Circ_0003855 involvement of esophageal cancer progression through miR-622/FLOT1.

To confirm the relationship between Circ_0003855 and EC, we purchased the Human esophageal carcinoma cell line Eca109 and normal human esophageal epithelial cells HEEC, and the expression levels of Circ_0003855, miR-622, and FLOT1 were detected. The results show that Circ_0003855 and FLOT1 were highly expressed in Eca109 cells, while miR-622 was lowly expressed (p < 0.05). Subsequently, Circ_0003855 small interfering RNA (si-Circ_0003855) and its negative control (si-NC) were used to detect changes in cellular biological behaviors. We found that the activity of Eca109 cells was reduced after interfering with the expression of Circ_0003855, and miR-622 expression was elevated, while FLOT1 was decreased (p < 0.05). Additionally, si-Circ_0003855 and miR-622 inhibitor sequence (miR-622-inhibition) were co-transfected into cells with miR-622-inhibition alone, and untreated Eca109 cells were used as a control to detect the expression of FLOT1. Co-transfection of si-Circ_0003855 and miR-622-inhibition showed no significant difference in FLOT1 expression compared to the control cells (p > 0.05). Synthesizing the results of these experiments above, we believe that interfering with the expression of Circ_0003855 can inhibit the activity of EC cells, and its mechanism is related to miR-622 and FLOT1.

FLOT1 promotes gastric cancer progression and metastasis through BCAR1/ERK signaling.

Flotillin-1 (FLOT1) is a member of the flotillin family and serves as a hallmark of lipid rafts involved in the process of signaling transduction and vesicular trafficking. Here, we find FLOT1 promotes gastric cancer cell progression and metastasis by interacting with BCAR1, through ERK signaling. FLOT1 regulates BCAR1 phosphorylation and translocation. Overexpression of FLOT1 increases, while knockdown of FLOT1 decreases gastric cancer cell proliferation, migration and invasion. BCAR1 knockdown could block FLOT1 induced gastric cancer cell proliferation, migration and invasion. Re-expression of wildtype rather than mutant BCAR1 (Y410F) could partially restore FLOT1 knockdown induced gastric cancer cell migration and invasion, while the restore could be inhibited by ERK inhibitor. Furthermore, FLOT1 and BCAR1 expression is closely related to gastric cancer patients' poor outcome. Thus, our findings confirm that BCAR1 mediates FLOT1 induced gastric cancer progression and metastasis through ERK signaling, which may provide a novel pathway for gastric cancer treatment.

Comparative Study of Immunohistochemical Expression of Moesin and FLOT 1 in OSCC and Their Correlation with Histopathological Prognostic Factors.

AIM: To study immunohistochemical (IHC) expression patterns of Moesin and FLOT 1 in oral squamous cell carcinoma (OSCC) and to correlate it with histopathological prognostic factors. MATERIALS AND METHODS: A cross-sectional study design was conducted on histopathologically diagnosed cases of OSCC. The inclusion criteria were carcinoma of buccal mucosa, tongue, alveolar mucosa, palate, gingiva, the floor of the mouth, retromolar area, and soft palate. The exclusion criteria included cases of squamous cell carcinoma from sites other than the oral cavity, potentially malignant disorders (PMDs), and any pseudomalignancies of the head and neck. Tissue sections were subjected to IHC staining for Moesin and FLOT 1 and the results were subjected to statistical analysis. RESULTS: Moesin showed strong positivity and was significantly associated with the histopathological variables such as lymph nodes and the worst pattern of invasion, whereas FLOT 1 was not associated with any clinical, histopathological, or demographical variable in this study. CONCLUSION: Cytoplasmic detection of Moesin (35.19%) was higher than FLOT 1 (15.74%). There was no statistically significant relationship between the grade of the lesion and Moesin and FLOT 1. CLINICAL SIGNIFICANCE: New emerging prognostic biomarkers can aid to assess the rate of malignant transformation (epigenetic and molecular changes), thereby resulting in early prophylactic conciliation of the disease progression in OSCC. There is an urgent need for introducing these as an interventional therapy for effectively addressing OSCC at an early stage, thus preventing it from further proceeding to the advanced severe stage.

FLOT1, stabilized by WTAP/IGF2BP2 mediated N6-methyladenosine modification, predicts poor prognosis and promotes growth and invasion in gliomas.

