Astrocyte elevated gene-1 activates MMP9 to increase invasiveness of colorectal cancer

TRIM66 hastens the malignant progression of non-small cell lung cancer via modulating MMP9-mediated TGF-β/SMAD pathway

OBJECTIVE

To investigate regulatory function and underlying mechanism of TRIM66 in non-small cell lung cancer (NSCLC).

METHODS

TRIM66 and MMP9 expression in NSCLC cells and tissues was assayed via qRT-PCR and western blot. CCK-8, colony formation, Transwell and flow cytometry assays were conducted to measure cell functional alternations in NSCLC. Western blot was employed to measure expression as well as phosphorylation levels of epithelial-mesenchymal transition-(EMT) and TGF-β/SMAD pathways-related proteins. Co-immunoprecipitation (Co-IP) assay was done to probe interaction between TRIM66 and MMP9. Xenograft in vivo experiment and tumor metastasis model in nude mice were utilized to investigate effects of TRIM66 on tumor growth of NSCLC.

RESULTS

TRIM66 and MMP9 were conspicuously highly expressed in NSCLC cells and tissues. High TRIM66 level was markedly correlated with metastasis. Silencing TRIM66 prominently repressed the proliferation, migration and invasion of transfected cells, while inducing cell apoptosis. Whereas forced expression of TRIM66 exerted the opposite effect. The aberrant expression of TRIM66 modulated EMT pathway. TRIM66 also regulated MMP9 expression, and the interaction between them was validated by Co-IP assay. Overexpression of MMP9 could activate TGF-β/SMAD pathway. Rescue experiments manifested that si-MMP9 or SB431542 could partially reverse phenotypes induced by TRIM66. In vivo experiments revealed that silencing TRIM66 could hamper NSCLC tumor growth and metastasis.

CONCLUSION

TRIM66 and MMP9 were up-regulated in NSCLC. TRIM66 facilitated the malignant progression of NSCLC through modulating MMP9-mediated TGF-β/SMAD pathway.

Metadherin-mediated mechanisms in human malignancies

Metadherin (MTDH) has been recognized as a novel protein that is critical for the progression of multiple types of human malignancies. Studies have reported that MTDH enhances the metastatic potential of cancer cells by regulating multiple signaling pathways. miRNAs and various tumor-related proteins have been shown to interact with MTDH, making it a potential therapeutic target as well as a biomarker in human malignancies. MTDH plays a critical role in inflammation, angiogenesis, hypoxia, epithelial-mesenchymal transition and autophagy. In this review, we present the function and mechanisms of MTDH for cancer initiation and progression.

Expression of astrocyte-elevated gene-1 indicates prognostic value of fluoropyrimidine-based adjuvant chemotherapy in resectable stage III colorectal cancer

It is unclear which prognostic factor such as pathological features and gene mutation are majorly relevant for stage III disease and whether they aid in determining patients who will be benefit from postoperative adjuvant chemotherapy. The expression of astrocyte-elevated gene-1 (AEG-1), thymidylate synthase (TS), excision repair cross-complementation group 1 (ERCC1), epidermal growth factor receptor (EGFR), and vascular endothelial growth factor (VEGF) was examined to investigate their role in adjuvant chemotherapy for patients with resectable stage III colorectal cancer (CRC). A significant positive correlation was observed between AEG-1, TS, ERCC1, EGFR, and VEGF gene expression levels in CRC cell lines, and low AEG-1 and TS expression were highly sensitive to 5-fluorouracil treatment. Our results showed that AEG-1 expression was high in T4 and caused CRC recurrence or metastasis. Patients with T4, high AEG-1, TS and VEGF expression had a significantly short disease-free survival and overall survival. In multivariate Cox regression analysis, high AEG-1 expression could be an independent prognostic factor indicating poor survival in patients with resectable stage III CRC treated with adjuvant chemotherapy. In conclusion, AEG-1 expression and tumor grade are potential prognostic factors for recurrence and survival in patients with stage III CRC receiving adjuvant fluoropyrimidine-based chemotherapy.

