PRR11 Overexpression Facilitates Ovarian Carcinoma Cell Proliferation, Migration, and Invasion Through Activation of the PI3K/AKT/β-Catenin Pathway

BACKGROUND/AIMS

Ovarian cancer (OC) is the most lethal gynecologic malignancy, mainly due to the advanced stage at diagnosis in most patients and high rate of relapse. Thus, it is still essential to elucidate the underlying mechanisms and explore the diagnostic and therapeutic targets of OC. Recent studies have revealed that proline-rich protein 11 (PRR11) is dysregulated in different cancers, participating in their initiation and progression; however, it remains unclear whether PRR11 is involved in OC.

METHODS

Immunohistochemical staining, quantitative reverse transcription PCR, and western blotting were performed to evaluate PRR11 expression in OC tissues and cells. The relationship between PRR11 expression and the clinicopathologic data of patients were analyzed. We upregulated and downregulated PRR11 expression using a PRR11 overexpression vector and PRR11-specifc small interfering RNA, respectively, to further clarify its role in the malignant biological behavior of OC in vitro.

RESULTS

Overexpression of PRR11 in OC tissues and cells significantly correlated with advanced FIGO stage, lymph node metastasis, and large tumor size. Downregulation of PRR11 inhibited cell proliferation and prevented the invasion and migration of HO-8910 OC cells, whereas opposite results were observed in Caov3 cells upon PRR11 upregulation. Further analyses showed that PRR11 positively regulated cell proliferation-related proteins, including c-myc and cyclin D1, and increased and decreased the expression of matrix metalloproteinase 2 and tissue inhibitor of metalloproteinase 2, respectively. Additionally, our preliminary results demonstrated that PRR11 expression was mediated by the phosphoinositide 3-kinase/AKT/β-catenin signaling pathway.

CONCLUSION

The results of this study provide evidence that PRR11 plays a critical role in the progression and metastasis of OC, and as such, may serve as a potential prognostic and therapeutic target in OC.

Melatonin inhibits 17β-estradiol-induced migration, invasion and epithelial-mesenchymal transition in normal and endometriotic endometrial epithelial cells

BACKGROUND

Melatonin is a potential therapeutic agent for endometriosis, but its molecular mechanism is unclear. Here, we investigated the effect of melatonin on the epithelial-mesenchymal transition (EMT) in endometriotic endometrial epithelial cells and explored the pathway that might be involved.

METHODS

This hospital-based study included 60 women of reproductive age using the endometrium for immunohistochemistry, 6 women of reproductive age undergoing bilateral tubal ligation and 6 patients with endometriosis for isolation of endometrial epithelial cells or subsequent analysis, respectively. We examined the expression of Notch1/Numb signaling and EMT markers by immunohistochemistry analysis and western blot analysis, the invasion and migration of endometrial epithelial cells by transwell assays, and the cell proliferation by CCK8 assays.

RESULTS

Compared with normal endometrium, the endometriotic eutopic endometrium showed increased expression of Notch1, Slug, Snail, and N-cadherin, and decreased expression of E-cadherin and Numb. Melatonin or Notch inhibition by specific inhibitor blocked 17β-estradiol-induced cell proliferation, invasion, migration and EMT-related markers in both normal and endometriotic epithelial cells.

CONCLUSIONS

Our data suggest that aberrant expression of Notch1/Numb signaling and the EMT is present in endometriotic endometrium. Melatonin may block 17β-estradiol-induced migration, invasion and EMT in normal and endometriotic epithelial cells by upregulating Numb expression and decreasing the activity of the Notch signaling pathway.

ITGBL1 promotes migration, invasion and predicts a poor prognosis in colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies worldwide; its progression and prognosis are associated with oncogenes. The present study aimed to identify differentially expressed genes (DEGs) and explore the role and potential mechanism of integrin subunit β like 1 (ITGBL1) in CRC. The microarray dataset GSE41258 was used to screen DEGs involved in CRC. Survival analysis was performed to predict the prognosis of CRC patients. To validate ITGBL1 expression, immunohistochemistry, quantitative real-time PCR and western blotting were performed in CRC tissues and cells. Subsequently, the effects of ITGBL1 were evaluated through colony formation, cell proliferation, migration and invasion assays. Finally, we took advantage of Gene Ontology (GO) analysis and Gene Set Enrichment Analysis (GSEA) to explore potential function and mechanism of ITGBL1 in CRC. In our study, 182 primary CRC tissues and 54 normal colon tissues were contained in GSE41258 dataset. A total of 318 DEGs were screened, among which ITGBL1 was found to be significantly up-regulated in CRC, and its high expression was associated with shortened survival of CRC patients. Moreover, knockdown of ITGBL1 promoted CRC cell proliferation, migration and invasion. Finally, GO analysis revealed that ITGBL1 was associated with cell adhesion. GSEA indicated that ITGBL1 was enriched in ECM receptor interaction and focal adhesion. In conclusion, a novel oncogene ITGBL1 was identified and demonstrated to be associated with the progression and prognosis of CRC, which might be a potential therapeutic target and prognostic biomarker for CRC patients.

Perfluorooctanoic acid stimulates ovarian cancer cell migration, invasion via ERK/NF-κB/MMP-2/-9 pathway

As widely used in consumer products, perfluorooctanoic acid (PFOA) has become a common environmental pollutant, which has been detected in human serum and associated with cancers. Our previous study showed that PFOA is a carcinogen that promotes endometrial cancer cell migration and invasion through activation of ERK/mTOR signaling. Here, we showed that PFOA (≥100 nM) treatment also stimulated A2780 ovarian cancer cell invasion and migration, which correlated with increased matrix metalloproteinases MMP-2/-9 expression, important proteases associated with tumor invasion and migration. Notably, PFOA treatment induced activation of ERK1/2/ NF-κB signaling. Pre-treatment with U0126, an ERK1/2inhibitor；or JSH-23, a NF-kB inhibitor, can reverse the PFOA-induced cell migration and invasion. Consistent with these results, inhibiting ERK1/2 or NF-κB signaling abolished PFOA-induced up-regulation of MMP-2/-9 expression. These results indicate that PFOA can stimulate ovarian cancer cell migration, invasion and MMP-2/-9 expression by up-regulating ERK/NF-κB pathway.