The expression, function, and mechanism of FLOT1 (flotillin-1) remains unknown in gliomas. Here, the expression and clinical value of FLOT1 in gliomas was bioinformatically and experimentally analyzed via online omics data and local tissues. Moreover, the effects of FLOT1 depletion on cell proliferation and invasion were also detected. Besides, the underlying roles of N6-methyladenosine modification (m6A) in FLOT1 upregulation was further explored. The results demonstrated that FLOT1 was significantly upregulated in gliomas and positively correlated with advanced progression and poor prognosis of patients. FLOT1 silencing notably suppressed the cell proliferation and invasion in gliomas. The expression of WTAP and IGF2BP2was positively correlated with FLOT1 expression and served as the writer and reader of FLOT1 m6A, respectively, which stabilized FLOT1 mRNA and maintained its upregulation in gliomas. Lastly, ectopic expression of FLOT1 could notably restore the inhibitory effects caused by WTAP and IGF2BP2 depletion in glioma cells. Collectively, our results originally confirmed the upregulation and oncogenic roles of FLOT1, and revealed that WTAP/IGF2BP2 mediated m6A contributed to the upregulation of FLOT1 in gliomas, highlighting the promising application of WTAP/IGF2BP2/FLOT1 axis in target treatment of gliomas.

FLOT1 knockdown inhibits growth of AML cells through triggering apoptosis and pyroptosis.

Acute myeloid leukemia (AML) is a group of hematological malignancies characterized by clonal proliferation of immature myeloid cells. Lipid rafts are highly organized membrane subdomains enriched in cholesterol, sphingolipids, and gangliosides and play roles in regulating apoptosis through subcellular redistribution. Flotillin1 (FLOT1) is a component and also a marker of lipid rafts and had been reported to be involved in the progression of cancers and played important roles in cell death. However, the role of FLOT1 in AML remains to be explored. In this study, we found that increased expression of FLOT1 was correlated with poor clinical outcome in AML patients. Knockdown of FLOT1 in AML cells not only promoted cell death in vitro but also inhibited malignant cells engraftment in vivo. Mechanically, FLOT1 knockdown triggered apoptosis and pyroptosis. FLOT1 overexpression promoted AML cell growth and apoptosis resistance. Our findings indicate that FLOT1 is a prognostic factor of AML and may be a potential target for AML treatment.

MicroRNA­485­5p suppresses the progression of esophageal squamous cell carcinoma by targeting flotillin­1 and inhibits the epithelial­mesenchymal transition.

As esophageal squamous cell carcinoma (ESCC) is one of the most frequently diagnosed cancers in Asia, it is crucial to uncover its underlying molecular mechanisms that support its development and progression. Several articles have reported that microRNA (miR)­485­5p inhibits the malignant phenotype in a number of cancer types, such as lung, gastric and breast cancer, but to the best of our knowledge, its function in ESCC has not been studied in depth until the present study. It is of great significance to probe the regulatory action and underlying mechanism of miR­485­5p in ESCC. In brief, this study identified that miR­485­5p expression in ESCC tissues was significantly lower than that in normal tissues. The decrease in miR­485­5p expression was associated with a larger tumour size and poor histology and stage. The expression of miR­485­5p was relatively high in Eca 109 and TE­1 cells, but relatively low in KYSE 30. The overexpression of miR­485­5p inhibited cell proliferation, migration and invasion in vitro, whereas miR­485­5p knockdown did the opposite. Flotillin­1 (FLOT­1) can facilitate the malignant phenotype in various cancer types. The present study found that in ESCC tissue, the protein expression of FLOT­1 was negatively correlated with miR­485­5p expression. Further experiments showed that miR­485­5p directly targeted the 3'­untranslated region of FLOT­1. The overexpression of miR­485­5p significantly suppressed the mRNA and protein expression levels of FLOT­1, whereas knockdown had the reverse effects. Furthermore, overexpression of miR­485­5p restrained epithelial­mesenchymal metastasis (EMT)­related factors at both the mRNA and protein levels. At the same time, it also inhibited the growth of ESCC and restrained the EMT in vivo. In summary, miR­485­5p was found to be an inhibitor of ESCC and may have potential as a novel target candidate for ESCC treatment.

