Polystyrene Nanoplastics Activate Autophagy and Suppress Trophoblast Cell Migration/Invasion and Migrasome Formation to Induce Miscarriage

Nanoplastics (NPs), as emerging pollutants, have attracted global attention. Nevertheless, the adverse effects of NPs on female reproductive health, especially unexplained miscarriage, are poorly understood. Defects of trophoblast cell migration and invasion are associated with miscarriage. Migrasomes were identified as cellular organelles with largely unidentified functions. Whether NPs might affect migration, invasion, and migrasome formation and induce miscarriage has been completely unexplored. In this study, we selected polystyrene nanoplastics (PS-NPs, 50 nm) as a model of plastic particles and treated human trophoblast cells and pregnant mice with PS-NPs at doses near the actual environmental exposure doses of plastic particles in humans. We found that exposure to PS-NPs induced a pregnant mouse miscarriage. PS-NPs suppressed ROCK1-mediated migration/invasion and migrasome formation. SOX2 was identified as the transcription factor of ROCK1. PS-NPs activated autophagy and promoted the autophagy degradation of SOX2, thus suppressing SOX2-mediated ROCK1 transcription. Supplementing with murine SOX2 or ROCK1 could efficiently rescue migration/invasion and migrasome formation and alleviate miscarriage. Analysis of the protein levels of SOX2, ROCK1, TSPAN4, NDST1, P62, and LC-3BII/I in PS-NP-exposed trophoblast cells, villous tissues of unexplained miscarriage patients, and placental tissues of PS-NP-exposed mice gave consistent results. Collectively, this study revealed the reproductive toxicity of nanoplastics and their potential regulatory mechanism, indicating that NP exposure is a risk factor for female reproductive health.

Protumorigenic role of the atypical cadherin FAT1 by the suppression of PDCD10 via RelA/miR221-3p/222-3p axis in glioblastoma

The atypical cadherin FAT1 function either as a pro or antitumorigenic in tumors of different tissue origins. Our group previously demonstrated the protumorigenic nature of FAT1 signaling in glioblastoma (GBM). In this study, we investigated how FAT1 influences the expression of clustered oncomiRs (miR-221-3p/miR-222-3p) and their downstream effects in GBM. Through several experiments involving the measurement of specific gene/microRNA expression, gene knockdowns, protein and cellular assays, we have demonstrated a novel oncogenic signaling pathway mediated by FAT1 in glioma. These results have been verified using antimiRs and miR-mimic assays. Initially, in glioma-derived cell lines (U87MG and LN229), we observed FAT1 as a novel up-regulator of the transcription factor NFκB-RelA. RelA then promotes the expression of the clustered-oncomiRs, miR-221-3p/miR-222-3p, which in turn suppresses the expression of the tumor suppressor gene (TSG), PDCD10 (Programmed cell death protein10). The suppression of PDCD10, and other known TSG targets (PTEN/PUMA), by miR-221-3p/miR-222-3p, leads to increased clonogenicity, migration, and invasion of glioma cells. Consistent with our in-vitro findings, we observed a positive expression correlation of FAT1 and miR-221-3p, and an inverse correlation of FAT1 and the miR-targets (PDCD10/PTEN/PUMA), in GBM tissue-samples. These findings were also supported by publicly available GBM databases (The Cancer Genome Atlas [TCGA] and The Repository of Molecular Brain Neoplasia Data [Rembrandt]). Patients with tumors displaying high levels of FAT1 and miR-221-3p expression (50% and 65% respectively) experienced shorter overall survival. Similar results were observed in the TCGA-GBM database. Thus, our findings show a novel FAT1/RelA/miR-221/miR-222 oncogenic-effector pathway that downregulates the TSG, PDCD10, in GBM, which could be targeted therapeutically in a specific manner.