Serious neonatal morbidities are associated with differences in DNA methylation among very preterm infants

Background

Infants born very preterm are more likely to experience neonatal morbidities compared to their term peers. Variations in DNA methylation (DNAm) associated with these morbidities may yield novel information about the processes impacted by these morbidities.

Methods

This study included 532 infants born < 30 weeks gestation, participating in the Neonatal Neurobehavior and Outcomes in Very Preterm Infants study. We used a neonatal morbidity risk score, which was an additive index of the number of morbidities experienced during the NICU stay, including bronchopulmonary dysplasia (BPD), severe brain injury, serious neonatal infections, and severe retinopathy of prematurity. DNA was collected from buccal cells at discharge from the NICU, and DNAm was measured using the Illumina MethylationEPIC. We tested for differential methylation in association with the neonatal morbidity risk score then tested for differentially methylated regions (DMRs) and overrepresentation of biological pathways.

Results

We identified ten differentially methylated CpGs (α Bonferroni-adjusted for 706,278 tests) that were associated with increasing neonatal morbidity risk scores at three intergenic regions and at HPS4, SRRD, FGFR1OP, TNS3, TMEM266, LRRC3B, ZNF780A, and TENM2. These mostly followed dose–response patterns, for 8 CpGs increasing DNAm associated with increased numbers of morbidities, while for 2 CpGs the risk score was associated with decreasing DNAm. BPD was the most substantial contributor to differential methylation. We also identified seven potential DMRs and over-representation of genes involved in Wnt signaling; however, these results were not significant after Bonferroni adjustment for multiple testing.

Conclusions

Neonatal DNAm, within genes involved in fibroblast growth factor activities, cellular invasion and migration, and neuronal signaling and development, are sensitive to the neonatal health complications of prematurity. We hypothesize that these epigenetic features may be representative of an integrated marker of neonatal health and development and are promising candidates to integrate with clinical information for studying developmental impairments in childhood.

The long non-coding RNA HCG18 promotes the growth and invasion of colorectal cancer cells through sponging miR-1271 and upregulating MTDH/Wnt/β-catenin

Long non-coding RNAs (lncRNAs) have recently emerged as key regulators of the occurrence and progression of various human cancers, including colorectal cancer. However, the regulatory mechanism of lncRNAs in the tumorigenesis of colorectal cancer remains poorly understood. In this study, we aimed to elucidate the potential role of lncRNA HCG18 in colorectal cancer. Herein, we found that HCG18 expression was significantly upregulated in colorectal cancer tissues and cell lines. Knockdown of HCG18 significantly inhibited the growth and invasion of colorectal cancer cells, while its overexpression had the opposite effect. Moreover, HCG18 was identified as a sponge of miR-1271. Our results showed that knockdown of HCG18 markedly upregulated miR-1271 expression in colorectal cancer cells. Notably, HCG18 expression was inversely correlated with miR-1271 expression in colorectal cancer specimens. Further investigation revealed that HCG18 contributed to the enhancement of MTDH/Wnt/β-catenin signalling in colorectal cancer cells. The antitumour effect of HCG18 inhibition was significantly reversed by miR-1271 inhibition or MTDH overexpression. Overall, the results of our study demonstrate that HCG18 exerts a potential oncogenic function in colorectal cancer by enhancing MTDH/Wnt/β-catenin signalling via sponging of miR-1271, highlighting the importance of HCG18/miR-1271/ MTDH/Wnt/β-catenin signalling in the progression of colorectal cancer.