Long Non-Coding RNA TUG1 Promotes Cell Proliferation and Inhibits Cell Apoptosis, Autophagy in Clear Cell Renal Cell Carcinoma via MiR-31-5p/FLOT1 Axis.

PURPOSE: Clear cell renal cell carcinoma (ccRCC) is a common urological carcinoma in adults. Long non-coding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) has been reported to be involved in the progression of diverse human cancers, including renal cell carcinoma (RCC). However, the biological mechanism of TUG1 was rarely reported in ccRCC. METHODS: The levels of TUG1, microRNA miR-31-5p and flotillin 1 (FLOT1) in ccRCC tissues and cells were detected by qRT-PCR. The interactions between miR-31-5p and TUG1 or FLOT1 were predicted by starBase v2.0 and TargetScan, respectively, which were further validated by RIP assay and RNA pull-down assay. Cell counting kit-8 (CCK-8), flow cytometry and Western blot were used to assess the effects of TUG1 on cell viability, apoptosis rate and the relative protein expression levels in ccRCC cells. In addition, the xenograft tumor assay was conducted to further verify the functions of TUG1 in ccRCC in vivo. RESULTS: TUG1 was dramatically up-regulated in ccRCC tissues and cells. TUG1 silencing inhibited cell proliferation and promoted cell apoptosis, autophagy in 786-0 and A498 cells. In addition, TUG1 depletion repressed tumor growth in vivo. Moreover, miR-31-5p was validated as a direct target of TUG1, and microRNA miR-31-5p inhibitor mitigated the effects of TUG1 knockdown on ccRCC progression. Furthermore, FLOT1 was verified to be negatively interacted with miR-31-5p. FLOT1 overexpression attenuated miR-31-5p-mediated inhibitory effect on cell proliferation and promotion effects on cell apoptosis, autophagy. The restoration experiment implicated that TUG1 positively modulated FLOT1 expression by sponging miR-31-5p. CONCLUSION: All data demonstrated that TUG1 promotes cell proliferation and inhibits cell apoptosis and autophagy in ccRCC by miR-31-5p/FLOT1 axis, which may provide a therapeutic target for ccRCC patients.

MiR-1294 acts as a tumor inhibitor in cervical cancer by regulating FLOT1 expression.

Recently, important regulatory mechanisms of microRNAs (miRNAs) have been widely reported in human cancers including cervical cancer. The purpose of this study is to preliminarily clarify the function of miR-1294 in cervical cancer. The expression of miR-1294 or FLOT1 was detected using RT-qPCR or Western blot analysis. MTT, Transwell and luciferase reporter assays were used to explore the functional mechanism of miR-1294. The results showed that miR-1294 expression was decreased in cervical cancer. Functionally, overexpression of miR-1294 restrained the viability and metastasis of cervical cancer cells. MiR-1294 can also block EMT and suppress ß-catenin expression in cervical cancer cells. Additionally, FLOT1 was confirmed to be a direct target of miR-1294. The knockdown of FLOT1 impeded the progression of cervical cancer. More importantly, miR-1294 inhibited the occurrence of cervical cancer by interacting with FLOT1. In conclusion, miR-1294 inhibits cell viability, migration and invasion by suppressing FLOT1 expression.

Reduced levels of miR-485-5p in HPV-infected cervical cancer promote cell proliferation and enhance invasion ability.

Cervical cancer (CC) is the most common gynecological malignancy, with high incidence and mortality rates in China. The microRNA miR-485-5p has previously been reported to serve as a negative regulator of tumorigenesis in breast cancer and hepatocellular carcinoma, and miR-485-5p has been observed to be differentially expressed between CC and normal control tissue. Here, we confirmed that miR-485-5p expression is lower in CC than in adjacent normal tissue and proceeded to investigate the effects of miR-485 on tumor behavior in CC cell lines. We report that miR-485-5p transcription is decreased in HPV-infected CC tissue, and levels of miR-485 in clinical samples are positively correlated with the 5-year overall survival rate. The Transwell assay showed that miR-485-5p inhibited cell invasion and migration but had no influence on apoptosis and cell proliferation. Using a luciferase reporter assay, we demonstrated that miR-485-5p partially abrogated cell migration and proliferation by targeting FLOT-1 mRNA. Transfection of HPV-infected cervical carcinoma cells with an adenovirus vector encoding human FLOT-1 partially diminished the inhibitory effects of miR-485 on cell invasion. Taken, together, these data demonstrated that miR-485-5p suppresses the invasion of cancer cells by targeting FLOT-1 in HPV-infected cervical carcinoma cells.