Partial acquisition of stemness properties in tumorspheres obtained from interleukin-8-treated MCF-7 cells

The interleukin-8 is an important regulator of the tumor microenvironment, promoting the epithelial-mesenchymal transition and the acquisition of stem-like cell properties in cancer cells. The tumorsphere-formation assay has been used for the identification of cancer stem cell. Interleukin-8 induces the formation of larger tumorspheres in Michigan Cancer Foundation-7 (MCF-7) cells, suggesting cancer stem cell enrichment. In this work, we aimed to study the phenotypic and functional characteristics of the cells present within the tumorspheres of MCF-7 cells previously treated with interleukin-8. MCF-7 cells treated for 5 days or not with this cytokine were further cultivated in ultralow attachment plates for another 5 days to allow tumorspheres formation. We showed that the enhanced sphere formation by MCF-7 cells was not a consequence of higher cell proliferation by interleukin-8 stimulation. Despite maintaining an epithelial-mesenchymal transition phenotype with the presence of epithelial and mesenchymal markers, basic stemness properties were impaired in tumorspheres and in those treated with interleukin-8, while others were increased. Self-renewal capacity was increased in interleukin-8-treated cells only in the first generation of tumorspheres but was not sustained in consecutive assays. Accordingly, self-renewal and reprogramming gene expression, differentiation capacity to adipocytes, and clonogenicity were also impaired. We showed also that tumorspheres were enriched in differentiated luminal cells (EpCAM+/CD49f-). Nevertheless, cells were more quiescent and maintain a partial epithelial-mesenchymal transition, consistent with their increased resistance to Paclitaxel and Doxorubicin. They also presented higher migration and interleukin-8-directed invasion. Therefore, the breast cancer cell line MCF-7, having a low stemness index, might partially acquire some stem-like cell attributes after interleukin-8 stimulation, increasing its aggressiveness.

Knockdown of TMPRSS3 inhibits cell proliferation, migration/invasion and induces apoptosis of glioma cells

Transmembrane protease serine 3 (TMPRSS3) is a member of type II transmembrane serine proteases (TTSP) family, which play important roles in the development and progression of various cancers. However, the role of TMPRSS3 in glioma remains unclear. In the present study, we evaluated the expression patterns of TMPRSS3 in clinical tumor samples and glioma cell lines. The results showed that TMPRSS3 was highly expressed in both human glioma tissues and cell lines. Knockdown of TMPRSS3 in glioma cells by transfection with small interfering RNA targeting TMPRSS3 (si-TMPRSS3) significantly suppressed cell proliferation and migration/invasion. Moreover, knockdown of TMPRSS3 markedly elevated the apoptotic rate of glioma cells. Si-TMPRSS3 transfection also resulted in a remarkable increase in bax expression and a notable decrease in bcl-2 expression in glioma cells. Furthermore, TMPRSS3 knockdown markedly suppressed the expressions of Notch1 and Hes1. The results indicated that knockdown of TMPRSS3 exhibited antiglioma effect, which is associated with the inactivation of the Notch signaling pathway. These findings suggested that TMPRSS3 might be used as a therapeutic target for glioma treatment.

Hematopoietic lineage cell-specific protein 1 (HS1), a hidden player in migration, invasion, and tumor formation, is over-expressed in ovarian carcinoma cells

Hematopoietic lineage cell-specific protein 1 (HS1), which is the hematopoietic homolog of cortactin, is an actin-binding protein and Lyn substrate. It is upregulated in several cancers and its expression level is associated with increased cell migration, metastasis, and poor prognosis. Here we investigated the expression and roles of HS1 in ovarian carcinoma cells. We analyzed the expression of HS1 in 171 ovarian cancer specimens and determined the association between HS1 expression and clinicopathological characteristics, including patient outcomes. In patients with stage II-IV disease, positive HS1 expression was associated with significantly worse overall survival than negative expression (P < 0.05). HS1 was localized in invadopodia in some ovarian cancer cells and was required for invadopodia formation. Migration and invasion of ovarian cancer cells were suppressed by down-regulation of HS1, but increased in cells that over-expressed exogenous HS1. Furthermore, ovarian cancer cells that expressed HS1 shRNA exhibited reduced tumor formation in a mouse xenograft model. Finally, we found that tyrosine phosphorylation of HS1 was essential for cell migration and invasion. These findings show that HS1 is a useful biomarker for the prognosis of patients with ovarian carcinoma and is a critical regulator of cytoskeleton remodeling involved in cell migration and invasion.

