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Abstract Lung adenocarcinoma (LAC) is one of the most common pulmonary adenocarcinomas with a high peak of mortality, and metastasis is the main culprit of LAC deaths. microRNAs play important role in cancer metastasis, and thus are regarded as potential diagnostic and prognostic markers for human cancers. However, many miRNAs exhibit dual roles in diverse cellular contexts. Here, we revealed that hsa‐miR‐335, a previously reported tumor suppressor, exhibited an oncogenic role in LAC. Overexpression of miR‐335 enhanced the abilities of A549 and H1299 cells to invade and migrate by regulating epithelial‐mesenchymal transition, while inhibition of miR‐335 exhibited an opposite effect in vitro and in vivo. Mechanically, miR‐335 inhibited the expression of Copine‐1 (CPNE1), an NF‐κB suppressor, through interacting with its mRNA 3′UTR, while mutating the binding sites abolished this inhibitory effect. This finding not only highlights the suppressive effect of CPNE1 on cell motility, but also provides new insight into miR‐335 in promoting LAC metastasis.

Abstract Background Metastasis is a leading cause of breast cancer mortality. The induction of epithelial-to-mesenchymal transition (EMT) and complex oncogenic signaling is a vital step in the evolution of highly metastatic and therapeutically-intractable breast cancer; necessitating novel target discovery or development of therapeutics that target metastatic breast cells (MBCs). Methods To achieve this, this study employs a combination of in silico bioinformatics analyses, protein and transcript analyses, drug sensitivity assays, functional assays and animal studies. Results The present study identified CDH11 as an inductor and/or facilitator of metastatic signaling, and biomarker of poor prognosis in MBCs. Furthermore, we showed that in the presence of CDH11-rich cancer-associated fibroblasts (CAFs), MCF7 and MDA-MB-231 MBC cell lines acquired enhanced metastatic phenotype with increased CDH11, β-catenin, vimentin, and fibronectin (FN) expression. We also demonstrated, for the first time to the best of our knowledge that exposure to anti-CDH11 antibody suppresses metastasis, reduces CDH11, FN and β-catenin expression, and abrogate the cancer stem cell (CSC)-like traits of MBC cells. Interestingly, ectopic expression of miR-335 suppressed CDH11, β-catenin and vimentin expression, in concert with attenuated metastatic and CSC potentials of the MBC cells; conversely, inhibition of miR-335 resulted in increased metastatic potential. Finally, corroborating the in silica and in vitro findings, in vivo assays showed that the administration of anti-CDH11 antibody or miR-335 mimic suppressed tumorigenesis and inhibited cancer metastasis. Conclusions These findings validate our hypotheses that miR-335 mediates anti-CDH11 antibody therapy response and that an enhanced miR-335/CDH11 ratio elicits marked suppression of the MBC CSC-like and metastatic phenotypes, thus revealing a therapeutically-exploitable inverse correlation between CDH11-enhanced CSC-like and metastatic phenotype and miR-335 expression in MBCs. Thus, we highlight the therapeutic promise of humanized anti-CDH11 antibodies or miR-335-mimic, making a case for their clinical application as efficacious therapeutic option in patients with MBC.

An association was found between reduced expression of miR-34a, miR-146a with both metastasis to regional lymph nodes (relative risk RR=10.50 and RR=5.25, respectively) and the development of distant metastases (RR=9.50 and RR=4, 40, respectively) in gastric cancer. They are excellent classifiers: AUC>0.9 for both miRNAs. The association of miR-335 expression with metastasis to the lymph nodes is much weaker, but it is also a good classifier for identifying a group with distant metastasis (RR=5.90). A correlation was found between the expression of miR-34a and miR-146a during metastasis, which is absent in non-metastatic tumors. Thus, miR-34a, miR-146a, and miR-335 miRNAs can be proposed as candidates for biomarkers of the risk of gastric cancer metastasis. [ABSTRACT FROM AUTHOR]

Background: Long noncoding RNAs (lncRNAs) are known as key regulators in many cancer types, but their biological functions in nasopharyngeal carcinoma (NPC) remain largely unknown. In the present study, we aim to explore the role of the lncRNA ZNRD1-AS1 in NPC tumor development. Methods: The role of ZNRD1-AS1 in NPC tissues and cells was explored by using quantitative real-time PCR assay. Cellular behavioral experiments were used in testing NPC cell proliferation, invasion, and migration. Luciferase reporter assay, RNA-binding protein immunoprecipitation, and Western blot analysis were used in estimating the associations among ZNRD1-AS1, miR-335, and ROCK1. Results: ZNRD1-AS1 expression was elevated in the NPC tissues and cells, and ZNRD1-AS1 overexpression was positively correlated with advanced TNM stage and the presence of lymph node metastasis. Our biological experiments indicated that ZNRD1-AS1 knockdown reduces NPC cell invasion and metastasis. Further analyses revealed that ZNRD1-AS1 as a ceRNA promotes the migration and invasion of NPC cells by sponging miR-335. We provided evidence that ZNRD1-AS1 facilitates the invasion and metastasis of NPC cells via the miR-335–ROCK1 axis. Conclusion: Our data shed light on the oncogenic role of ZNRD1-AS1 in NPC tumor development, and a promising therapeutic target for NPC was identified. [ABSTRACT FROM AUTHOR]

