressive role of miR-188-5p in KD proliferation and invasion via PI3K/Akt/MMP-2/9 signaling,indicating that miR-188-5p may be a potential prognostic marker and therapeutic target for KDs.     

RNA-binding protein QKI regulates contact inhibition via Yes-associate protein in ccRCC

Contact inhibition adjusts organ size to the proper size and ensures the cultured cells growing to a monolayer.By regulating the downstream coordinator YAP,the evolutionarily conserved Hippo transduction pathway attunes cell growth and death in response to cell contact inhibition,polarity,self-renewal,and differentiation.Dysregulation of this pathway is involved in various diseases such as cancer.RNA-binding protein QKI regulates cell proliferation,metabolism,division,and immunity in various cancer models,but its role in cancer cell contact inhibition remains unclear.In this study,we aimed to clarify the relationship between QKI and YAP,and the role of their interaction in cell contact inhibition.We found a lower QKI expression level in sparse condition,whereas a higher expression level in confluent condition by western blot analysis and immunofluorescence assay.QKI knockdown elevated cell proliferation and invasion both in vitro and in vivo.Strikingly,the results of CCK-8 assay,colony formation assay,and transwell assay showed that the phenomenon was in accord with the expression level of pYAP and reverse with YAP.Higher levels of Wnt3a and β-catenin were also found in xenografts of QKI-knockdown clear cell renal cell carcinoma (ccRCC) CAKI-1 cells by western blot analysis and immumohistochemical staining.Finally,a positive correlation between QKI and pYAP was found in clinical specimens by immunohistochemistry.Thus,as a negative regulator of YAP,QKI attuned the cell contact inhibition,leading to inhibition of cancer cell proliferation and invasion through Wnt and GPCR pathway.     

miR-195-5p exerts tumor-suppressive functions in human lung cancer cells through targeting TrxR2

miR-195-5p has been widely explored in various cancers and is considered as a tumor-suppressive microRNA.However,its roles in human lung cancer pathogenesis are not fully elucidated.In this study,we aimed to explore how miR-195-5p is involved in malignant behaviors of lung adenocarcinoma(LUAD)cells.miR-195-5p expression was examined in the tumor tissues of patients with LUAD and human LUAD cell lines including A549 and PC-9.Thioredoxin reductase 2(TrxR2)was predicted to be an mRNA target of miR-195-5p using online tools and validated by the Dual-Luciferase Reporter Assay.Lentivirus infection was used for gene overexpression,while gene knockdown was achieved by RNA interference.Cell proliferation was determined by Cell Counting Kit-8 and 5-ethynyl-2′-deoxyuridine methods,and cell migration and invasion were assayed with transwell experiments.Cell apoptosis was determined by annexin V staining-based flow cytometry.The antitumor effects of miR-195-5p were also evaluated in nude mice xenografted with A549 cells.We found that miR-195-5p was lowly expressed in human LUAD cells,and its overexpression markedly suppressed cell proliferation,migration,and invasion and increased the apoptosis of LUAD cells in vitro.TrxR2 knockdown phenocopied the tumor-suppressive effects of miR-195-5p overexpression,while simultaneous TrxR2 overexpression remarkably reversed the effects of miR-195-5p overexpression on malignant behaviors of A549 and PC-9 cells.Additionally,miR-195-5p overexpression inhibited the growth of xenografted A549 tumor in nude mice.Our work verified that miR-195-5p exerts tumor-suppressive functions in LUAD cells through targeting TrxR2 and suggested that the miR-195-5p/TrxR2 axis is a potential biomarker for LUAD therapy.     

MiR-181c modulates the proliferation,migration, and invasion of neuroblastoma cells by targeting Smad7

MicroRNAs （miRNAs） function as key regulators of gene expression in various cancers. In this study, the aim is to explore the roles and regulation mechanism of miR-181c in neuroblastoma （NB） cells. We found that miR-181c was downregulated in metastatic NB tissues, compared with primary NB tissues. Then functional studies indicated that miR-181 c overexpression inhibited NB cell proliferation, migration, and invasion, while miR-181c inhibition increased cell proliferation, migration, and invasion. EGFP reporter assay, real-time polymerase chain reaction and western blot analysis validated that Smad7 was a direct target of miR- 181c. MiR-181c reduced Smad7 expression at both mRNA and protein levels. Finally, functional assays showed that the effect of Smad7 knockdown on cells was similar to that of miR-181c overexpression. Importantly, Smad7 overexpression could restore the antitumor effects that were induced by miR-181 c. In conclusion, our results demonstrated that miR- 181c inhibits NB cell growth and metastasis-related traits through the suppression of SmadT, functioning as a tumor suppressor. Moreover, our results suggested that miR-181c may serve as an important therapeutic target for NB patients.     