Serum containing Buyang Huanwu decoction prevents age-associated migration and invasion of human vascular smooth muscle cells by up regulating SIRT1 expression

The migration and invasion of vascular smooth muscle cells (VSMCs) caused by advanced aging play an important role in diffuse intimal thickening, facilitate adverse arterial remodeling and contribute to the initiation and progression of cardiovascular diseases. The inhibitory function of Buyang Huanwu decoction (BYHWD) has been found on aortic intimal hyperplasia and VSMC proliferation, but its effect on age-associated migration and invasion remains unknown. Here, we used an in vitro angiotensin II (Ang II)-induced senescence model to study the effects of serum containing BYHWD (BYHWS) on the migratory and invasive capacities, matrix metalloprotease type 2 (MMP-2) expression and modulation of sirtuin1 (SIRT1) signaling in human aorta VSMCs (HA-VAMCs). Our results showed that BYHWS was able to inhibit Ang II-induced migration and invasion, with down-regulation of MMP-2. In addition, manipulation of SIRT1 by either over-expression or siRNA knockdown ameliorated or promoted cellular migration and invasion, respectively. Moreover, BYHWS reversed senescence-mediated decrease of SIRT1 levels and SIRT1 was required for BYHWS regulation on migration and invasion of senescent HA-VAMCs. In summary, our data demonstrated that BYHWS suppressed the migration and invasion of age-associated VSMC via an increase of the SIRT1 level, which provides novel insights for the therapy of age-associated cardiovascular diseases.

The role of SH3GL3 in myeloma cell migration/invasion, stemness and chemo-resistance

Multiple myeloma (MM) is an incurable cancer characterized by clonal expansion of malignant plasma cells in the bone marrow and their egress into peripheral blood. The mechanisms of myeloma cells migration/invasion have remained unclear. Herein, we found SH3GL3 was highly expressed in the CD138-negative (CD138⁻) myeloma cells. The migration/invasion capability of CD138⁻ cells was significantly higher than that in the CD138-positive (CD138⁺) cells. Silencing SH3GL3 using shRNA reduced myeloma cells migration/invasion. Conversely, overexpression of SH3GL3 increased myeloma cells migration/invasion. Moreover, SH3GL3 is also associated with the stemness and chemo-resistance of CD138⁻ myeloma cells. Elevated expression of stem cell and multi-drug resistant markers were seen in the myeloma cells with overexpressed SH3GL3; while knocking-down SH3GL3 reduced the expression of these markers. A marked increase in p-PI3K and p-FAK was observed in the cells with overexpressed SH3GL3. To test if FAK/PI3K signaling pathway was involved in the SH3GL3-mediated myeloma cells migration, the cells transfected w/wo SH3GL3 cDNA were treated with FAK inhibitor 14 and PI3K inhibitor LY294002. Inhibition of FAK and PI3K attenuated SH3GL3-mediated migration /invasion. Our findings indicate that SH3GL3 plays an important role in myeloma cell migration/invasion, stemness and chemo-resistance. The SH3GL3-mediated myeloma cell migration/invasion is mediated by FAK/PI3K signaling pathway.

T-type calcium channels drive migration/invasion in BRAFV600E melanoma cells through Snail1

Melanoma is a malignant tumor derived from melanocytes. Once disseminated, it is usually highly resistant to chemotherapy and is associated with poor prognosis. We have recently reported that T-type calcium channels (TTCCs) are overexpressed in melanoma cells and play an important role in melanoma progression. Importantly, TTCC pharmacological blockers reduce proliferation and deregulate autophagy leading to apoptosis. Here, we analyze the role of autophagy during migration/invasion of melanoma cells. TTCC Cav3.1 and LC3-II proteins are highly expressed in BRAFV600E compared with NRAS mutant melanomas, both in cell lines and biopsies. Chloroquine, pharmacological blockade, or gene silencing of TTCCs inhibit the autophagic flux and impair the migration and invasion capabilities, specifically in BRAFV600E melanoma cells. Snail1 plays an important role in motility and invasion of melanoma cells. We show that Snail1 is strongly expressed in BRAFV600E melanoma cells and patient biopsies, and its expression decreases when autophagy is blocked. These results demonstrate a role of Snail1 during BRAFV600E melanoma progression and strongly suggest that targeting macroautophagy and, particularly TTCCs, might be a good therapeutic strategy to inhibit metastasis of the most common melanoma type (BRAFV600E).