AKT2 contributes to increase ovarian cancer cell migration and invasion through the AKT2-PKM2-STAT3/NF-κB axis

Multiple studies have shown that protein kinase Bβ (AKT2) is involved in the development and progression of ovarian cancer, however, its precise role remains unclear. Here we explored the underlying molecular mechanisms how AKT2 promotes ovarian cancer progression. We examined the effects of AKT2 in vitro in two ovarian cancer cell lines (SKOV3 and HEY), and in vivo by metastasis assay in nude mice. The migration and invasion ability of SKOV3 and HEY cells was determined by transwell assay. Overexpression and knockdown (with shRNA) experiments were carried out to unravel the underlying signaling mechanisms induced by AKT2. Overexpression of AKT2 led to increased expression of pyruvate kinase (PKM2) in ovarian cancer cells and in lung metastatic foci from nude mice. Elevated AKT2/PKM2 expression induced cell migration and invasion in vitro, as well as lung metastasis in vivo; silencing AKT2 blocked these effects. Meanwhile, PKM2 overexpression was unable to increase AKT2 expression. The expressions of p-PI3K, p-AKT2, and PKM2 were increased when stimulated by epidermal growth factor (EGF); however, these expressions were blocked when inhibited the PI3K by LY294002. STAT3 expression was elevated and NF-κB p65 nuclear translocation was activated both in vitro and in vivo when either AKT2 or PKM2 was overexpressed; and these effects were inhibited when silencing AKT2 expression. Taken together, AKT2 increases the migration and invasion of ovarian cancer cells in vitro and promotes lung metastasis in nude mice in vivo through PKM2-mediated elevation of STAT3 expression and NF-κB activation. In conclusion, we highlight a novel mechanism of the AKT2-PKM2-STAT3/NF-κB axis in the regulation of ovarian cancer progression, and our work suggested that both AKT2 and PKM2 may be potential targets for the treatment of ovarian cancer.

Piperlongumine inhibits the proliferation, migration and invasion of fibroblast-like synoviocytes from patients with rheumatoid arthritis

OBJECTIVES

Recent studies have indicated that piperlongumine (PLM) may exert anti-inflammatory effects. In the present study, we determined the effect of PLM on the proliferation, apoptosis, migration and invasion of fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA) (referred to herein as RA FLS). We further explored the mechanisms by which the studied compound inhibits the functions of RA FLS.

METHODS

RA FLS viability and apoptosis were tested using MTT and Annexin V/PI assays, respectively. We performed an EDU assay to examine the proliferation of RA FLS. The migration and invasion of these cells were measured using a transwell chamber method and wound closure assay. The MMP-1, MMP-3, and MMP-13 levels in the culture supernatants of RA FLS were detected using a Luminex Assay kit. The intracellular ROS levels were detected using DCFH-DA. The expression levels of signal transduction proteins were measured using western blot.

RESULTS

We found that PLM induced apoptosis in RA FLS at concentrations of 15 and 20 μM. The proliferation of RA FLS was downregulated by PLM at concentrations of 1, 5 and 10 μM. Migration and invasion of RA FLS were reduced by PLM at concentrations of 1, 5 and 10 μM. PLM also inhibited cytoskeletal reorganization in migrating RA FLS and decreased TNF-α-induced intracellular ROS production. Moreover, we demonstrated the inhibitory effect of PLM on activation of the p38, JNK, NF-κB and STAT3 pathways.

CONCLUSIONS

Our findings suggest that PLM can inhibit proliferation, migration and invasion of RA FLS. Moreover, these data suggests that PLM might have therapeutic potential for the treatment of RA.

Paeoniflorin Inhibits Migration and Invasion of Human Glioblastoma Cells via Suppression Transforming Growth Factor β-Induced Epithelial-Mesenchymal Transition

Paeoniflorin (PF) is a polyphenolic compound derived from Radix Paeoniae Alba thathas anti-cancer activities in a variety of human malignancies including glioblastoma. However, the underlying mechanisms have not been fully elucidated. Epithelial to mesenchymal transition (EMT), characterized as losing cell polarity, plays an essential role in tumor invasion and metastasis. TGFβ, a key member of transforming growth factors, has been demonstrated to contribute to glioblastoma aggressiveness through inducing EMT. Therefore, the present studies aim to investigate whether PF suppresses the expression of TGFβ and inhibits EMT that plays an important role in anti-glioblastoma. We found that PF dose-dependently downregulates the expression of TGFβ, enhances apoptosis, reduces cell proliferation, migration and invasion in three human glioblastoma cell lines (U87, U251, T98G). These effects are enhanced in TGFβ siRNA treated cells and abolished in cells transfected with TGFβ lentiviruses. In addition, other EMT markers such as snail, vimentin and N-cadherin were suppressed by PF in these cell lines and in BALB/c nude mice injected with U87 cells. The expression of MMP2/9, EMT markers, are also dose-dependently reduced in PF treated cells and in U87 xenograft mouse model. Moreover, the tumor sizes are reduced by PF treatment while there is no change in body weight. These results indicate that PF is a potential novel drug target for the treatment of glioblastoma by suppression of TGFβ signaling pathway and inhibition of EMT.