β-catenin is up-expressed and predicts poor overall survival of breast cancer

Breast cancer (BC) is one of the most common malignant tumors in women.The majority of BC cells contain at least one or more up-expressed oncogene. β-catenin is found overexpressed in various epithelial cell cancers and has the function of inducing cancer cell proliferation, invasion and metastasis. However, the expression of β-catenin and its prognostic value in BC is not yet clear. In this study, mRNA and β-catenin proteins expressed in BC tissues have been explored. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) on tissue microarrays (TMA) were performed to examine the level of β-catenin mRNA and protein in BC tissues. The association between β-catenin and clinical characteristics and prognostic value were also explored. β-catenin mRNA and protein were found over-expressed in BC tissues when compared with matched tumor neighbor tissues. A high degree of β-catenin staining in BC tissues was significantly associated with tumor size, Ki67 expression, lymph node status and TNM stage. β-catenin up-expression was also able to predict poor overall survival (OS) rates. These results indicated that β-catenin may be a useful prognostic molecular biomarker for BC patients.     

TRIM29 prevents hepatocellular carcinoma progression by inhibiting Wnt/β-catenin signaling pathway

TRIM29 plays an important role in many neoplasms.In this study,we aimed to elucidate its role in hepatocellular carcinoma (HCC) and explore the corresponding potential mechanism.The expression level of TRIM29 in HCC samples and hepatoma cell lines was detected.We found that TRIM29 was down-regulated in clinical HCC samples and cultured hepatoma cell lines by western blot analysis and quantitative polymerase chain reaction.In addition,we demonstrated that higher TRIM29 expression was associated with higher differentiation grade of HCC.To explore the effect of TRIM29 on hepatoma cells and its possible mechanisms,TRIM29-knockdown and overexpression cell models were constructed.The results showed that the depletion of TRIM29 promoted liver cancer cell proliferation,clone formation,migration and invasion in vitro probably through the Wnt/β-catenin signaling pathway.This study revealed the inhibitory roles of TRIM29 in HCC and the possible mechanisms.     

ARRB2 promotes colorectal cancer growth through triggering WTAP

Colorectal cancer (CRC) is one of the most lethal cancers worldwide. The expression of β-arrestin2 (β-Arr2, ARRB2) in CRC has been well investigated;however, its exact mechanism causing the cancer progression remains unclear. In this study, we discovered that the expression level of ARRB2 was significantly upregulated in CRC as compared to the normal tissues by employing the Cancer Genome Atlas (TCGA) data, western blot analysis, and immunohistochemistry. Furthermore, the level of ARRB2 was correlated with the patients’ overall survival by Kaplan–Meier analysis. The higher expression of ARRB2 promoted CRC cell growth, enhanced the cell motility, and blocked cell apoptosis, which is crucial for tumor growth. Lastly, the suppression of ARRB2 expression was enough to attenuate the progression of CRC induced by azoxymethane/dextran sodium sulfate. Interestingly, we also found that the knockdown of ARRB2 decreased several cancer pathways mediated by the expression of Wilms tumor 1 associated protein (WTAP), which led to the inhibition of cell proliferation and migration. Altogether, our results demonstrated that ARRB2 promoted the growth and migration of CRC cells by regulating the WTAP expression.     

Cortactin is involved in transforming growth factor-β1-induced epithelial-mesenchymal transition in AML-12 cells

Cortactin is an F-actin binding protein, regulating cell movement and adhesive junction assembly. However, the function of cortactin in epithelial-mesenchymal transition （EMT） remains elusive. Here we found that during transforming growth factor-β1 （TGF-β1）- induced EMT in AML-12 murine hepatocytes, cortactin underwent tyrosine dephosphorylation. Inhibition of the dephosphorylation of eortactin by sodium vanadate blocked TGF-β1-induced EMT. Knockdown of cortactin by RNAi led to decrease of intercellular junction proteins E-cadherin and Zonula occludens-1 and induced expression of mesenchymal protein fibronectin. Additionally, knockdown of cortactin further promoted TGF-β1-induced EMT in AML-12 cells, as determined by EMT markers and cell morphological changes. Moreover, migration assay showed that cortactin knockdown promoted the migration of AML-12 cells, and also enhanced TGF-β1-induced migration. Our study showed the involvement of cortactin in the TGF- β1-induced EMT.     