Activation of KLF4 expression by small activating RNA promotes migration and invasion in colorectal epithelial cells

RNA activation mediated by small double-stranded RNAs targeting promoter sequence named small activating RNAs (saRNAs) is one of the mechanisms for gene activation. Artificial regulation of gene expression through RNA activation does not affect the alteration of the genomic DNA sequences or exogenous plasmid DNA, therefore it is a relative manageable approach for gene perturbation. KLF4 is a member of zinc-finger transcription factors and its functions in colorectal cells are still controversial. In order to elucidate the functions of KLF4, we synthesized saRNAs that target the promoter regions of KLF4 and transfected into varied colorectal epithelial cell lines. We found the KLF4 gene expression is specifically increased in the human normal epithelial cell NCM460 and colorectal epithelial cancer cell Caco-2 and HCT116, but not in other human colorectal epithelial cell lines. In addition, we observed that saRNAs induced overexpression of KLF4 could promote cell migration/invasion in NCM460 and HCT116 cell lines. This effect is mediated partly by inducing EMT and facilitating nuclear translocation of β-catenin.

The metastasis suppressor CD82/KAI1 regulates cell migration and invasion via inhibiting TGF-β 1/Smad signaling in renal cell carcinoma

The tetraspanin KAI1/CD82 was identified as a tumor metastasis suppressor that downregulated in various malignant cell types. However, the function of CD82 and its underlying anti-metastasis role in renal cell carcinoma (RCC) is still unraveled. Here, we investigated the expression of CD82 in RCC and explored its regulatory mechanism in RCC cell lines. We found that CD82 was down-regulated in RCC tissues and cells and its expression was significantly associated with histological grade(p=0.041), tumour stage (p=0.036) and tumor size(p=0.020) by analyzing tissue microarrays. After upregulation of CD82 through lentivirus, reduced ability of migration and invasion in Caki-1 cells were detected. In contrast, gene silencing of CD82 by small interfering RNA promoted metastatic and invasive potential of 786-O cells. Furthermore, Western blot was performed to identify the influence of CD82 on MMP family and TGF-β1/Smad pathway in RCC. Subsequently, upregulating protein level of TGF-β1 with the overexpression of CD82 could rescue the malignant behaviors inhibited by CD82 which indicated that CD82 played its inhibitory role in RCC partially by attenuating the expression of TGF-β1. Taken together, CD82 played a prominent role in migration and invasion of RCC cells and it might exhibit its inhibitory role in RCC metastasis via block TGF-β1/Smad signaling pathway.

The long non-coding RNA MALAT1 promotes the migration and invasion of hepatocellular carcinoma by sponging miR-204 and releasing SIRT1

Increasing evidence supports the significance of long non-coding RNA in cancer development. Several recent studies suggest the oncogenic activity of long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in hepatocellular carcinoma. In this study, we explored the molecular mechanisms by which MALAT1 modulates hepatocellular carcinoma biological behaviors. We found that microRNA-204 was significantly downregulated in sh-MALAT1 HepG2 cell and 15 hepatocellular carcinoma tissues by quantitative real-time polymerase chain reaction analysis. Through bioinformatic screening, luciferase reporter assay, RNA-binding protein immunoprecipitation, and RNA pull-down assay, we identified microRNA-204 as a potential interacting partner for MALAT1. Functionally, wound-healing and transwell assays revealed that microRNA-204 significantly inhibited the migration and invasion of hepatocellular carcinoma cells. Notably, sirtuin 1 was recognized as a direct downstream target of microRNA-204 in HepG2 cells. Moreover, si-SIRT1 significantly inhibited cell invasion and migration process. These data elucidated, by sponging and competitive binding to microRNA-204, MALAT1 releases the suppression on sirtuin 1, which in turn promotes hepatocellular carcinoma migration and invasion. This study reveals a novel mechanism by which MALAT1 stimulates hepatocellular carcinoma progression and justifies targeting metastasis-associated lung adenocarcinoma transcript 1 as a potential therapy for hepatocellular carcinoma.

Long non-coding RNA TUG1 promotes migration and invasion by acting as a ceRNA of miR-335-5p in osteosarcoma cells