Metadherin: A Therapeutic Target in Multiple Cancers

Altered expression of many genes and proteins is essential for cancer development and progression. Recently, the affected expression of metadherin (MTDH), also known as AEG-1 (Astrocyte Elevated Gene 1) and Lyric, has been implicated in various aspects of cancer progression and metastasis. Elevated expression of MTDH/AEG-1 has been reported in many cancers including breast, prostate, liver, and esophageal cancers, whereas its expression is low or absent in non-malignant tissues. These expression studies suggest that MTDH may represent a potential tumor associated antigen. MTDH also regulates multiple signaling pathways including PI3K/Akt, NF-κB, Wnt/β-catenin, and MAPK which cooperate to promote the tumorigenic and metastatic potential of transformed cells. Several microRNA have also been found to be associated with the increased MTDH expression in different cancers. Increased MTDH levels were linked to the tumor chemoresistance making it an attractive novel therapeutic target. In this review, we summarize data on MTDH function in various cancers.

MicroRNA-30a Mediates Cell Migration and Invasion by Targeting Metadherin in Colorectal Cancer

MicroRNAs play critical roles in the occurrence and progression in various cancers including colorectal cancer. Here, we found that microRNA-30a expression was significantly downregulated in colorectal cancer tissues compared to adjacent noncancerous tissues, and the suppression levels of microRNA-30a were significantly associated with tumor differentiation and lymph node metastasis. We also discovered that the expression level of microRNA-30a was inversely proportional to the invasive potential of several colorectal cancer cell lines. Moreover, overexpression of microRNA-30a in colorectal cancer cells inhibited activity of cell migration and invasion. Luciferase reporter assay confirmed metadherin could be a direct target of microRNA-30a, as the overexpression of microRNA-30a decreased metadherin expression at both the protein and messenger RNA levels. Furthermore, the knockdown of metadherin expression in SW620 significantly decreased cell metastasis and invasion. The upregulation of metadherin at the protein level negatively correlated with the expression of microRNA-30a in colorectal cancer tissues, and this upregulation could partially attenuate the effect induced by microRNA-30a. These findings indicate that microRNA-30a may act as a tumor suppressor in colorectal cancer and that microRNA-30a represses cell migration and invasion by decreasing metadherin, highlighting the therapeutic potential of microRNA-30a and metadherin in colorectal cancer treatment.

MicroRNAs, long noncoding RNAs, and circular RNAs: potential tumor biomarkers and targets for colorectal cancer

Noncoding RNAs (ncRNAs) can be divided into microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), pRNAs, and tRNAs. Traditionally, miRNAs exert their biological function mainly through the inhibition of translation via the induction of target RNA transcript degradation. lncRNAs and circRNAs were once considered to have no potential to code proteins. Here, we will review the current knowledge on ncRNAs in relation to their origins, characteristics, and functions. We will also review how ncRNAs work as competitive endogenous RNA, gene transcription and expression regulators, and RNA-binding protein sponges in colorectal cancer (CRC). Notably, except for the abovementioned mechanisms, recent advances revealed that lncRNAs can also act as the precursor of miRNAs, and a small portion of lncRNAs and circRNAs was verified to have the potential to code proteins, providing new evidence for the significance of ncRNAs in CRC tumorigenesis and development.

AEG-1 knockdown in colon cancer cell lines inhibits radiation-enhanced migration and invasion in vitro and in a novel in vivo zebrafish model

Background

Radiotherapy is a well-established anti-cancer treatment. Although radiotherapy has been shown to significantly decrease the local relapse in rectal cancer patients, the rate of distant metastasis is still very high. The aim of this study was to evaluate whether AEG-1 is involved in radiation-enhanced migration and invasion in vitro and in a novel in vivo zebrafish model.

Results

Migration and invasion were decreased in all the AEG-1 knockdown cell lines. Furthermore, we observed that radiation enhanced migration and invasion, while AEG-1 knockdown abolished this effect. The results from the zebrafish embryo model confirmed the results obtained in vitro. MMP-9 secretion and expression were decreased in AEG-1 knockdown cells.

Materials and Methods

We evaluated the involvement of AEG-1 in migration and invasion and, radiation-enhanced migration and invasion by Boyden chamber assay in three colon cancer cell lines and respective stable AEG-1 knockdown cell lines. Furthermore, we injected those cells into zebrafish embryos and evaluated the amount of disseminated cells into the tail.