Dynamics and Endocytosis of Flot1 in Arabidopsis Require CPI1 Function.

Membrane microdomains are nano-scale domains (10-200 nm) enriched in sterols and sphingolipids. They have many important biological functions, including vesicle transport, endocytosis, and pathogen invasion. A previous study reported that the membrane microdomain-associated protein Flotillin1 (Flot1) was involved in plant development in Arabidopsis thaliana; however, whether sterols affect the plant immunity conveyed by Flot1 is unknown. Here, we showed that the root length in sterol-deficient cyclopropylsterol isomerase 1 (cpi1-1) mutants expressing Flot1 was significantly shorter than in control seedlings. The cotyledon epidermal cells in cpi1-1 mutants expressing Flot1 were smaller than in controls. Moreover, variable-angle total internal reflection fluorescence microscopy (VA-TIRFM) and single-particle tracking (SPT) analysis demonstrated that the long-distance Flot1-GFP movement was decreased significantly in cpi1-1 mutants compared with the control seedlings. Meanwhile, the value of the diffusion coefficient G was dramatically decreased in cpi1-1 mutants after flagelin22 (flg22) treatment compared with the control seedlings, indicating that sterols affect the lateral mobility of Flot1-GFP within the plasma membrane. Importantly, using confocal microscopy, we determined that the endocytosis of Flot1-GFP was decreased in cpi1-1 mutants, which was confirmed by fluorescence cross spectroscopy (FCS) analysis. Hence, these results demonstrate that sterol composition plays a critical role in the plant defense responses of Flot1.

Moxifloxacin suppresses airway inflammation and modulates expression of caveolin-1 and flotillin-1 in airway smooth muscle cells of asthmatic rats.

BACKGROUND: Moxifloxacin (MXF) possesses anti-inflammatory properties on asthmatic airway smooth muscle cells (ASMCs) beyond their antimicrobial effects, but the mechanisms are still unknown. This study was to investigate effects of MXF on expression of caveolin-1 (Cav-1) and flotillin-1 (FLOT1) in ASMCs in asthmatic rats. METHODS: ASMCs were collected from the airway and cultured in vitro. Cells from normal rats were treated with normal saline (Group N); cells from asthmatic rats were incubated with normal saline (Group A) or MXF (20 mg/L) (Group M); Cav-1 expression was up-regulated by transferring Cav-1 expressing lentivirus (Group L) and FLOT1 expression down-regulated by using siRNA in cells from asthmatic rats (Group S). The expressions of Cav-1, FLOT1 and p65 NF-κB were measured by Western blotting and quantificational real-time polymerase chain reaction (qRT-PCR), and interleukin-8 (IL-8) and eotaxin contents were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with normal control, Cav-1 expression significantly decreased in asthmatic groups (P<0.01); MXF up-regulated Cav-1 expression in asthmatic groups (P<0.01). However, compared with normal control, the expression of FLOT1 and p65 NF-κB dramatically increased in asthmatic groups (P<0.01); MXF down-regulated the expression of FLOT1 and p65 NF-κB in asthmatic groups (P<0.01); meanwhile, the expressions of FLOT1 and p65 NF-κB decreased after up-regulation of Cav-1 expression in asthmatic groups (P=0.01). Compared with asthmatic groups, the IL-8 and eotaxin contents significantly decreased in MXF Groups, Cav-1 up-regulation asthmatic groups and FLOT1 down-regulation asthmatic groups (P<0.01). CONCLUSIONS: MXF can modulate the airway inflammation, upregulate Cav-1 expression, downregulate the expression of FLOT1 and p65 NF-κB in asthmatic rat ASMCs, which may be related to the anti-inflammatory effects of MXF in asthmatic ASMCs.

FLOT1 promotes tumor development, induces epithelial-mesenchymal transition, and modulates the cell cycle by regulating the Erk/Akt signaling pathway in lung adenocarcinoma.