FBW7 loss promotes epithelial-to-mesenchymal transition in non-small cell lung cancer through the stabilization of Snail protein

The E3 ubiquitin ligase F-box and WD repeat domain containing 7 (FBW7α) functions as a putative tumor suppressor in non-small cell lung cancer (NSCLC) due to its regulation of a set of oncogenic proteins associated with cell proliferation and mitosis. Increasing efforts have been focused on the understanding of FBW7 in determining cell cycle progression and apoptosis induction, however, the correlation between FBW7 and tumor metastasis is not fully understood. In this study, we reported a potential anti-metastatic effect of FBW7 in non-small cell lung cancer (NSCLC). In this model, FBW7 inhibited cancer cell metastasis primarily by inducing ubiquitination and proteolysis of the transcriptional factor Snail, which suppressed E-cadherin cell tight junction protein expression. Loss of FBW7 would stabilize the Snail protein, thus, inhibit E-cadherin expression and promote metastasis in vitro and in vivo. Moreover, Snail ubiquitination and degradation were also achieved by pharmacological approach, in which the FBW7 agonist oridonin treatment led to Snail proteolysis. Furthermore, FBW7 silencing stabilized Snail protein and induced epithelial-to mesenchymal transition (EMT), and acquisition of migration and invasion properties in NSCLC. Overall, our study provides new insights into the FBW7-Snail axis in regulating cell migration and invasion, and suggests that targeting FBW7 may be a potent approach to inhibit metastasis in NSCLC.

Caveolin-1 promotes pituitary adenoma cells migration and invasion by regulating the interaction between EGR1 and KLF5

Caveolin-1 (Cav-1) is a principal structural protein of caveolae. Cav-1 has been implicated in cancer progression, but its precise functional roles in pituitary adenoma cells remain largely unclear. In this study, we evidenced that the level of cav-1 was elevated in the invasive pituitary adenoma. Cav-1 knockdown restrained the migration and invasion of pituitary adenoma cells. In cav-1-depleting cells, the expression of miR-145, miR-124 and miR-183 were up-regulated. Further investigation showed that cav-1 knockdown inhibited the nuclear translocation of EGR1, reducing the interaction between EGR1 and KLF5. The resulting free KLF5 promoted the expression of miR-145, miR-124 and miR-183 by binding to their promoters, which was blocked by EGR1. Luciferase reporter assay indicated that miR-145 targeted FSCN1, miR-124 targeted PTTG1IP, and miR-183 targeted EZR in pituitary adenoma cells, respectively. Knockdown of FSCN1, PTTG1IP or EZR suppressed the migration and invasion of pituitary adenoma cells. In conclusion, our data suggested that the elevated cav-1 promoted pituitary adenoma cells migration and invasion by regulating the interaction between EGR1 and KLF5.

Keratin17 Promotes Tumor Growth and is Associated with Poor Prognosis in Gastric Cancer

Krt17 is a 48kDa protein member of keratin family. Previous literatures have demonstrated Krt17 may play a promotive role in the progression of various malignancies. However, the exact function of Krt17 in the carcinogenesis and the progression of gastric cancer (GC) remains unknown. In the present study, the expression of Krt17 in 20 fresh GC and matched normal tissues were detected and Krt17 was found to be significantly increased in GC tissues compared to normal tissues. And then the immunochemistry was performed to investigate the Krt17 expression in 569 GC tissue specimens, we found that the expression of Krt17 was remarkably positively correlated with the tumor size (P < 0.01), depth of invasion (T) (P < 0.001), lymph node metastasis (N) (P < 0.001), tumor node metastasis (TNM) stage (P < 0.001) and vascular invasion (P < 0.05). High expression of Krt17 predicted a poor prognosis of GC patients. In addition, we showed silencing of Krt17 inhibited GC cell proliferation, migration and invasion, and induced cell apoptosis by altering Bcl2 family protein expression and cleaved caspase3 upregulation. Moreover, silencing of Krt17 led to cell cycle arrest at G1/S stage by decreasing cyclin E1 and cyclin D expression. In conclusion, our findings revealed Krt17 can be used as a novel predictive biomarker, thus providing a novel therapeutic target for GC patients.

Sulfatase-1 knockdown promotes in vitro and in vivo aggressive behavior of murine hepatocarcinoma Hca-P cells through up-regulation of mesothelin

Our previous study (Oncotarget 2016; 7:46) demonstrated that the over-expression of sulfatase-1 in murine hepatocarcinoma Hca-F cell line (a murine HCC cell with lymph node metastatic [LNM] rate of >75%) downregulates mesothelin and leads to reduction in lymphatic metastasis, both in vitro and in vivo. In current work, we investigated the effects of Sulf-1 knockdown on mesothelin (Msln) and it's effects on the in vitro cell proliferation, migration, invasion, and in vivo tumor growth and LNM rate for Hca-P cells (a murine HCC cell with LNM rate of <25%). Western blotting and qRT-PCR assay indicated that both in vitro and in vivo Sulf-1 was down-regulated by 75% and 68% and led to up regulation of Msln by 55% in shRNA-transfected-Sulf-1-Hca-P cells compared with Hca-P and nonspecific sequence control plasmid transfected Hca-P cell (shRNA-Nc-Hca-P). The in vitro proliferation, migration and invasion potentials were significantly enhanced following Sulf-1 stable down-regulation. In addition, Sulf-1 knock-down significantly promoted tumor growth and increased LNM rates of shRNA-Sulf-1-Hca-P-transplanted mice by 78.6% (11 out of 14 lymph nodes were positive of cancer). Consistent with our previous work, we confirmed that Sulf-1 plays an important role in hepatocarcinoma cell proliferation, migration, invasion and metastasis. The interaction between Sulf-1 and Msln is a potential therapeutic target in the development of liver cancer therapy.

Down-regulation of IFITM1 and its growth inhibitory role in cervical squamous cell carcinoma

BACKGROUND

Cervical cancer is a major cause of death in women worldwide. Interferon-induced transmembrane protein 1 (IFITM1) is involved in antivirus defense, cell adhesion, and carcinogenesis in different tissues. However, the role of IFITM1 gene in cervical squamous cell cancer is unclear.

METHODS

To explore the role of IFITM1 in carcinogenesis of cervical cancer, we investigated the expression of IFITM1 gene in cervical squamous cell carcinoma. IFITM1 mRNA level was measured by real-time quantitative RT-PCR in cervical cancer tissues and their adjacent normal tissues. IFITM1 protein level was measured by immunohistochemistry. Methylation in the IFITM1 gene promoter was detected by methylation-specific PCR. We then transfected HeLa cells with IFITM1 expression vector or control vector. IFITM1 expression was examined; cell migration and invasion were analyzed by wound healing assay and matrigel-coated transwell migration assays, respectively. HeLa cell proliferation was measured by cell counting kit-8 assay and cell cycle analysis. Cell apoptosis was analyzed by Annexin V/propidium iodide double staining assay.