Conclusion

AEG-1 knockdown inhibits migration and invasion, as well as radiation-enhanced invasion both in vitro and in vivo. We speculate that this is done via the downregulation of the intrinsic or radiation-enhanced MMP-9 expression by AEG-1 in the cancer cells. This study also shows, for the first time, that the zebrafish is a great model to study the early events in radiation-enhanced invasion.

Downregulation of miR-199b is associated with distant metastasis in colorectal cancer via activation of SIRT1 and inhibition of CREB/KISS1 signaling

The progression of distant metastasis cascade is a multistep and complicated process, frequently leading to a poor prognosis in cancer patients. Recently, growing evidence has indicated that deregulation of microRNAs (miRNAs) contributes to tumorigenesis and tumor progression in colorectal cancer (CRC). In the present study, by comparing the miRNA expression profiles of CRC tissues and corresponding hepatic metastasis tissues, we established the downregulation of miR-199b in CRC metastasis tissues. The decrease in miR-199b expression was significantly correlated to late TNM stage and distant metastasis. Moreover, Kaplan–Meier curves showed that CRC patients with high expression level of miR-199b had a longer median survival. Functional assays results indicated that the restoration of miR-199b considerably reduced cell invasion and migration in vitro and in vivo, and increased the sensitivity to 5-FU and oxaliplatin. Further dual-luciferase reporter gene assays revealed that SIRT1 was the direct target of miR-199b in CRC. The expression of miR-199b was inversely correlated with SIRT1 in CRC specimens. SIRT1 knockdown produced effects on biological behavior that were similar to those of miR-199b overexpression. Furthermore, through Human Tumor Metastasis PCR Array we discovered KISS1 was one of the downstream targets of SIRT1. Silencing of SIRT1 upregulated KISS1 expression by enhancing the acetylation of the transcription factor CREB. The latter was further activated via binding to the promoter of KISS1 to induce transcription. Thus, we concluded that miR-199b regulates SIRT1/CREB/KISS1 signaling pathway and might serve as a prognosis marker or a novel therapeutic target for patients with CRC.

Downregulation of miR-199b is associated with distant metastasis in colorectal cancer via activation of SIRT1 and inhibition of CREB/KISS1 signaling

Surface CD24 has previously been described, together with CD44 and ESA, for the characterization of putative cancer stem cells in pancreatic ductal adenocarcinoma (PDAC), the most fatal of all solid tumors. CD24 has a variety of biological functions including the regulation of invasiveness and cell proliferation, depending on the tumor entity and subcellular localization. Genetically engineered mouse models (GEMM) expressing oncogenic Kras^G12D recapitulate the human disease and develop PDAC. In this study we investigate the function of CD24 using GEMM of endogenous PDAC and a model of cerulein-induced acute pancreatitis. We found that (i) CD24 expression was upregulated in murine and human PDAC and during acute pancreatitis (ii) CD24 was expressed exclusively in differentiated PDAC, whereas CD24 absence was associated with undifferentiated tumors and (iii) membranous CD24 expression determines tumor subpopulations with an epithelial phenotype in grafted models. In addition, we show that CD24 protein is stabilized in response to WNT activation and that overexpression of CD24 in pancreatic cancer cells upregulated β-catenin expression augmenting an epithelial, non-metastatic signature. Our results support a positive feedback model according to which (i) WNT activation and subsequent β-catenin dephosphorylation stabilize CD24 protein expression, and (ii) sustained CD24 expression upregulates β-catenin expression. Eventually, membranous CD24 augments the epithelial phenotype of pancreatic tumors. Thus we link the WNT/β-catenin pathway with the regulation of CD24 in the context of PDAC differentiation.