Abstract Background Multiple aberrant microRNA expression has been reported in gastric cancer. Among them, microRNA-335-5p (miR-335), a microRNA regulated by DNA methylation, has been reported to possess both tumor suppressor and tumor promoter activities. Results Herein, we show that miR-335 levels are reduced in gastric cancer and significantly associate with lymph node metastasis, depth of tumor invasion, and ultimately poor patient survival in a cohort of Amerindian/Hispanic patients. In two gastric cancer cell lines AGS and, Hs 746T the exogenous miR-335 decreases migration, invasion, viability, and anchorage-independent cell growth capacities. Performing a PCR array on cells transfected with miR-335, 19 (30.6%) out of 62 genes involved in metastasis and tumor invasion showed decreased transcription levels. Network enrichment analysis narrowed these genes to nine (PLAUR, CDH11, COL4A2, CTGF, CTSK, MMP7, PDGFA, TIMP1, and TIMP2). Elevated levels of PLAUR, a validated target gene, and CDH11 were confirmed in tumors with low expression of miR-335. The 3′UTR of CDH11 was identified to be directly targeted by miR-335. Downregulation of miR-335 was also demonstrated in plasma samples from gastric cancer patients and inversely correlated with DNA methylation of promoter region (Z = 1.96, p = 0.029). DNA methylation, evaluated by methylation-specific PCR assay, was found in plasma from 23 (56.1%) out of 41 gastric cancer patients but in only 9 (30%) out of 30 healthy donors (p = 0.029, Pearson’s correlation). Taken in consideration, our results of the association with depth of invasion, lymph node metastasis, and poor prognosis together with functional assays on cell migration, invasion, and tumorigenicity are in accordance with the downregulation of miR-335 in gastric cancer. Conclusions Comprehensive evaluation of metastasis and invasion pathway identified a subset of associated genes and confirmed PLAUR and CDH11, both targets of miR-335, to be overexpressed in gastric cancer tissues. DNA methylation of miR-335 may be a promissory strategy for non-invasive approach to gastric cancer.

