HRD1 Promotes Non-small Cell Lung Carcinoma Metastasis by Blocking Autophagy-mediated MIEN1 Degradation

Dysregulation of autophagy has been implicated in the development of many diseases, including cancer. Here, we revealed a novel function of the E3 ubiquitin ligase HRD1 in non-small cell lung carcinoma (NSCLC) metastasis by regulating autophagy. Mechanistically, HRD1 inhibits autophagy by promoting ATG3 ubiquitination and degradation. Additionally, a pro-migratory and invasive factor, MIEN1 (migration and invasion enhancer 1), was found to be autophagically degraded upon HRD1 deficiency. Importantly, both HRD1 and MIEN1 expression are upregulated and positively correlated in lung tumors. Based on these results, we proposed a novel mechanism of HRD1 function that the degradation of ATG3 protein by HRD1 leads to autophagy inhibition and MIEN1 release, thus promoting NSCLC metastasis. Therefore, our findings provided new insights into the role of HRD1 in NSCLC metastasis and new therapeutic targets for lung cancer treatment.

MiR-124-5p Inhibits the Progression of Gastric Cancer by Targeting MIEN1

Objective:

To observe the effect of miR-124-5p on progression of gastric cancer (GC) and explore the targeting mechanism.

Methods:

After collecting the specimens, we used real-time fluorescence quantitative PCR to detect the miR-124-5p level of GC tissue and corresponding adjacent tissue. Then MTT test and scratch wound-healing assay were hired to evaluate the influence of miR-124-5p in GC cell (SGC-803 and SGC7901) migration and proliferation ability. The binding of miR-124-5p to migration and invasion enhancer 1 (MIEN1) was detected through dual luciferase reporter gene experiment and western blot was utilized to assay the protein level of MIEN1.

Results:

Compared with adjacent tissues, miR-124-5p level in GC tissues was lower significantly. MiR-124-5p mimic inhibited the metastasis and proliferation ability of SGC7901 cells and miR-124-5p inhibitor promoted the migration and proliferation ability of SGC803 cells. In addition, miR-124-5p targeted MIEN1 and negatively modulated the MIEN1 expression in SGC-803 and SGC7901 cells. Silencing MIEN1 negatively regulated the metastasis and proliferation ability of SGC7901 cells.

Conclusion:

MiR-124-5p inhibited the GC cell proliferation and metastasis phenotypes through MIEN1, which probably becomes a novel molecular target for clinical GC treatment.

CircRNA_100876 sponges miR-136 to promote proliferation and metastasis of gastric cancer by upregulating MIEN1 expression

Previous reports have revealed that circRNA_100876 was extremely important in the progression of triple-negative breast cancer. Nevertheless, the mechanism towards the role of circRNA_100876 in Gastric cancer (GC) remains unknown. Here, we determined circRNA_100876 expression by quantitative real-time PCR (qRT-PCR) in twenty pairs of GC tissues and adjacent tissues. Our data indicated that the expression of circRNA_100876 was raised in GC tissues. In vitro, functional experiments confirmed that cell proliferation, invasion along with migration was promoted by circRNA_100876 in GC tissues. Simultaneously, relative luciferase assay uncovered that circRNA_100876 functioned as a sponge for miR-136, followed by retarding miR-136-induced inhibited effects on the corresponding target, MIEN1. Moreover, we revealed that the expression of MIEN1 was up-regulated and correlated to much worse prognosis of GC. Collectively, our data identified that the promotion of GC growth and metastasis induced by circRNA_100876 interacted with miR-136 and MIEN1, indicating an emerging announcement for uncovering the potential mechanism of GC progression.

Migration and Invasion Enhancer 1 Is an NF-ĸB-Inducing Gene Enhancing the Cell Proliferation and Invasion Ability of Human Prostate Carcinoma Cells In Vitro and In Vivo

Migration and invasion enhancer 1 (MIEN1) is a membrane-anchored protein and exists in various cancerous tissues. However, the roles of MIEN1 in prostate cancer have not yet been clearly addressed. We determined the expression, biological functions, and regulatory mechanisms of MIEN1 in the prostate. The results of immunohistochemical analysis indicated that MIEN1 was expressed specifically in epithelial cells and significantly higher in adenocarcinoma as compared to in normal tissues. MIEN1 enhanced in vitro cell proliferation, invasion, and in vivo tumorigenesis. Meanwhile, MIEN1 attenuated cisplatin-induced apoptosis in PC-3 cells. Overexpression of NF-ĸB-inducing kinase (NIK) enhanced MIEN1 expression, while overexpression of NF-ĸB inhibitor α (IĸBα) blocked MIEN1 expression in PC-3 cells. In prostate carcinoma cells, MIEN1 provoked Akt phosphorylation; moreover, MIEN1 downregulated N-myc downstream regulated 1 (NDRG1) but upregulated interleukin-6 (IL-6) gene expression. MK2206, an Akt inhibitor, impeded the modulation of MIEN1 on NDRG1 and IL-6 expressions. Our studies suggest that MIEN1 is an NF-ĸB downstream oncogene in the human prostate. Accordingly, the modulation of Akt signaling in the gene expressions of NDRG1 and IL-6 may account for the functions of MIEN1 in cell proliferation, invasion, and tumorigenesis in prostate carcinoma cells.