HCRP1 is downregulated in non-small cell lung cancer and regulates proliferation, invasion, and drug resistance

HCRP1 has been reported to have tumor suppressive function. However, its expression pattern and function in human non-small cell lung cancer (NSCLC) remain obscure. This study aims to explore clinical significance of HCRP1 in NSCLC. Immunohistochemical results showed high HCRP1 protein in normal bronchial epithelial tissue and downregulated HCRP1 expression in 47/98 lung cancer specimens. HCRP1 downregulation correlated with clinical stage (p = 0.0203), nodal status (p = 0.0168), and poor patient prognosis (log-rank, p = 0.0076). Univariate analysis showed that TNM stage (p < 0.0001) and HCRP1 (p = 0.0098) were significant prognostic factors; Cox regression model showed that TNM stage serves as an independent prognostic factor (p = 0.0011). We also found that HCRP1 was downregulated in lung cancer cells compared with normal HBE cells. HCRP1 plasmid transfection in H1299 cells inhibited proliferation, cell cycle progression, and invasion. HCRP1 depletion in A549 cells showed the opposite biological effects. In addition, we found that HCRP1 could inhibit MAPK and AKT signaling with downregulation of ERK and AKT phosphorylation, cyclin proteins, Bcl2 and MMP9, while HCRP1 depletion activated ERK and AKT signaling. The level of EGFR phosphorylation was also inhibited by HCRP1. In addition, we found that HCRP1 depletion confers multidrug resistance in H1299 cells. We employed paclitaxel and cisplatin in A549 cells with HCRP1 depletion. HCRP1 depletion decreased the effect of paclitaxel and cisplatin in A549 cells. Treatment with EGFR inhibitor AG1478 and AKT inhibitor LY249004 abolished the effect of HCRP1 depletion on drug resistance. In conclusion, the present study demonstrate that HCRP1 is downregulated in NSCLC and regulates proliferation, invasion, and drug resistance through modulation of EGFR signaling.

[LRRC3B is Downregulated in Non-small Cell Lung Cancer and Connected with Cell Proliferation and Invasion]

背景与目的

已有的研究表明：在许多恶性肿瘤细胞中，LRRC3B表达显著下调，被视为肿瘤抑制蛋白。然而，在非小细胞肺癌中它的表达模式和生物学作用缺乏研究。人类癌症微阵列的研究显示LRRC3B在乳腺癌和结肠直肠癌表达下调，提示LRRC3B参与致癌作用。本研究的目的是研究LRRC3B在非小细胞肺癌中的必到状态及其与肺癌增殖、侵袭和细胞周期间的相关性，探讨LRRC3B在调控肺癌细胞增殖、侵袭及细胞周期中的作用。

方法

应用Western blot和Realtime RT-PCR检测LRRC3B在几株肺癌细胞系中的mRNA和蛋白表达水平。应用MTT法检测对转染LRRC3B的A549和H460细胞系细胞增殖能力变化，应用集落形成实验以及细胞侵袭实验研究LRRC3B对细胞增殖和侵袭以及细胞周期进程的作用。肺癌细胞系H3255中转染LRRC3B siRAN验证LRRC3B对细胞的增殖以及侵袭能力和对细胞周期进程的影响。

结果

与正常NHBE细胞系相比，NSCLC细胞系中LRRC3B蛋白表达量显著下调，特别是H460、H358、HCC827以及A549。A549和H460细胞系转染LRRC3B后，细胞增殖和侵袭能力受到抑制。LRRC3B抑制细胞周期进程，并下调cyclin D1和MMP9的表达。H3255细胞中敲除LRRC3B，细胞增殖和侵袭能力显著增强，同时与细胞周期及侵袭能力相关的蛋白cyclin D1和MMP9表达略微上调。

结论

LRRC3B在肺癌细胞系中表达下调，而上调LRRC3B则能够抑制肺癌细胞增殖和侵袭能力，并抑制细胞周期进程，可能是未来肺癌治疗的一个新靶点。

Tumor evolution and intratumor heterogeneity in colorectal carcinoma: insights from comparative genomic profiling of primary tumors and matched metastases