BACKGROUND: FLOT1 is a scaffolding protein of lipid rafts that is believed to be involved in numerous cellular processes. However, few studies have explored the function of FLOT1 in the development of lung adenocarcinoma (LUAD) and the underlying mechanisms of FLOT1 activity. METHODS: FLOT1 knockdown and overexpression models were constructed via lentivirus. Cell growth, invasion, migration, and apoptosis were detected to evaluate the role of FLOT1 in LUAD development. Epithelial-mesenchymal transition (EMT) and cell cycle regulatory markers were then examined. Finally, the influence of FLOT1 on the Erk/Akt signaling pathway was investigated. RESULTS: FLOT1 promoted cell growth, invasion, and migration and inhibited cell apoptosis. In addition, FLOT1 induced EMT and modulated the cell cycle by activating the Erk/Akt signaling pathway. CONCLUSION: The findings indicate a significant role of FLOT1 in LUAD development. Targeting FLOT1 may be a potential therapeutic strategy for LUAD.

Characterization of the epithelial membrane protein 3 interaction network reveals a potential functional link to mitogenic signal transduction regulation.

Epithelial Membrane Protein 3 (EMP3), a 4-transmembrane glycoprotein, first gained attention as a putative tumor suppressor. Accumulating evidence, however, points to a more tumor promotive function of EMP3. The biological function of EMP3 remains largely unclear. To elucidate more of EMP3's interaction network, we performed a Yeast-Two-Hybrid (Y2H) screening, followed by validation of candidate interactors by Biomolecular Fluorescence Complementation (BiFC) and Proximity Ligation Assay (PLA). Furthermore, we generated stable EMP3 knockdown cell lines and measured cell proliferation, migration and sensitivity to apoptosis induction as well as the expression and activation levels of important signal pathway components. The Y2H screening yielded 10 novel interactions of EMP3, eight of which could also be detected by BiFC and PLA interaction assays. All newly discovered interaction partners are involved in signaling or trafficking regulation. Most notably, FLOT1 and HTATIP2 have well described roles in the regulation of EGFR signaling. In addition, knockdown of EMP3 resulted in reduced levels of p-AKT, p-ERK and p-EGFR, attenuated cell proliferation and migration and sensitized cells to apoptosis induction by TRAIL and Staurosporine. Based on these observations we hypothesize that EMP3 might be involved in the regulation of receptor-tyrosine-kinase mediated mitogenic signaling.

HOTAIR/miR-214-3p/FLOT1 axis plays an essential role in the proliferation, migration, and invasion of hepatocellular carcinoma.

BACKGROUND: Long non-coding RNA (lncRNA) Hox transcript antisense intergenic RNA (HOTAIR) has been reported to play an important role in hepatocellular carcinoma (HCC) progression. Although there is evidence on HOTAIR being associated with HCC progression, the underlying mechanism remains to be further clarified. METHODS: HOTAIR, miR-214-3p and FLOT1 expression were measured by quantitative real-time PCR or western blot. Cell proliferation, migration, and invasion were displayed by transwell assay, MTT, and colony formation assay. The relationship between HOTAIR, miR-214-3p, and FLOT1 was investigated by luciferase reporter assay. Tumor suppressive effect of HOTAIR was displayed by HepG2 xenografting to nude mice. RESULTS: HOTAIR and FLOT1 expression were significantly up-regulated, whereas miR-214-3p was obviously down-regulated. Also, down-regulation of HOTAIR and FLOT1 as well as up-regulation of miR-214-3p inhibited cell proliferation, invasion, and migration. Intriguingly, the effects of miR-214-3p overexpression on HCC cells were rescued by high expression of HOTAIR. Otherwise, HOTAIR regulated FLOT1 expression through targeting miR-214-3p in HCC cells. Simultaneously, low HOTAIR expression inhibited FLOT1 expression by up-regulating miR-214-3p, which suppressed tumor growth in vivo. CONCLUSION: HOTAIR expression indirectly regulated FLOT1 expression through endogenous competition with miR-214-3p. HOTAIR/miR-214-3p/FLOT1 axis affected the cell proliferation, migration, and invasion of HCC.