RESULTS

The difference in IFITM1 protein expression between samples from chronic cervicitis and cervical carcinoma was statistically significant (P < 0.01). Ki-67 and PCNA protein expression levels were significantly higher in cervical cancer tissues than in their corresponding cervicitis tissues (P < 0.05 and P < 0.001, respectively). IFITM1 mRNA level was significantly lower in cervical cancer tissues than in normal cervical tissues (P < 0.05). Methylation of the IFITM1 gene promoter was significantly higher in cervical cancer than in normal cervical tissues (P < 0.05). Transfection of the IFITM1 pcDNA3.1 construct decreased cell migration and invasion of HeLa cells, inhibited cell proliferation, and increased cell apoptosis.

CONCLUSION

IFITM1 gene expression may reduce the proliferation, migration, and invasion of cervical squamous cancer cells.

HOX transcript antisense intergenic RNA represses E-cadherin expression by binding to EZH2 in gastric cancer

AIM

To clarify the mechanisms of HOX transcript antisense intergenic RNA (HOTAIR) in gastric cancer (GC) migration and invasion.

METHODS

Quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression level of HOTAIR in GC tissues. The correlation of its expression with clinicopathological features was analyzed. Area under receiver operating characteristic curve (AUC_ROC) was constructed to evaluate the diagnostic value of HOTAIR. Wound-healing assay and Transwell assay were performed to detect the biological effects of HOTAIR in GC cells. qPCR, western blot and immunohistochemistry were used to evaluate the mRNA and protein expression of E-cadherin. RNA-binding protein immunoprecipitation was used for the analysis of EZH2 interactions with HOTAIR. Chromatin immunoprecipitation assay was performed to investigate direct interactions between EZH2 and E-cadherin.

RESULTS

The expression of HOTAIR was up-regulated in GC tumorous tissues compared with the para-tumorous tissues (P < 0.001). Its over-expression was correlated with tumor-node-metastasis (TNM) stage (P = 0.024), tumor invasion (P = 0.018), lymph node metastasis (P = 0.023), and poor prognosis (P < 0.001). Multivariate Cox regression analysis confirmed expression of HOTAIR as an independent predictor of overall survival (P = 0.033), together with TNM stage (P = 0.002) and lymph node metastasis (P = 0.002). The AUC_ROC was up to 0.709 (95%CI: 0.623-0.785, P < 0.001). Knockdown of HOTAIR by siRNA in GC cells suppressed the migration and invasion of GC cells. Significantly negative correlation between HOTAIR and E-cadherin was found in GC tissues and cell lines, and HOTAIR contributed to the regulation of E-cadherin through binding to EZH2 with the E-cadherin promoter.

CONCLUSION

HOTAIR may play a pivotal role in tumor cell migration and invasion. It can be used as a potential diagnostic and prognostic biomarker for GC.

Downregulation of miR-503 Promotes ESCC Cell Proliferation, Migration, and Invasion by Targeting Cyclin D1

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive cancers in China, but the underlying molecular mechanism of ESCC is still unclear. Involvement of microRNAs has been demonstrated in cancer initiation and progression. Despite the reported function of miR-503 in several human cancers, its detailed anti-oncogenic role and clinical significance in ESCC remain undefined. In this study, we examined miR-503 expression by qPCR and found the downregulation of miR-503 expression in ESCC tissue relative to adjacent normal tissues. Further investigation in the effect of miR-503 on ESCC cell proliferation, migration, and invasion showed that enhanced expression of miR-503 inhibited ESCC aggressive phenotype and overexpression of CCND1 reversed the effect of miR-503-mediated ESCC cell aggressive phenotype. Our study further identified CCND1 as the target gene of miR-503. Thus, miR-503 functions as a tumor suppressor and has an important role in ESCC by targeting CCND1.

CPEB4 promotes cell migration and invasion via upregulating Vimentin expression in breast cancer

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a member of CPEB family which is overexpressed in variety of cancers. However, the biological role and regulatory mechanism of CPEB4 in cancers remain unknown. Here, we first investigate the role of CPEB4 in breast cancer progression and metastasis. The expression of CPEB4 is elevated in breast cancer tissues compared with adjacent normal tissues. Furthermore, high expression levels of CPEB4 is associated with tumor metastasis in breast cancer patients. Ectopic expression of CPEB4 dramatically promotes EMT, migration and invasion of breast cancer cells, while silencing CPEB4 expression significantly reduces these events. Mechanically, overexpression of CPEB4 upregulates Vimentin expression and silencing Vimentin expression blocks CPEB4-induced migration and invasion of breast cancer cells. These results implicate the potential role of CPEB4 and Vimentin in breast cancer metastasis, which is further confirmed by the finding that there is a physical interaction between the two proteins. Altogether, our results provide a novel insight into CPEB4 in regulating breast cancer progression and metastasis.

CLDN-1 promoted the epithelial to migration and mesenchymal transition (EMT) in human bronchial epithelial cells via Notch pathway

Claudin-1 (CLDN-1) is one of main tight junction components that play an important role in epithelial-mesenchymal transition (EMT). However, the effects of CLDN-1 on the migration and EMT induced by TGF-β1 in primary normal human bronchial epithelial (NHBE) and BEAS-2B cells have not been clear. The expression of CLDN-1 was quantified by Western blotting in NHBE and BEAS-2B cells. Cell migration and invasion were detected using transwell assays. The expression level of E-cadherin, N-cadherin, α-SMA, and Vimentin was evaluated by quantitative real-time PCR and Western blotting. Here we showed that the protein expression of CLDN-1 was increased exposed to TGF-β1 in a dose- and time-dependent manner. Knockdown of CLDN-1 using small interfering CLDN-1 RNA (siCLDN-1) prevented the migration and invasion in NHBE and BEAS-2B cells. Moreover, depletion of CLDN-1 promoted the E-cadherin expression and decreased the mRNA and protein levels of N-cadherin, α-SMA, and Vimentin induced by TGF-β1. Furthermore, CLDN-1 silencing resulted in the reduction of the Notch intracellular domain (NICD) and hairy enhancer of split-1 (Hes-1) in mRNA and protein level. Jagged-1, an activator of Notch signaling pathway, abrogated the protective function of siCLDN-1 in migration and EMT. In conclusion, CLDN-1 promoted the migration and EMT through the Notch signaling pathway.