Metastatic colorectal cancer (CRC) is one of the leading causes of cancer-related mortality among men and women worldwide. Over the past few decades, advances in our understanding of the genetic and epigenetic underpinnings of CRC have led to important insights into the pathogenesis of invasive tumors and have identified different molecular subgroups. Nonetheless, the events that might facilitate dissemination of tumor cells to distant sites giving rise to metastatic disease are not well characterized. Furthermore, in contrast to intertumor heterogeneity the extent of intratumor heterogeneity in different types of CRC has not been fully defined. In this paper, we review studies that have compared the genetic profile of primary invasive carcinomas to that of matched metastases and discuss the implications of their findings for our understanding of tumor evolution and for the clinical management of patients with advanced CRC.

RASSF4 is downregulated in nonsmall cell lung cancer and inhibits cancer cell proliferation and invasion

RASSF4 has been implicated as a tumor suppressor in several human cancers. Its clinical significance and biological characteristics in human nonsmall cell lung cancer (NSCLC) have not been explored yet. In this study, we explored expression pattern of RASSF4 in 89 NSCLC specimens. The results showed that RASSF4 was downregulated in 36/89 NSCLC tissues compared with normal tissue. RASSF4 downregulation significantly associated with advanced TNM stage, positive nodal status, and poor prognosis. We examined RASSF4 protein expression in normal lung epithelial cell line and lung cancer lines. We found that RASSF4 expression was downregulated in four of seven lung cancer cell lines compared with normal bronchial epithelial cells. RASSF4 plasmid transfection was performed in H460 and A549 cell lines. RASSF4 overexpression inhibited proliferation, colony formation, and invading ability. In addition, we identified that RASSF4 could inhibit cell cycle progression with downregulation of cyclin D1. Expression of invasion-related protein MMP2, MMP9 was also decreased. In conclusion, the present study suggested that RASSF4 serves as an important tumor suppressor in NSCLC.

LRRC3B is downregulated in non-small-cell lung cancer and inhibits cancer cell proliferation and invasion

LRRC3B has emerged as a tumor suppressor in several human cancers. However, its expression pattern and biological roles in human non-small-cell lung cancer (NSCLC) have not been explored. In the present study, we investigated clinical significance of LRRC3B in 101 NSCLC specimens. We found that LRRC3B expression was downregulated in NSCLC tissues compared with normal bronchial epithelium and that its downregulation significantly correlated with tumor-node-metastasis (TNM) stage (p < 0.0001), nodal metastasis (p < 0.0001), and poor patient prognosis (p = 0.0016, log-rank test). We also checked LRRC3B levels in several lung cancer cell lines and found that its expression was downregulated in four of nine lung cancer cell lines compared with normal human bronchial epithelial (NHBE) cell line. We further explored the biological role of LRRC3B. LRRC3B plasmid transfection in H460 and A549 cell lines inhibited proliferation, colony formation ability, and invading ability. Furthermore, we identified that LRRC3B could inhibit cell cycle progression with downregulation of cyclin D1 and decreased MMP9 expression. In addition, LRRC3B depletion in HBE cells promoted proliferation and invasion. In conclusion, our data suggested that LRRC3B may serve as an important tumor suppressor in NSCLC.

A role of MMP-14 in the regulation of invasiveness of nasopharyngeal carcinoma

Although matrix metalloproteinase 14 (MMP-14) has been shown to play a substantial role in the carcinogenesis of some types of cancer, its involvement in the pathogenesis of nasopharyngeal carcinoma (NPC) has not been reported. Here, we analyzed MMP-14 levels in the NPC specimens from patients and compared with the paired normal nasopharynx (NNP) tissues. We found that NPC had significantly higher messenger RNA (mRNA) and protein levels of MMP-14. Moreover, higher levels of MMP-14 correlated with more advanced status of clinical stage and lymphatic metastasis. In vitro, MMP-14 levels determined the potential of invasiveness of NPC cells, possibly through induction of EMT-associated genes. Our data thus highlight MMP-14 as a novel therapeutic target for NPC.