Mechanism of lentivirus mediated flot1 gene expression on invasion and apoptosis of gastric cancer cells / 中国药学杂志

OBJECTIVE: To investigate inhibitory effect of FLOT1 gene expression on invasion and apoptosis of gastric cancer cells. METHODS: The designed FLOT1 siRNA lentiviral vector (si-FLOT1 group) was transfected into human gastric cancer MKN-45 cells, at the same time, the negative control lentivirus vector (negative group) was transfected, and the blank group was set up. Western blotting was used to detect the expression of FLOT1, E-cadherin, α-SMA, cleaved caspase 3, Bcl-2 and Bax proteins. After cells were transfected for 24, 48, 72 and 96 h, cell viability was detected by CCK-8 assay. After cells were transfected for 48 h, transwell chamber, flow cytometry and DCFH-DA assay were used to detect the invasiveness, apoptosis rate and ROS content, respectively. RESULTS: FLOT1 siRNA lentiviral vector inhibited significantly the expression of FLOT1 in MKN-45 cells, which was significantly different from the blank group (P<0.05). Compared with si-FLOT1 group and the blank group, the cell vitality decreased, the invasion ability decreased, the apoptosis rate increased, the expression of E-cadherin, cleaved caspase 3 and Bax protein increased, the expression of α-SMA and Bcl-2 protein decreased, and the content of ROS increased, and the difference was statistically significant (P<0.05). CONCLUSION: Down regulation of FLOT1 gene expression can reduce the invasiveness of gastric cancer cells by inhibiting EMT, and promote apoptosis by regulating the expression of apoptosis related proteins and increasing the ROS content of cells.

The dynamics and endocytosis of Flot1 protein in response to flg22 in Arabidopsis.

Membrane microdomains play vital roles in the process of bacterial infection. The membrane microdomain-associated protein Flot1 acts in an endocytic pathway and is required for seedling development, however, whether Flot1 is a part of host defense mechanisms remains unknown. During an analysis of callose deposition, we found that Flot1 amiRNAi mutants exhibited defects in response to flg22. Using variable-angle total internal reflection fluorescence microscopy (VA-TIRFM), structured illumination microscopy (SIM) and fluorescence cross spectroscopy (FCS), we determined that the dynamic behavior of GFP-Flot1 in Arabidopsis thaliana cotyledon epidermal cells changed significantly in plants treated with the elicitor flg22. Moreover, we found that Flot1 was constitutively recycled via an endocytic pathway and that flg22 could promote endocytosis. Importantly, targeting of Flot1 to the late endosome/vacuole for degradation increased in response to flg22 treatment; immunoblot analysis showed that when triggered by flg22, GFP-Flot1 was gradually degraded in a time-dependent manner. Taken together, these findings support the hypothesis that the changing of dynamics and oligomeric states can promote the endocytosis and degradation of Flot1 under flg22 treatment in plant cells.

MicroRNA-608 inhibits proliferation of bladder cancer via AKT/FOXO3a signaling pathway.

BACKGROUND: Current evidence indicates that miR-608 is widely down-regulated in various malignant tumors including liver cancer, colon cancer, lung cancer and glioma, and acts as a tumor suppressor by inhibiting cell proliferation, invasion and migration or by promoting apoptosis. The specific biological function of miR-608 in bladder cancer is still unknown. METHODS: qRT-PCR and Chromogenic in Situ Hybridization (CISH) was conducted to assess the expression of miR-608 in paired BCa tissues and adjacent non-tumor bladder urothelial tissues. Bisulfite sequencing PCR was used for DNA methylation analysis. CCK-8, colony formation and flow cytometry assays were performed, and a xenograft model was studied. Immunohistochemistry staining was performed with peroxidase and DAB. The target of miR-608 was validated with a dual-luciferase reporter assay, quantitative RT-PCR, and Western blotting. RESULTS: miR-608 is frequently down-regulated in human BCa tissues. The methylation status of CpG islands is involved in the regulation of miR-608 expression. Overexpression of miR-608 inhibits the proliferation and tumorigenesis of BCa cells in vitro and in vivo. Additionally, up-regulation of miR-608 in BCa cells induces G1-phase arrest through AKT/FOXO3a signaling. In contrast, down-regulation of miR-608 promotes proliferation and cell cycle progression in BCa cells. Moreover, the expression of FLOT1 was directly inhibited by miR-608, the down-regulation of FLOT1 induced by siFLOT1 could be significantly reversed by miR-608 inhibitor. Similarly, the up-regulation of FLOT1 by FLOT1 overexpression plasmid (pFLOT1) could also reverse the suppressed cell proliferation caused by miR-608. CONCLUSIONS: miR-608 is a potential tumor suppressor in BCa, and the restoration of miR-608 might be a promising therapeutic option for BCa.

miRNA-target network reveals miR-124as a key miRNA contributing to clear cell renal cell carcinoma aggressive behaviour by targeting CAV1 and FLOT1.

Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor with frequent metastatic rate and poor survival. Integrated analyses allow understanding the interplay between different levels of molecular alterations.We integrated miRNA and gene expression data from 458 ccRCC and 254 normal kidney specimens to construct a miRNA-target interaction network.We identified the downregulated miR-124-3p, -30a-5p and -200c-3p as the most influential miRNAs in RCC pathogenesis.miR-124-3p and miR-200c-3p expression showed association with patient survival, miR-30a-5p was downregulated in metastases compared to primary tumors. We used an independent set of 87 matched samples for validation. We confirmed the functional impact of these miRNAs by in vitro assays. Restoration of these miRNAs reduced migration, invasion and proliferation. miR-124-3p decreased the S phase of cell cycle, as well. We compared transcriptome profiling before and after miRNA overexpression, and validated CAV1 and FLOT1 as miR-124-3p targets. Patients with higher CAV1 and FLOT1 had lower miR-124-3p expression and shorter overall survival.We hypothesize that these three miRNAs are fundamental contributing to ccRCC aggressive/metastatic behavior; and miR-124-3p especially has a key role through regulating CAV1 and FLOT1 expression. Restoration of the levels of these miRNAs could be considered as a potential therapeutic strategy for ccRCC.

miR-485-5p acts as a negative regulator in gastric cancer progression by targeting flotillin-1.

MicroRNAs (miRNAs) play important roles in cancer progression including gastric cancer. miR-485-5p is reported as a potential suppressor in breast cancer, but its expression, cellular function and clinic features in gastric cancer is not known. In our study, we found that miR-485-5p expression was down-regulated in gastric cancer cell lines. miR-485-5p could inhibit gastric cancer cell growth in vitro and in vivo. We also found that miR-485-5p suppressed gastric cancer cell metastasis and sphere formation. It was confirmed flotillin-1 (Flot1) as a direct target of miR-485-5p, and up-regulation of miR-485-5p could decrease expression of Flot1 in gastric cancer cells. Further investigation showed that ectopic expression of Flot1 partially reversed the inhibition effect of enforced miR-485-5p expression on the malignant phenotypes of gastric cancer cells. The low expression of miR-485-5p in gastric cancer tissues was related to advanced clinical features and poorer prognosis. Our study suggested that miR-485-5p could be a potential prognostic marker and functions as a tumor suppressor in human gastric cancer by post-transcriptionally targeting Flot1.

Prognostic significance of Flotillin1 expression in clinically N0 tongue squamous cell cancer.

PURPOSE: The present study aimed to investigate the clinical and prognostic significance of Flotillin1 (FLOT1) in clinically N0 tongue squamous cell cancer (cN0 TSCC). METHODS: Real-time PCR and Western blotting analyses were carried out to examine FLOT1 expression in four tongue squamous cell cancer cell lines, primary cultured normal tongue epithelial cells, and eight matched pairs of oral tongue cancer samples and adjacent non-cancerous tissue samples from the same patient. Immunohistochemistry was performed to examine FLOT1 protein expression in paraffin-embedded tissues from 181 cN0 TSCC patients. Statistical analyses evaluated the diagnostic value and the associations of FLOT1 expression with clinical parameters. RESULTS: FLOT1 mRNA and protein levels were upregulated in tongue squamous cell cancer cell lines and cancerous tissues compared with that in TEC and adjacent non-cancerous tissue samples. The level of FLOT1 protein was positively correlated with clinical stage (P = 0.001), T classification (P = 0.009), N classification (P = 0.001) and recurrence (P = 0.018). Patients with higher FLOT1 expression had shorter overall survival times. CONCLUSION: Our results suggest that overexpression of FLOT1 can be found in patients with higher pathological stage, T classification, N classification or recurrence. FLOT1 expression is associated with cN0 TSCC progression and may be valuable for the prognostic evaluation of cN0 TSCC.