Depletion of p42.3 gene inhibits proliferation and invasion in melanoma cells

PURPOSE

The p42.3 gene is identified recently, and the upregulated expression has been characterized in a variety of human cancers and embryonic tissues but not yet in malignant melanoma. In this study, we explored the role of p42.3 gene in the development of melanoma.

METHODS

The expression of p42.3 was detected by immunohistochemistry staining of 261 cases of patient lesions, including nevi and melanoma, and its correlation with clinical pathological characteristics and prognosis was analyzed. Furthermore, a series of in vitro assays were used to investigate the biological function of p42.3 in melanoma cells.

RESULTS

Immunohistochemistry staining showed an elevated expression level of p42.3 in melanoma compared to nevi (P = 0.001). Statistical analysis indicated that this high level was well correlated with patients' clinical stage (P = 0.045), but not with gender, age, clinical type, mitotic rate, and overall survival (P > 0.05). Moreover, in vitro assays showed knockdown p42.3 gene expression could inhibit the biological profiling, including proliferation, migration, and invasion of melanoma cells, and also affect PI3K/Akt pathway, MAPK pathway, and β-catenin.

CONCLUSIONS

This study suggests that p42.3, acting like an oncogene, is involved in the malignant transformation process of melanoma and may serve as a biomarker for diagnostic and treatment purposes.

LncRNAs H19 and HULC, activated by oxidative stress, promote cell migration and invasion in cholangiocarcinoma through a ceRNA manner

Background

Long non-coding RNAs (lncRNAs) are known to play important roles in different cell contexts, including cancers. However, little is known about lncRNAs in cholangiocarcinoma (CCA), a cholangiocyte malignancy with poor prognosis, associated with chronic inflammation and damage to the biliary epithelium. The aim of the study is to identify if any lncRNA might associate with inflammation or oxidative stress in CCA and regulate the disease progression.

Methods

In this study, RNA-seqs datasets were used to identify aberrantly expressed lncRNAs. Small interfering RNA and overexpressed plasmids were used to modulate the expression of lncRNAs, and luciferase target assay RNA immunoprecipitation (RIP) was performed to explore the mechanism of miRNA-lncRNA sponging.

Results

We firstly analyzed five available RNA-seqs datasets to investigate aberrantly expressed lncRNAs which might associate with inflammation or oxidative stress. We identified that two lncRNAs, H19 and HULC, were differentially expressed among all the samples under the treatment of hypoxic or inflammatory factors, and they were shown to be stimulated by short-term oxidative stress responses to H₂O₂ and glucose oxidase in CCA cell lines. Further studies revealed that these two lncRNAs promoted cholangiocyte migration and invasion via the inflammation pathway. H19 and HULC functioned as competing endogenous RNAs (ceRNAs) by sponging let-7a/let-7b and miR-372/miR-373, respectively, which activate pivotal inflammation cytokine IL-6 and chemokine receptor CXCR4.

Conclusions

Our study revealed that H19 and HULC, up-regulated by oxidative stress, regulate CCA cell migration and invasion by targeting IL-6 and CXCR4 via ceRNA patterns of sponging let-7a/let-7b and miR-372/miR-373, respectively. The results suggest that these lncRNAs might be the chief culprits of CCA pathogenesis and progression. The study provides new insight into the mechanism linking lncRNA function with CCA and may serve as novel targets for the development of new countermeasures of CCA.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0348-0) contains supplementary material, which is available to authorized users.

Agkihpin, a novel SVAE may inhibit the migration and invasion of liver cancer cells associated with the inversion of EMT induced by Wnt/β-catenin signaling inhibition

In our previous work, agkihpin, a snake venom arginine esterase (SVAE), was isolated from the Gloydius halys Pallas, which could attenuate the migration of liver cancer cells. However, the mechanism of the effect of agkihpin on attenuating migration of liver cancer cell is unknown yet. Here, to learn more about agkihpin and explore the possibility of agkihpin as an anti-metastatic drug in the future, a series of experiments about the migration and invasion of liver cancer cells with agkihpin, HepG 2 and SMMC-7721, was conducted. Epithelial-mesenchymal transition (EMT) is an initial step and a major phenotype of cancer metastasis and invasion, while a number of EMT opposite phenomenons were observed, for example, epithelial marker E-cadherin was up-regulated, mesenchymal markers N-cadherin and Vimentin, and transcription regulators Snail and twist were down-regulated after treating with agkihpin in liver cancer cells; canonical Wnt/β-catenin pathway, one of the signals initiated EMT, was inhibited by decreased expressions of FZD7 and β-catenin, phosphorylation of GSK3β (Ser9), and nuclear β-catenin accumulation in agkihpin treated cancer cells. By using bioinformatics analysis and protease activity analysis in vitro we also found that agkihpin might bind and degrade FZD7. As a result, we hypothesized that agkihpin could inhibit the Wnt/β-catenin signaling pathway by cleaving FZD7, leading to the inactivation of the TCF/LEF transcription factor, which contributed to the inversion of EMT, and finally attenuated the migration and invasion of liver cancer cells. Therefore, our findings provided novel mechanistic insights into the role of SVAEs in liver cancer controlling, and raised the possibility that agkihpin may be used therapeutically in liver cancer.