LncRNA LINC01510 (LINC01510) was a newly identified tumor-related lncRNA whose dysregulation and potential function have been reported in several tumors. However, the expression, clinical significances, and action mechanisms of LINC01510 in papillary thyroid carcinoma (PTC) are still unclear. In this study, we firstly reported that LINC01510 was highly expressed in both PTC tissues and cell lines. Additionally, we used dual-luciferase reporter assay and confirmed that SOX2 could bind directly to the LINC01510 promoter region, activating its transcription. Functional assays with a series of cell experiments indicated that knockdown of LINC01510 suppressed the proliferation, migration and invasion of SW1736 and TPC-1 cells. Moreover, down-regulation of LINC01510 resulted in accelerated apoptosis by promoting the expression of Caspase3/9. In particular, LINC01510 acted as an endogenous sponge by directly binding miR-335, resulting in the suppression of miR-335 expressions. Besides, we confirmed that SHH was a target of miR-335 and miR-335 over-expression distinctly reduced SHH expression in PTC cells. Finally, in the cytoplasm, we provided evidenced that LINC01510 acted as a sponge for miR-335, reducing its ability to promote SHH expression. In addition, the results of Western blot indicated that knockdown of LINC01510 inhibited the expression of SHH and GLI1, suggesting that Hedgehog pathway was suppressed. Taken together, our findings revealed that the newly identified LINC01510/miR-335/SHH axis could be a therapeutic target for PTC. • LINC01510 expression induced by SOX2 was upregulated in both papillary thyroid carcinoma tissues and cell lines. • Knockdown of LINC01510 suppressed the proliferation and metastasis of papillary thyroid carcinoma cells. • LINC01510 acted as a sponge for miR-335, modulating miR-335/SHH and Hedgehog pathway. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are key regulators in the development and progression of osteosarcoma (OS). Based on our previous microarray data, we found that miR-335 expression was downregulated in OS tissue relative to normal tissue. Herein, we further found that miR-335 was downregulated in OS cell lines relative to the osteoblastic cell line hFOB 1.19. Further functional experiments found that upregulation of miR-335 suppressed the proliferation, invasion and migration of OS cells in vitro and tumor growth and lung metastasis in vivo. In addition, the expression of a total of 750 mRNAs was decreased upon the upregulation of miR-335, and SNIP1 was found to be the direct target of miR-335. Restoration of SNIP1 expression attenuated the suppressive effect of miR-335 on OS cells. Additionally, miR-335 suppressed the mRNA and protein expression of SNIP1, MMP-2, and MMP-7 in vitro and in vivo. MiR-335 also suppressed c-Myc and NFκb p65 in vitro and in vivo. In conclusion, our data suggest that miR-335 plays a significant role in the tumorigenesis and metastasis of OS and may serve as a therapeutic target for OS treatment. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are small noncoding RNAs that exert their functions by targeting specific mRNA sequences. Many studies have demonstrated that miRNAs are crucial for cancer progression, during which they can act as either oncogenes or tumor suppressors. Previous research has shown that miR-335 is downregulated in breast cancer, and it has been shown to be a breast cancer suppressor. In addition, emerging evidence indicates that erythropoietin-producing hepatocellular A4 (EphA4) is implicated in cancer cell proliferation, migration, and invasion. However, little is known about the relationship between miR-335 and EphA4 in breast cancer. In the present study, we used bioinformatic and biochemical analyses to demonstrate that EphA4 is a direct downstream target of miR-335 in human breast cancer MCF-7 and MDA-MB-23 cells and revealed that miR-335 negatively regulates the expression of EphA4 in these cells. Further investigation revealed that miR-335 overexpression inhibits MCF-7 and MDA-MB-231 cell proliferation and that this inhibition is attenuated by EphA4 coexpression. Similarly, miR-335 overexpression also inhibited growth and downregulated EphA4 expression in tumors in nude mice. Moreover, our results demonstrated that miR-335 overexpression suppresses migration and invasion in MCF-7 and MDA-MB-231 cells, an effect that was reversed by EphA4 overexpression. These findings confirmed that EphA4 is a direct target gene of miR-335 and that miR-335 suppresses breast cancer cell proliferation and motility in part by directly inhibiting EphA4 expression. [ABSTRACT FROM AUTHOR]

Background: Multiple aberrant microRNA expression has been reported in gastric cancer. Among them, microRNA-335-5p (miR-335), a microRNA regulated by DNA methylation, has been reported to possess both tumor suppressor and tumor promoter activities. Results: Herein, we show that miR-335 levels are reduced in gastric cancer and significantly associate with lymph node metastasis, depth of tumor invasion, and ultimately poor patient survival in a cohort of Amerindian/Hispanic patients. In two gastric cancer cell lines AGS and, Hs 746T the exogenous miR-335 decreases migration, invasion, viability, and anchorage-independent cell growth capacities. Performing a PCR array on cells transfected with miR-335, 19 (30.6%) out of 62 genes involved in metastasis and tumor invasion showed decreased transcription levels. Network enrichment analysis narrowed these genes to nine (PLAUR, CDH11, COL4A2, CTGF, CTSK, MMP7, PDGFA, TIMP1, and TIMP2). Elevated levels of PLAUR, a validated target gene, and CDH11 were confirmed in tumors with low expression of miR-335. The 3'UTR of CDH11 was identified to be directly targeted by miR-335. Downregulation of miR-335 was also demonstrated in plasma samples from gastric cancer patients and inversely correlated with DNA methylation of promoter region (Z = 1.96, p = 0.029). DNA methylation, evaluated by methylation-specific PCR assay, was found in plasma from 23 (56.1%) out of 41 gastric cancer patients but in only 9 (30%) out of 30 healthy donors (p = 0.029, Pearson's correlation). Taken in consideration, our results of the association with depth of invasion, lymph node metastasis, and poor prognosis together with functional assays on cell migration, invasion, and tumorigenicity are in accordance with the downregulation of miR-335 in gastric cancer. Conclusions: Comprehensive evaluation of metastasis and invasion pathway identified a subset of associated genes and confirmed PLAUR and CDH11, both targets of miR-335, to be overexpressed in gastric cancer tissues. DNA methylation of miR-335 may be a promissory strategy for non-invasive approach to gastric cancer. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs are emerging as new players in gene regulation, but whether long non-coding RNAs influence the expression of microRNA is unclear. The expression levels of misato family member 2, pseudogene were significantly associated with lymphatic metastasis and distal metastasis in 80 paired gastric cancer tissues using real-time quantitative reverse transcription polymerase chain reaction experiments. The effects of long non-coding RNA misato family member 2, pseudogene were assessed by overexpressing or downexpressing long non-coding RNA misato family member 2, pseudogene in gastric cancer cells. Long non-coding RNA misato family member 2, pseudogene promoted gastric cancer cell growth, colony formation, migration, and invasion in gastric cancer cells. Long non-coding RNA misato family member 2, pseudogene influenced biologic functions in gastric cancer cells via indirectly regulating the activation of miR-335. Our results reveal long non-coding RNA misato family member 2, pseudogene as an oncogenic long non-coding RNA that promotes cell growth and invasion. Therefore, long non-coding RNAs might function as key regulatory hubs in gastric cancer progression. [ABSTRACT FROM AUTHOR]