Thyroid carcinoma cells produce PLGF to enhance metastasis

Cancer neovascularization is essential for metastasis of thyroid carcinoma. However, the underlying molecular mechanisms are ill-defined. Recently, placental growth factor (PLGF) has been shown to play critical roles in the pathological angiogenesis through regulating matrix metalloproteinases (MMPs); here, we were prompted to examine the role of PLGF in the metastasis of thyroid carcinoma. We found that the PLGF and MMP9 levels strongly correlated in the thyroid carcinoma specimen. Higher PLGF and MMP9 levels were detected in the thyroid carcinoma with metastasis. Using a human thyroid carcinoma cell line, TT, we found that overexpression of PLGF in TT cells increased expression of MMP9, while inhibition of PLGF in TT cells decreased expression of MMP9. However, modification of MMP9 levels in TT cells did not affect PLGF levels, suggesting that PLGF may regulate MMP9 in thyroid carcinoma cells. Moreover, application of a specific MAPK p42/p44 inhibitor, but not the application of a specific MAPK p38 inhibitor or specific Akt or JNK inhibitors, substantially abolished the effect of PLGF on MMP9 activation, suggesting that PLGF may increase expression of MMP9 via p42/p44 signaling pathway. Together, these data suggest that antagonizing PLGF in thyroid carcinoma cells may be a promising therapy to suppress cancer metastasis.

MicroRNA-217 functions as a prognosis predictor and inhibits colorectal cancer cell proliferation and invasion via an AEG-1 dependent mechanism

Background

Recent studies have indicated the possible function of miR-217 in tumorigenesis. However, the roles of miR-217 in colorectal cancer (CRC) are still largely unknown.

Methods

We examined the expression of miR-217 and AEG-1 in 50 CRC tissues and the corresponding noncancerous tissues by qRT-PCR. The clinical significance of miR-217 was analyzed. CRC cell lines with miR-217 upregulation and AEG-1 silencing were established and the effects on tumor growth in vitro and in vivo were assessed. Dual-luciferase reporter gene assays were also performed to investigate the interaction between miR-217 and AEG-1.

Results

Our data demonstrated that miR-217 was significantly downregulated in 50 pairs of colorectal cancer tissues. MiR-217 expression levels were closely correlated with tumor differentiation. Moreover, decreased miR-217 expression was also associated with shorter overall survival of CRC patients. MiR-217 overexpression significantly inhibited proliferation, colony formation and invasiveness of CRC cells by promoting apoptosis and G0/G1 phase arrest. Interestingly, ectopic miR-217 expression decreased AEG-1 expression and repressed luciferase reporter activity associated with the AEG-1 3′-untranslated region (UTR). AEG-1 silencing resulted in similar biological behavior changes to those associated with miR-217 overexpression. Finally, in a nude mouse xenografted tumor model, miR-217 overexpression significantly suppressed CRC cell growth.

Conclusions

Our findings suggest that miR-217 has considerable value as a prognostic marker and potential therapeutic target in CRC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1438-z) contains supplementary material, which is available to authorized users.

Larynx carcinoma regulates tumor-associated macrophages through PLGF signaling

Cancer neovascularization plays an essential role in the metastasis of larynx carcinoma (LC). However, the underlying molecular mechanisms are not completely understood. Recently, we reported that placental growth factor (PLGF) regulates expression of matrix metalloproteinase 3 (MMP3) through ERK/MAPK signaling pathway in LC. Here, we show that MMP9 upregulated in LC, and appeared to be mainly produced by M2 macrophages (tumor-associated macrophages (TAM)). In a transwell co-culture system, PLGF secreted by LC cells triggered macrophage polarization to a TAM subtype that releases MMP9. Moreover, MMP9 was found to be activated in the PLGF-polarized TAM via transforming growth factor β (TGFβ) receptor signaling activation. Furthermore, PLGF in LC cells induced macrophage polarization in vivo, and significantly promoted the growth of LC. Thus, together with our previous work, our study highlights a pivotal role of cross-talk between TAM and LC in regulating the metastasis of LC.