Lobaplatin induces BGC-823 human gastric carcinoma cell apoptosis via ROS- mitochondrial apoptotic pathway and impairs cell migration and invasion

Human gastric cancer is the fifth common cancer with considerable metastasis potential, and its high incidence and mortality rate threaten public health. In this study, we examined the anticancer effects of lobaplatin on the human gastric carcinoma cell line BGC-823 in vitro, and explored its relative mechanisms. The results of MTT assay showed dose- and time-dependent cytotoxicity in BGC-823 cells with lobaplatin. Flow cytometry (FCM) assay indicated that lobaplatin affected BGC-823 cells' survival by inducing apoptosis. Western blot analysis also demonstrated that the occurrence of its apoptosis was associated with activation of Cleaved caspase-3 and Bax, downregulation of Bcl-2. Moreover, lobaplatin could also increase the reactive oxygen species (ROS) slightly and decrease the mitochondrial membrane potential (ΔYm) obviously, elucidating that lobaplatin may induce apoptosis via mitochondria-dependent apoptotic pathway. Furthermore, lobaplatin markedly blocked BGC-823 cells migration and invasion, and the reduction of matrix metalloproteinase (MMP) MMP-2 and MMP-9 expression were also observed in vitro. Our findings demonstrated the chemotherapeutic potential of lobaplatin for treatment of human gastric carcinoma cell line BGC-823 by inhibiting proliferation, inducing apoptosis and attenuating cell migration and invasion.

miRNA-135a promotes hepatocellular carcinoma cell migration and invasion by targeting forkhead box O1

AIMS

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. Many microRNAs (miRNAs), small non-coding RNAs, are involved in regulating cancer cell proliferation, metastasis, migration, invasion and apoptosis.

MAIN METHODS

We investigated the expression of miR-135a in HCC cell lines and clinical tissues. The effect of miR-135a on migration and invasion of HepG2 and MHCC-97L were examined using wound healing and Transwell assay. We determined the expression of miR-135a, forkhead box O1 (FOXO1), matrix metalloproteinase-2 (MMP-2) and Snail using real-time PCR and western blotting.

KEY FINDINGS

We found miR-135a was upregulated in HCC cell lines and tissues. miR-135a overexpression promoted HCC cells migration and invasion, whereas miR-135a inhibition suppressed HCC cells migration and invasion. miR-135a overexpression could upregulate the expression of MMP2, Snail and the phosphorylation of AKT, but decreased FOXO3a phosporylation. Tumor suppressor FOXO1 was the direct target for miR-135a.

SIGNIFICANCE

Our results suggested that miR-135a might play an important role in promoting migration and invasion in HCC and presents a novel mechanism of miRNA-mediated direct suppression of FOXO1 in HCC cells.

MicroRNA-655-3p functions as a tumor suppressor by regulating ADAM10 and β-catenin pathway in Hepatocellular Carcinoma

BACKGROUND

Increasing evidence suggests that microRNAs (miRNAs) play critical roles in malignant transformation, tumor progression and metastasis. Aberrant miR-655-3p expression has been associated with several cancers. However, the role and underlying mechanism of miR-655-3p in the development of hepatocellular carcinoma (HCC) remains unclear.

METHODS

MiR-655-3p expression was detected by quantitative RT-PCR (qRT-PCR) in human HCC tissues and cell lines. Cell proliferation was investigated using MTT and colony formation assays, and cell migration and invasion abilities were evaluated by transwell assay. ADAM10 protein expression was detected by immunohistochemical assay. The target gene and downstream of miR-655-3p were determined by qRT-PCR, western blot and dual-luciferase reporter assays.

RESULTS

miR-655-3p was significantly down-regulated in HCC tissues and HCC cell lines. Low miR-655-3p expression was negatively related to tumor size, portal vein tumor thrombosis (PVTT) status, TNM stage and metastasis status. In addition, miR-655-3p overexpression and depletion decreased and increased HCC cell proliferation, migration and invasion, respectively. Moreover, ADAM10 was identified as a direct target of miR-655-3p, and miR-655-3p down-regulated E-cadherin protein level and inhibits β-catenin pathway by mediating ADAM10.

CONCLUSIONS

MiR-655-3p might functions as a tumor suppressor by directly targeting ADAM10 and indirectly regulating β-catenin pathway in the development of progression of HCC. It may be a novel therapeutic candidate target to in HCC treatment.

Cryptotanshinone induces melanoma cancer cells apoptosis via ROS-mitochondrial apoptotic pathway and impairs cell migration and invasion

Melanoma is the most serious type of skin cancer because it is highly frequency of drug resistance and can spread earlier and more quickly than other skin cancers. The objective of this research was to investigate the anticancer effects of cryptotanshinone on human melanoma cells in vitro, and explored its mechanisms of action. Our results have shown that cryptotanshinone could inhibit cell proliferation in human melanoma cell lines A2058, A375, and A875 in a dose- and time-dependent manner. In addition, flow cytometry assay showed that cryptotanshinone inhibited the proliferation of human melanoma cell line A375 by blocking cell cycle progression in G2/M phase and inducing apoptosis in a concentration-dependent manner. Moreover, western blot analysis indicated that the occurrence of its apoptosis was associated with upregulation of cleaved caspases-3 and pro-apoptotic protein Bax while downregulation of anti-apoptotic protein Bcl-2. Meanwhile, cryptotanshinone could decrease the levels of reactive oxygen species (ROS). Furthermore, cryptotanshinone also blocked A375 cell migration and invasion in vitro which was associated with the downregulation with MMP-9. Taken together, these results suggested that cryptotanshinone might be a potential drug in human melanoma treatment by inhibiting proliferation, inducing apoptosis via ROS-mitochondrial apoptotic pathway and blocking cell migration and invasion.