Purpose: One of the advanced cancer therapy strategies is immune-stimulating compound based immunotherapy Staphylococcal enterotoxin B (SEB) is one of the potent superantigens, which can efficiently activate antitumor immune response to eradicate tumor growth and inhibit metastasis. Herein, we evaluated the effect of SEB on the expression of two master microRNAs, mir-335 and mir-10b, involved in metastasis. Methods: A metastatic breast cancer cell line MDA-MB231was treated with four different concentrations of SEB, including 10, 102, 103 and 104 ng/ml, for 24 and 48 hours. To identify the cytotoxic effect of SEB, treated cells were examined by MTT assay. The stem loop RT-PCR (TaqMan) was used to analyze the mir-335 and mir-10b expression. Results: Results showed that SEB significantly increased the expression of mir-335 both after 24 and 48 hours (pv < 0.001 and pv < 0.05, respectively). No significant differences were found in the mir-10b expression. Conclusion: Moreover, our findings demonstrated no cytotoxic effect of SEB on the treated cells. Our results suggest that SEB probably induces its anti-metastatic effect via the expression regulation of the main genes which contributes to metastasis. [ABSTRACT FROM AUTHOR]

Metastasis is the leading cause of death in patients with breast cancer and aberrantly expressed microRNAs (miRNAs) are highly associated with this process. A previous study has shown that miR-335 is downregulated in breast cancer and can suppress tumor invasion and metastasis. Emerging evidences indicate that c-Met is implicated in cell scattering, migration, and invasion. However, little is known about the relationship between miR-335 expression and c-Met alteration in breast cancer. In the present study, we found that miR-335 expression was downregulated and c-Met protein expression was upregulated in two human breast cell lines. MiR-335 was found to negatively regulate c-Met protein level by directly targeting its 3′ untranslated region (UTR). Forced expression of miR-335 decreased c-Met expression at protein levels and consequently diminished hepatocyte growth factor (HGF)-induced phosphorylation of c-Met and subsequently inhibited HGF promotion of breast cancer cell migration in a c-Met-dependent manner. MiR-335 expression was increased after 5-aza-2′-deoxycytidine (5-AZA-CdR) treatment, and 5-AZA-CdR treatment resulted in the same phenotype as the effect of miR-335 overexpression. Taken together, these results demonstrate that miR-335 suppresses breast cancer cell migration by negatively regulating the HGF/c-Met pathway. [ABSTRACT FROM AUTHOR]

MicroRNAs have been suggested to play a vital role in regulate tumor progression and invasion. However, the expression of miR-335 in colorectal cancer (CRC) and its clinical significance are not known. Here, we report that miR-335 is a tumor suppressor by regulating expression of ZEB2. In this study, we showed that downregulated miR-335 levels in highly invasive CRC cell lines and tissues. Kaplan-Meier survival analysis indicated that patients with reduced miR-335 had a poor overall survival. Furthermore, enhancing the expression of miR-335 inhibited CRC cell migration and invasion in vitro and lung and liver metastasis in vivo, while silencing its expression resulted in increased migration and invasion. Additionally, we identified a novel miR-335 target, ZEB2, and the direct interaction between them was verified by 3′-untranslated region dual-luciferase reporter assay. In conclusion, our results demonstrate that miR-335 functions as a tumor suppressor and play a role in inhibiting metastasis of CRC cells through targeting ZEB2. These findings suggest that miR-335 may be useful as a new potential therapeutic target for CRC. [ABSTRACT FROM AUTHOR]

Post-transcriptional regulators have emerged as robust effectors of metastasis and display deregulated expression through unknown mechanisms. Here, we reveal that the human microRNA-335 locus undergoes genetic deletion and epigenetic promoter hypermethylation in every metastatic derivative obtained from independent patients' malignant cell populations. Genetic deletion of miR-335 is a common event in human breast cancer, is enriched for in breast cancer metastases, and also correlates with ovarian cancer recurrence. We furthermore identify miR-335 as a robust inhibitor of tumor reinitiation. We thus implicate the miR-335 locus on 7q32.2 as the first selective metastasis suppressor and tumor initiation suppressor locus in human breast cancer. [ABSTRACT FROM AUTHOR]