Emerging Role of Migration and Invasion Enhancer 1 (MIEN1) in Cancer Progression and Metastasis

Tumor metastasis is a sequential event accounting for numerous cancer-related fatalities worldwide. The process of metastasis serially involves invasion, intravasation, extravasation, and tumor growth at the secondary site. Migration and invasion enhancer 1 (MIEN1) is a membrane associated protein overexpressed in various human cancers. Biological activity of MIEN1 is driven by geranylgeranyltransferase-I mediated prenylation at CAAX motif and methylation of the prenylated protein that anchors MIEN1 into the cellular membrane. Post-translationally modified MIEN1 interacts with Syk kinase and Annexin A2 protein; polymerizes G-actin and stabilizes F-actin filament; induces focal adhesion kinase phosphorylation and decrease cofilin phosphorylation implicated in both invasion and metastasis of different cancer types. In the present review, we discuss the structure, function, and involvement of MIEN1 in cancer progression. We also highlight the future prospects of MIEN1 as an emerging molecule and novel target in cancer cell invasion and metastasis.

Emerging targets in cancer drug resistance

Drug resistance is a complex phenomenon that frequently develops as a failure to chemotherapy during cancer treatment. Malignant cells increasingly generate resistance to various chemotherapeutic drugs through distinct mechanisms and pathways. Understanding the molecular mechanisms involved in drug resistance remains an important area of research for identification of precise targets and drug discovery to improve therapeutic outcomes. This review highlights the role of some recent emerging targets and pathways which play critical role in driving drug resistance.

MIEN1 is tightly regulated by SINE Alu methylation in its promoter

Migration and invasion enhancer 1 (MIEN1) is a novel gene involved in prostate cancer progression by enhancing prostate cancer cell migration and invasion. DNA methylation, an important epigenetic regulation, is one of the most widely altered mechanisms in prostate cancer. This phenomenon frames the basis to study the DNA methylation patterns in the promoter region of MIEN1. Bisulfite pyrosequencing demonstrates the MIEN1 promoter contains a short interspersed nuclear Alu element (SINE Alu) repeat sequence. Validation of methylation inhibition on MIEN1 was performed using nucleoside analogs and non-nucleoside inhibitors and resulted in an increase in both MIEN1 RNA and protein in normal cells. MIEN1 mRNA and protein increases upon inhibition of individual DNA methyltransferases using RNA interference technologies. Furthermore, dual luciferase reporter assays, in silico analysis, and chromatin immunoprecipitation assays identified a sequence upstream of the transcription start site that has a site for binding of the USF transcription factors. These results suggest the MIEN1 promoter has a SINE Alu region that is hypermethylated in normal cells leading to repression of the gene. In cancer, the hypomethylation of a part of this repeat, in addition to the binding of USF, results in MIEN1 expression.

MIEN1 drives breast tumor cell migration by regulating cytoskeletal-focal adhesion dynamics

Migration and invasion enhancer 1 (MIEN1) is an important regulator of cell migration and invasion. MIEN1 overexpression represents an oncogenic event that promotes tumor cell dissemination and metastasis. The underlying mechanism by which MIEN1 regulates migration and invasion has yet to be deciphered. Here, we demonstrate that MIEN1 acts as a cytoskeletal-signaling adapter protein to drive breast cancer cell migration. MIEN1 localization is concentrated underneath the actin-enriched protrusive structures of the migrating breast cancer cells. Depletion of MIEN1 led to the loss of actin-protrusive structures whereas the over-expression of MIEN1 resulted in rich and thick membrane extensions. Knockdown of MIEN1 also decreased the cell-substratum adhesion, suggesting a role for MIEN1 in actin cytoskeletal dynamics. Our results show that MIEN1 supports the transition of G-actin to F-actin polymerization and stabilizes F-actin polymers. Additionally, MIEN1 promotes cellular adhesion and actin dynamics by inducing phosphorylation of FAK at Tyr-925 and reducing phosphorylation of cofilin at Ser-3, which results in breast cancer cell migration. Collectively, our data show that MIEN1 plays an essential role in maintaining the plasticity of the dynamic membrane-associated actin cytoskeleton, which leads to an increase in cell motility. Hence, targeting MIEN1 might represent a promising means to prevent breast tumor metastasis.