PFDN1, an indicator for colorectal cancer prognosis, enhances tumor cell proliferation and motility through cytoskeletal reorganization

Prefoldin (PFDN) subunits have been reported upregulated in various tumor types, while the expression and functions of PFDN1 (PFDN subunit 1) in colorectal cancer (CRC) are not well elucidated. The aim of this study was to investigate the use of PFDN1 as a poor prognosis indicator for CRC and explore the functions of PFDN1 in CRC. The relationship between PFDN1 expression and CRC clinical-pathological statistics was detected on the tissue microarray containing 145 cases of CRC. ShRNA was used to silence PFDN1 expression in SW480 and RKO CRC cells, and these transfected cells were analyzed for changes in proliferation, colony formation, cell cycle, migration, and invasion. Immunofluorescence and immunoblot were used to determine the remodeling of the F-actin and α-tubulin. Finally, tumor growth on nude mice was observed and measured. In this study, we found PFDN1 was upregulated in CRC tissues compared with adjacent normal tissues. Also, PFDN1 expression positively correlated with tumor size and tumor invasion. Moreover, after silencing PFDN1 in SW480 and RKO cells, the proliferation and motility of CRC cells were significantly suppressed. The inhibitory effect of PFDN1 on tumor cell growth and motility was partially due to G2/M cell cycle blockage and cytoskeletal deficiency. Finally, in vivo assay showed that downregulation of PFDN1 inhibited tumor growth on nude mice and PFDN1 expression correlated with higher levels of Ki-67 staining. These findings indicate that PFDN1 was involved in the progression of CRC, and provide new insights into PFDN1 as a potential therapeutic target for CRC treatment.

Long noncoding RNA GAS5 suppresses the migration and invasion of hepatocellular carcinoma cells via miR-21

Long noncoding RNAs (lncRNAs) are aberrantly expressed in various cancers. Although lncRNA GAS5 (growth arrest-specific transcript 5) has been characterized as a tumor suppressor in some kinds of cancer, its role and function in hepatocellular carcinoma (HCC) remain unknown. The present report demonstrates that there are lower levels of GAS5, PDCD4, and PTEN and higher levels of microRNA-21 (miR-21) in HCC tissues than in adjacent normal tissues. Moreover, the levels of GAS5 and miR-21 were correlated with the clinicopathological characteristics of HCC. HCC patients with higher levels of GAS5 or with the lower levels of miR-21 have longer survival times. There are lower levels of GAS5 and higher levels of miR-21 in HCC cell lines (Be7402, SMMC-7721, and HCCLM3) than in normal liver L-02 cells, and the levels correlate with the aggression of the HCC cell lines. Knockdown of GAS5 upregulates miR-21 levels in Bel-7402 cells (weakly aggressive); in contrast, there are opposite changes in HCCLM3 cells (highly aggressive). Moreover, GAS5 that upregulated or downregulated the expression of PDCD4 and PTEN was reversed by inhibiting or overexpressing miR-21 level in Bel-7402 and HCCLM3 cells. Then, overexpression of GAS5 suppresses the migration and invasion of HCC cells and high expression of miR-21 largely eliminates GAS5-mediated suppression of HCC cell migration and invasion. Thus, GAS5 acts as a tumor suppressor in HCCs through negative regulation of miR-21 and its targets and proteins about migration and invasion in cancer cells, which may be a target for treating HCC.

Role of TGFβ signaling pathway in biological behavior of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignant tumor with a high fatality rate and strong invasion, and surgical resection is the most effective treatment for early HCC. However, most patients have lost the chance of operation at diagnosis. Additionally, chemotherapy has a poor effect and drug toxicity. In order to improve the prognosis and treatment of HCC, elucidating the cellular and molecular mechanism of HCC and finding new treatment targets are essential. The transforming growth factor β (TGFβ) pathway is involved in hepatocellular carcinogenesis and regulates tumor cell proliferation, apoptosis, migration, invasion and differentiation. TGFβ exerts a protective effect in early HCC. With the progression of HCC, TGFβ promotes the progress of HCC. Studies suggest that Axl/14-3-3zeta signaling is central for the transforming process. Taken into consideration the crucial role of the TGFβ pathway in the development and progression of HCC, it might become an important therapeutic target for HCC in the future.

Epigenetic downregulated ITGBL1 promotes non-small cell lung cancer cell invasion through Wnt/PCP signaling

Integrin, beta-like 1 (ITGBL1), is a β-integrin-related extracellular matrix protein which contains ten EGF-like repeats domain. Surprisingly, we screen Oncomine Database and found that ITGBL1 is more commonly downregulated in non-small cell lung cancer (NSCLC) tissues, and the result reminds us to explore its significance in NSCLC. Thus, we retrieved DRUGSURV Database and found that downregulated ITGBL1 predicts a poor prognosis of patients. These results provided us the clues that ITGBL1 might be a tumor suppressor in NSCLC. However, the biological functions of ITGBL1 have not been reported to date. In the current study, we surprisingly found that knockdown of ITGBL1 in NSCLC cell lines could promote cancer cell migration and invasion. Furthermore, recombinant ITGBL1 protein-treated cancer cell could inhibit cell migration and invasion. These results suggested that ITGBL1 plays a suppressive role in NSCLC progression. We further found that the downregulation of ITGBL1 might result from highly expressed miR-576-5p in NSCLC tissues, and the activity of Wnt/PCP signaling was enhanced when the level of ITGBL1 was inhibited. In conclusion, our results suggest that ITGBL1 is a novel tumor suppressor in NSCLC progression.

MMP2 and MMP9 participate in S1P-induced invasion of follicular ML-1 thyroid cancer cells

The bioactive lipid sphingosine-1-phosphate (S1P) has emerged as a potent inducer of cancer cell migration and invasion. Previously, we have shown that S1P induces invasion of ML-1 follicular thyroid cancer cells via S1P receptors 1 and 3 (S1P1,3). Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic enzymes used by cells for degradation of the extracellular matrix during invasion and migration. In the present study, we examined the role of MMP2 and MMP9 for S1P-induced invasion of ML-1 cells, and found that S1P regulates the secretion and activity of MMP2 and MMP9 via S1P1,3. Both pharmacological inhibitors and siRNA knockdown of MMP2 and MMP9 could attenuate S1P-induced invasion. Additionally, we show that calpains and Rac1 mediate S1P-induced secretion of MMP2 and MMP9. In conclusion, MMP2 and MMP9 participate in S1P-evoked follicular ML-1 thyroid cancer cell invasion.