Fucoxanthin induces growth arrest and apoptosis in human bladder cancer T24 cells by up-regulation of p21 and down-regulation of mortalin

Fucoxanthin, a natural carotenoid, has been reported to have anti-cancer activity in human colon cancer cells, human prostate cancer cells, human leukemia cells, and human epithelial cervical cancer cells. This study was undertaken to evaluate the molecular mechanisms of fuco- xanthin against human bladder cancer T24 cell line. MTT analysis results showed that 5 and 10 ixM fucoxanthin inhibited the proliferation of T24 cells in a dose- and time- dependent manner accompanied by the growth arrest at Go/G1 phase of cell cycle, which is mediated by the up-regu- lation of p21, a cyclin-dependent kinase （CDK）-inhibitory protein and the down-regulation of CDK-2, CDK-4, cyclin D1, and cyclin E. In addition, 20 and 40 μM fucoxanthin induced apoptosis of T24 cells by the abrogation of morta- lin-p53 complex and the reactivation of nuclear mutant- type p53, which also had tumor suppressor function as wild-type p53. All these results demonstrated that the anti- cancer activity of fucoxanthin on T24 cells was associated with cell cycle arrest at Go/G1 phase by up-regulation of p21 at low doses and apoptosis via decrease in the expres- sion level of mortalin, which is a stress regulator and a mem- ber of heat shock protein 70, followed by up-regulation of cleaved caspase-3 at high doses.     

CEACAM6 promotes tumor migration,invasion, and metastasis in gastric cancer

Carcinoembryonic antigen-related cell adhesion molecule 6 （CEACAM6） shows increased expression in a wide variety of human cancers, and its over-expression is associated with enhanced migration, invasion, and in vivo metastasis. Here, we reported that CEACAM6 was up-regulated in gastric cancer （GC） cell lines and tumor tissues. Overexpression of CEACAM6 in MKN-45 and SGC-7901 GC cells promoted migration and invasion in vitro and metastasis in athymic mice, whereas migration and invasion of MKN-28 and SNU-16 GC cells were suppressed by knockdown of CEACAM6. We also observed that steroid receptor coactivator （C-SRC） phosphorylation was increased when CEACAM6 was over-expressed in SGC-7901 cells. Taken together, these results suggested that CEACAM6 functions as an oncoprotein in GC and may be an important metastatic biomarker and therapeutic target.     

Proliferation inhibition and apoptosis promotion by dual silencing of VEGF and Survivin in human osteosarcoma

Simultaneous silencing of multiple upregulated genes is an attractive and viable treatment strat-egy for many incurable diseases including cancer.Herein we used a dual gene-targeted siRNA conjugate composed of VEGF and Survivin siRNA sequences in the same backbone to inhibit proliferation and angiogenesis in two human osteosarcoma cell lines.We synthesized siRNA sequences targeting the VEGF and Survivin genes individually (VEGF siRNA and Survivin siRNA) or simultaneously (one-chain-double-target siRNA:dual siRNA).VEGF and Survivin mRNA and protein expression levels in human osteosarcoma MG-63 and Saos-2 cells were detected by qRT- PCR and western blot analysis.VEGF and Survivin protein location and expression were evaluated by immunohistochemistry and immunofluorescence staining.MG-63 and Saos-2 cell migration,proliferation,apoptosis,and angiogenesis were detected by scratch test,MTT assay,flow cytometry,and capillary tube assay respectively.The dual siRNA induced similar downregulation of VEGF and Survivin mRNA and protein levels,compared with VEGF siRNA or Survivin siRNA alone.The dual siRNA caused greater suppression of MG-63 and Saos-2 cell migration,proliferation and angiogenesis,and promoted more cell apoptosis than VEGF siRNA or Survivin siRNA alone,suggesting that the effects of the dual siRNA on inhibiting cell proliferation,migration,and angiogenesis and promoting apoptosis were superior to those of the single-target siRNAs.Simultaneous silencing of VEGF and Survivin using the dual siRNA may be an advantageous alternative for the development of therapeutic strategies against human osteosarcoma.     

Profiling of differentially expressed genes in LRRC4 overexpressed glioblastoma cells by cDNA array

Our previous study has shown that LRRC4 is a novel member of the leucine-rich repeat （LRR） superfamily and has the potential to suppress brain tumor growth. In order to further analyze the functions of LRRC4 on the maintenance of normal function and suppression of tumorigenesis in the central nervous system, we investigated alterations in gene expression related to neurobiology by the Atlas array in two inducible dual-stable LRRC4-overexpressing cell lines. Seventeen of 588 genes spotted on the Atlas membrane showed altered expression levels in LRRC4 transfected U251MG Tet-on cells, which are involved in cell proliferation and cell cycle progression, tumor invasion and metastasis, and neurotransmitter synthesis and release. In addition, cell invasion assay results showed that LRRC4 can inhibit the U251MG cell migration. These studies represent the first cDNA array analysis of the effects of LRRC4 on the involvement of different neurobiological genes in U251MG glioblastoma cells and provide new insights into the function of LRRC4 in glioma.