Long non-coding RNA (lncRNA) have been the focus of increasing attention due to the role they play in many diseases, including osteosarcoma. The function of taurine upregulated gene 1 (TUG1) and its mechanism in osteosarcoma remain unclear. In our research, we found that TUG1 was elevated and correlated with a poor prognosis in osteosarcoma patients. In addition, the following functional experiment showed that decreased TUG1 could remarkably inhibit osteosarcoma cell migration and invasion, indicating that TUG1 functioned as an oncogene in osteosarcoma. Moreover, we revealed that TUG1 and Rho-associated coiled-coil-containing protein kinase 1 (ROCK1), a metastasis-related gene targeted by microRNA-335-5p (miR-335-5p), had the same miR-335-5p combining site. The subsequent luciferase assay verified TUG1 was a target of miR-335-5p. Furthermore, the results of a real-time quantitative PCR showed that TUG1 and miR-335-5p could affect each other's expression. respectively. Finally, we affirmed that TUG1 affected ROCK1 expression and ROCK1-mediated migration/invasion by working as a competitive endogenous RNA (ceRNA) via miR-335-5p. In summary, the findings of this study, based on ceRNA theory, combining the research foundation of miR-335-5p and ROCK1, and taking TUG1 as a new study point, provide new insight into molecular-level reversing migration and invasion of osteosarcoma.

Focal adhesion kinases crucially regulate TGFβ-induced migration and invasion of bladder cancer cells via Src kinase and E-cadherin

Focal adhesion kinase (FAK) is a non-receptor protein-tyrosine kinase that is triggered off by special extracellular signals such as some growth factors and integrins. FAK is found in cell-matrix attachment sites and implicated in cell migration, invasion, movement, gene expression, survival and apoptosis. In this study, we aimed to investigate whether FAK plays a role in invasion and migration of bladder cancer cells. Using an FAK-specific small interfering RNA (siRNA) and an FAK inhibitor PF-228, we found that inhibition of FAK tyrosine phosphorylation or knockdown of FAK suppressed invasion and migration of bladder cancer cells. Src is an important mediator of FAK-regulated migratory and invasive activity. Tyrosine phosphorylation of Src and FAK is mutually dependent and plays a key role in transforming growth factor beta (TGFβ)-induced invasion and migration. E-cadherin acts downstream of FAK and is a critical negative regulator in FAK-regulated invasion and migration of bladder cancer cells. These findings imply that FAK is involved in oncogenic signaling of invasion and migration, which can be a novel therapeutic target to treat patients with bladder cancer.

Expression of uPAR in human trophoblast and its role in trophoblast invasion

Placental trophoblast cells differentiate into invasive trophoblasts or syncytiotrophoblasts. Abnormal trophoblast invasion results in pregnancy-associated disease and abortion. uPAR is a cell membrane-bound glycosylated protein, involved in physiological and pathological processes. However, uPAR expression in villi during threatened abortion and its role in trophoblast differentiation are unclear. We determined that, uPAR expression in the villi was reduced in threatened abortion patients than that in normal pregnancy. uPARsiRNA inhibited the potential for trophoblast migration and invasion in explants culture and HTR8/SVneo cells. It also enhanced forskolin-induced fusion of HTR8/SVneo cells. Overall, this study provides a possible reason for abortion.

Induction of the mesenchymal to epithelial transition by demethylation- activated microRNA-200c is involved in the anti-migration/invasion effects of arsenic trioxide on human breast cancer cells

Breast cancer is a major health problem worldwide. Current standard practices for treatment of breast cancer are less than satisfactory because of high rates of metastasis. Arsenic trioxide (As(2)O(3)), which induces demethylation of DNA and causes apoptosis, has been used as an anti-tumor agent. Little is known, however, regarding its anti-metastatic effects. The microRNA-200c (miR-200c), which is frequently lowly expressed in triple negative breast cancers (TNBCs), inhibits metastasis by inducing the mesenchymal to epithelial transition (MET). Here, we report that As(2)O(3) attenuates the migratory and invasive capacities of breast cancer cells, MDA-MB-231 and BT-549. Notably, As(2)O(3) induces an MET in vitro and in vivo, as determined by the increased expression of the epithelial marker, E-cadherin and decreased expressions of mesenchymal markers, N-cadherin and vimentin. Moreover, As(2)O(3) up-regulates the expression of miR-200c through demethylation. Over-expression of miR-200c enhances the expression of E-cadherin and decreases the expressions of N-cadherin and vimentin. Further, in MDA-MB-231 cells exposed to As(2)O(3), knockdown of miR-200c blocks the As(2)O(3) -induced MET. Finally, in MDA-MB-231 and BT-549 cells exposed to As(2)O(3), knockdown of miR-200c decreases the As(2)O(3) -induced inhibition of the migratory and invasive capacities. By identifying a mechanism whereby As(2)O(3) regulates miR-200c and MET, the results establish the anti-migration/invasion potential of arsenic trioxide.