Lobaplatin arrests cell cycle progression, induces apoptosis and impairs migration and invasion in B16-F10 melanoma cell line in vitro

Melanoma is highly resistant to most conventional treatment, and the incidence and mortality rates are increasing rapidly worldwide. The objective of this study was to determine the anticancer effects of lobaplatin on the melanoma carcinoma cell line B16-F10 in vitro, and explored its mechanisms of action. Our results have shown that lobaplatin inhibited cell proliferation in human melanoma A375 and CHL-1 cells and murine melanoma B16-F10 cells in a concentration- and time-dependent manner. Flow cytometry assay confirmed that lobaplatin affected B16-F10 cell survival by blocking cell cycle progression in G2/M phase and inducing apoptosis in a concentration-dependent manner. In addition, the apoptosis was associated with downregulation of anti-apoptotic protein Bcl-2 while upregulation of pro-apoptotic protein Bax. Lobaplatin could also decrease the mitochondrial membrane potential, indicating that lobaplatin may induce apoptosis via mitochondria-mediated apoptotic pathway. Furthermore, lobaplatin blocked B16-F10 cell migration and invasion in vitro. These results suggested that lobaplatin could be an effective chemotherapeutic agent in melanoma treatment by inhibiting proliferation, inducing apoptosis, cell cycle arrest and blocking cell migration and invasion.

MiR-132, miR-15a and miR-16 synergistically inhibit pituitary tumor cell proliferation, invasion and migration by targeting Sox5

MiR-132, miR-15a and miR-16 have been implicated in the pathogenesis of many types of cancer, including pituitary tumors. However, the molecular mechanism of these miRNAs in pituitary tumor growth and metastasis is still unclear. Here, we showed that miR-132 and miR-15a/16 were less expressed in pituitary tumor cell lines, as well as in invasive pituitary tumor tissues, compared to non-invasive tumor tissues. We described that overexpression of miR-132 and miR-15a/16 resulted in the suppression of pituitary tumor cell proliferation, migration and invasion, respectively, and also inhibits the expression of proteins involved in Epithelial to Mesenchymal Transition (EMT). Then, we show that these miRNAs synergistically target Sox5 in pituitary tumor. Moreover, we found that Sox5 overexpression partially rescued miR-132, miR-15a and miR-16-mediated inhibition of cell migration, invasion and cell growth. Finally, we confirmed that Sox5 was upregulated in invasive pituitary tumor tissues, compared to non-invasion tissues. In conclusion, our data indicate that miR-132 and miR-15a/16 act as tumor suppressor genes in pituitary tumor by directly targetting Sox5, and imply that these miRNAs have potential as therapeutic targets for invasive pituitary tumor.

Enhanced expression of long non-coding RNA ZXF1 promoted the invasion and metastasis in lung adenocarcinoma

The identification of cancer-associated long non-coding RNAs (LncRNA) and the investigation of their molecular and biological functions are important for understanding the molecular biology and progression of cancer. This study aims to find the key LncRNA associated with lung adenocarcinoma and to evaluate its biological role and clinical significance in tumor progression. Microarray analysis of 32,756 LncRNA was performed to screen the significantly different LncRNA between human lung adenocarcinoma tissues and adjacent non-cancerous lung tissues, which was named as LncRNA ZXF1. Expression of LncRNA ZXF1 was analyzed in 62 lung adenocarcinoma tissues and adjacent non-cancerous lung tissues by quantitative reverse-transcription PCR (qRT-PCR). Correlations between LncRNA ZXF1 expression and the clinicopathological features and prognosis of patients were also analyzed. The inhibition of LncRNA ZXF1 using siRNA treatment was performed in order to explore its role in tumor progression. The effect of LncRNA ZXF1 on proliferation was evaluated by CCK-8 assay using A549 cell lines, and cell migration and invasion were detected by transwell assays. Here we found that LncRNA ZXF1 levels were remarkably increased in lung adenocarcinoma tissues compared with adjacent non-cancerous lung tissues (P<0.05), and up-regulated LncRNA ZXF1 was correlated with lymph node metastasis (P<0.05), tumor pathological stage (P<0.05) and the extent of lymph node metastasis (correlation coefficient=0.366). The 3-year overall survival rate of patients with higher LncRNA ZXF1 levels was remarkably reduced compared with patients with lower LncRNA ZXF1 levels, implying that patients with high levels of LncRNA ZXF1expression had a relatively poor prognosis. Inhibition of LncRNA ZXF1 by siRNA decreased the migration and invasion of A549 cells in vitro, while there was no significant effect in cell proliferation.

MicroRNA let-7c inhibits migration and invasion of human non-small cell lung cancer by targeting ITGB3 and MAP4K3

MicroRNAs play an important regulatory role in carcinogenesis and cancer metastasis. Different members of let-7 family have been reported to be decreased in human lung tumors. However, the effect of specific let-7 member on metastasis of NSCLC remains undefined. Our current study detected the expression of let-7 members in 94 cases of NSCLC and a significant association was noticed between low levels of let-7c expression and metastasis, venous invasion, advanced TNM stages and poor survival of NSCLC patients. Consistently, ectopic expression of let-7c in relatively highly metastatic cells remarkably suppressed their migration and invasion. Inhibition of let-7c in cells with relatively low metastatic potential promoted their motility and invasion. We then analyzed the potential targets of let-7c and found that ITGB3 and MAP4K3 were directly repressed by let-7c. Upon restoring the expression of ITGB3 and MAP4K3, the effects of let-7c on tumor metastasis were partially reversed, and more importantly, the expression levels of ITGB3 and MAP4K3 were inversely correlated with let-7c in 64 NSCLC tissues. Collectively, our results suggest that let-7c, by degrading ITGB3 and MAP4K3, prevents NSCLC metastasis.