miR-136 targets MIEN1 and involves the metastasis of colon cancer by suppressing epithelial-to-mesenchymal transition

MIEN1 is a novel oncogene, and it involves tumor progression in various cancer types, including colon cancer. However, the definite molecular mechanisms of MIEN1 in colon cancer progression remain to be completely elucidated. In the present study, bioinformatics prediction showed that miR-136 could be an upstream regulator of MIEN1; a luciferase assay and Western blot assay revealed that miR-136 negatively regulates MIEN1 expression via directly targeting its 3'-untranslated region sequence. Moreover, a functional assay using wound healing and transwell invasion showed that overexpressed miR-136 inhibited cell migration and invasion, and overexpression of MIEN1 partly rescued the above-mentioned effects of miR-136 in colon cancer cells. Additionally, a clinical sample assay showed that miR-136 expression was generally downregulated in colon cancer tissue, which was inversely correlated with MIEN1 expression. Furthermore, we found that miR-136 suppressed the Akt/NF-κB signaling pathway and epithelial-to-mesenchymal transition in colon cancer. These results suggest that miR-136, as a tumor suppressor, acts in tumor metastasis by suppressing MIEN1 expression in colon cancer, providing a novel target for the treatment of colon cancer.

MIEN1 promotes oral cancer progression and implicates poor overall survival

Oral squamous cell carcinoma is a highly malignant tumor with the potential to invade local and distant sites and promote lymph node metastasis. Major players underlying the molecular mechanisms behind tumor progression are yet to be fully explored. Migration and invasion enhancer 1 (MIEN1), a novel protein overexpressed in various cancers, facilitates cell migration and invasion. In the present study we investigated the expression and role of MIEN1 in oral cancer progression using an in vitro model, patient derived oral tissues and existing TCGA data. Expression analysis using immortalized normal and cancer cells demonstrated increased expression of MIEN1 in cancer. Assays performed after MIEN1 knockdown in OSC-2 cells showed decreased migration, invasion and filopodia formation; while MIEN1 overexpression in DOK cells increased these characteristics and also up-regulated some Akt/NF-κB effectors, thereby suggesting an important role for MIEN1 in oral cancer progression. Immunohistochemical staining and analyses of oral tissue specimens, collected from patients over multiple visits, revealed significantly more staining in severe dysplasia and squamous cell carcinoma compared to mildly dysplastic or hyperplastic tissues. Finally, this was corroborated with the TCGA dataset, where MIEN1 expression was not only higher in intermediate and high grade cancer with significantly lower survival but also correlated with smoking. In summary, we demonstrate that MIEN1 expression not only positively correlates with oral cancer progression but also seems to be a critical molecular determinant in migration and invasion of oral cancer cells, thereby, playing a possible role in their metastatic dissemination.

Association analysis of ERBB2 amplicon genetic polymorphisms and STARD3 expression with risk of gastric cancer in the Chinese population

The purpose of this study was to investigate whether risk of gastric cancer (GC) was associated with single nucleotide polymorphisms (SNPs) in a gene cluster on the chromosome 17q12-q21 (ERBB2 amplicon) in the Chinese Han population. We detected twenty-six SNPs in this gene cluster containing steroidogenic acute regulatory-related lipid transfer domain containing 3 (STARD3), protein phosphatase 1 regulatory subunit 1B (PPP1R1B/DARPP32), titin-cap (TCAP), per1-like domain containing 1(PERLD1/CAB2), human epidermal growth factor receptor-2 (ERBB2/HER2), zinc-finger protein subfamily 1A 3 (ZNFN1A3/IKZF3) and DNA topoisomerase 2-alpha (TOP2A) genes in 311 patients with GC and in 425 controls by Sequenom. We found no associations between genetic variations and GC risk. However, haplotype analysis implied that the haplotype CCCT of STARD3 (rs9972882, rs881844, rs11869286 and rs1877031) conferred a protective effect on the susceptibility to GC (P=0.043, odds ratio [OR]=0.805, 95% confidence intervals [95% CI]=0.643-0.992). The STARD3 rs1877031 TC genotype endued histogenesis of gastric mucinous adenocarcinoma and signet-ring cell carcinoma (P=0.021, OR=2.882, 95% CI=1.173-7.084). We examined the expression of STARD3 in 243 tumor tissues out of the 311 GC patients and 20 adjacent normal gastric tissues using immumohistochemical (IHC) analysis and tissue microarrays (TMA). The expression of STARD3 was observed in the gastric parietal cells and in gastric tumor tissues and significantly correlated with gender (P=0.004), alcohol drinking (P<0.001), tumor location (P=0.007), histological type (P=0.005) and differentiation (P=0.023) in GC. We concluded that the combined effect of haplotype CCCT of STARD3 might affect GC susceptibility. STARD3 expression might be related to the tumorigenesis of GC in the Chinese population.