Vascular endothelial growth factor B coordinates metastasis of non-small cell lung cancer

Neovascularization is critical for the invasion and metastasis of non-small cell lung cancer (NSCLC). However, the molecular mechanism underlying the control of neovascularization of NSCLC is not completely understood. Both vascular endothelial growth factor B (VEGF-B) and matrix metalloproteinases 9 (MMP9) play essential roles in neovascularization of NSCLC. Here, we examined whether VEGF-B and MMP9 may affect each other to coordinate the neovascularization process in NSCLC. We found strong positive correlation of VEGF-B and MMP9 levels in the NSCLC from the patients. Moreover, patients that had NSCLC with metastasis had significantly higher levels of VEGF-B and MMP9 in the primary cancer. Using a human NSCLC line A549, we found that overexpression of VEGF-B increased expression of MMP9, while inhibition of VEGF-B decreased expression of MMP9. On the other hand, overexpression of MMP9 increased expression of VEGF-B, while inhibition of MMP9 decreased expression of VEGF-B. These data suggest that expression of VEGF-B and MMP9 may activate each other to enhance neovascularization. We then analyzed the underlying mechanism. Application of a specific ERK/MAPK inhibitor but not a PI3K/Akt inhibitor to VEGF-B-overexpressing A549 cells substantially abolished the effect of VEGF-B on MMP9 activation, while application of a specific PI3K/Akt inhibitor but not an ERK/MAPK inhibitor to MMP9-overexpressing A549 cells substantially abolished the effect of MMP9 on VEGF-B activation, suggesting that VEGF-B may activate MMP9 via ERK/MAPK signaling pathway, while MMP9 may activate VEGF-B via PI3K/Akt signaling pathway. Thus, our data highlight a coordinating relationship between VEGF-B and MMP9 in the regulation of neovascularization in NSCLC.

Nrdp1 inhibits metastasis of colorectal cancer cells by EGFR signaling-dependent MMP7 modulation

The molecular mechanism underlying cancer invasiveness and metastasis of colorectal cancer (CRC) remains elusive. Here we reported a strong correlation of the levels of neuregulin receptor degradation protein-1 (Nrdp1) and matrix metalloproteinase-7 (MMP7) in CRC from the patients. We then used a human CRC line, Caco-2, to study the underlying molecular basis. We found that Nrdp1 inhibited the phosphorylation of ErB3, a key player in epidermal growth factor receptor (EGFR) signaling in Caco-2 cells, which is required for activation of MMP7 to promote cell invasion. Our findings thus reveal Nrdp1, EGFR signaling, and MMP7 as promising therapeutic targets for preventing the metastasis of CRC.

SEMA4b inhibits MMP9 to prevent metastasis of non-small cell lung cancer

Semaphorin 4B (SEMA4b) has been shown to play a substantial role in the invasion of non-small cell lung cancer (NSCLC). However, the regulation mechanism of SEMA4b is largely elusive. Here, we reported significant decrease in SEMA4b level and significant increase in MMP9 level in NSCLC compared with the adjacent normal tissue from the same patient. We thus used two human NSCLC lines, A549 and Calu-3, to examine whether SEMA4b may affect the expression of MMP9 in NSCLC. We found that overexpression of SEMA4b significantly decreased MMP9 level, while SEMA4b inhibition significantly increased MMP9 level. The adapted MMP9 levels affected the potential of NSCLC invasiveness correspondingly. To define the signal transduction cascades downstream of SEMA4b for regulation of MMP9 expression, we inhibited PI3K, ERK/MAPK, or JNK signaling pathway in SEMA4b knockout NSCLC and found that only inhibition of PI3K signaling pathway significantly decreased MMP9 activation. Our data thus suggest that SEMA4b may activate PI3K signaling pathway to promote MMP9 expression, which subsequently increases metastasis of NSCLC. Our study thus highlights SEMA4b as a novel therapeutic target for NSCLC.