BACKGROUND: Breast cancer is the most common cancer among women worldwide, and approximately 70% of breast cancers are hormone receptor-positive and express estrogen receptor-α (ERα) or/and progesterone receptor. ERα has been identified to promote the growth of primary breast cancer, however, it can also antagonize signaling pathways that lead to epithelial-mesenchymal transition (EMT), including transforming growth factor-β (TGF-β) signaling. miRNA alteration or dysfunction is involved in cancer development and progression. Although miR-1271 has identified as a tumor suppressor in various cancers, the role of miR-1271 in breast cancer is still limited.
METHODS: The effect of miR-1271 on breast cancer progression was investigated both in vitro and in vivo. The EMT-related protein expression levels and localization were analyzed by western blotting and immunofluorescence, respectively. Chromatin immunoprecipitation and dual-luciferase reporter assays were used to validate the regulation of ERα-miR-1271-SNAI2 feedback loop.
RESULTS: miR-1271 suppresses breast cancer progression and EMT phenotype both in vitro and in vivo by targeting SNAI2. Estrogen reverses TGF-β-induced EMT in a miR-1271 dependent manner. Furthermore, ERα transactivates the miR-1271 expression and is also transcriptionally repressed by SNAI2.
CONCLUSIONS: Our data uncover the ERα-miR-1271-SNAI2 feedback loop and provide a mechanism to explain the TGF-β network in breast cancer progression.

MicroRNAs (miRNAs) have been demonstrated to regulate the progression of numerous types of cancer, including acute myeloid leukemia (AML). Previous studies demonstrated that miR‑1271‑5p functions as a tumor suppressor; however, the roles of miR‑1271‑5p in AML remain unknown. In the present study, miR‑1271‑5p was significantly downregulated in AML tissues compared with normal tissues by reverse transcription‑quantitative polymerase chain reaction analysis. Furthermore, the expression levels of miR‑1271‑5p in patients with AML may function as a prognostic marker. In addition, overexpression of miR‑1271‑5p significantly suppressed the proliferation and induced apoptosis of AML cells by Cell Counting kit‑8 and fluorescence activated cell sorter assays; miR‑1271‑5p downregulation exhibited opposing effects. Additionally, transcription factor ZIC2 may be a direct target of miR‑1271‑5p in AML cells, which was demonstrated by a luciferase reporter assay and RNA pulldown assay. Overexpression of miR‑1271‑5p significantly reduced the mRNA and protein expression levels of ZIC2 in AML193 and OCI‑AML2 cells by reverse transcription‑quantitative polymerase chain reaction analysis and western blotting. Furthermore, an inverse correlation between miR‑1271‑5p and ZIC2 expression in AML samples was observed. In summary, ZIC2 was upregulated in AML tissues, and restoration of ZIC2 expression was able to promote the proliferation and reduce the apoptosis of AML cells transfected with miR‑1271‑5p mimics. The results of the present study demonstrated that miR‑1271‑5p inhibited the progression of AML by targeting ZIC2.

MicroRNAs (miRNAs) have been reported to exert important effects on the initiation, progression and metastasis of glioblastoma multiforme (GBM). In this study, we aimed to explore the regulation role of miR-1271 on the development of GBM. We found that miR-1271 was a Bcl-2-targeting miRNA, and the levels of miR-1271was decreased in samples from patients with GBM, compared with those from corresponding normal tissue samples. On the other hand, the levels of miR-1271 were inversely related to the levels of Bcl-2, which have been significantly increased in GBM samples. The overall survival was poorer in patients with low levels of miR-1271, compared to those with high levels of miR-1271. In vitro, the chemo-resistant cell survival mediated with Bcl-2 was inhibited by overexpression of miR-1271 and was enhanced by depletion of miR-1271. Thus, the chemo-resistance of GBM cells may be promoted after suppressing miR-1271 through cell survival mediated with Bcl-2. The prognosis of patients with GBM receiving chemotherapy may be improved by overexpressing miR-1271 in cancerous cells.

Emodin has a direct inhibitory effect on the growth and metastasis of a variety of malignant tumor cells. MicroRNA‑1271 (miR‑1271) has an extensive tumor‑suppression effect by inhibiting epithelial mesenchymal transition (EMT) in tumor cells and induces tumor cell apoptosis. Proceeding with the EMT regulatory mechanism of pancreatic carcinoma, the present study aimed to examine the inhibitory effect of miR‑1271 and emodin against invasion and metastasis of pancreatic carcinoma. The expression of EMT‑related markers (E‑cadherin, ZEB1 and TWIST1) was analyzed by western blotting. mRNA levels of miR‑1271, E‑cadherin, ZEB1 and TWIST1 in pancreatic tumor cells (SW1990) were measured through reverse transcription‑quantitative polymerase chain reaction and cell invasiveness was detected using Transwell assays. In addition, a liver metastatic model was established with an implantation of pancreatic tumor tissue into the spleens of nude mice to study the effect of emodin on pancreatic cancer liver metastasis. In the present study, it was demonstrated that miR‑1271 significantly decreased in pancreatic cancer cells and tissues. Twist1 may be a target gene of miR‑1271. Emodin could inhibit the proliferation ability of pancreatic cancer cells and increased miR‑1271 expression level. Further, we found that miR‑1271 significantly inhibited SW1990 cell EMT and invasive ability. We also provided the evidence that emodin inhibited SW1990 cell EMT by raising the level of miR‑1271. Moreover, the in vivo experiments have verified the inhibiting effect of emodin against liver metastasis of pancreatic cancer. The data in the present study indicated that emodin inhibited pancreatic cancer EMT and invasion by increasing the content of miR‑1271.

MicroRNAs (miRNAs or miRs) have been shown to regulate hepatocellular carcinoma (HCC) metastasis. In the present study, we focused on the functions of miR-1271 in HCC metastasis. The downregulation of miR-1271 was found to be associated with to venous infiltration, an advanced TNM stage (III+IV stage) and a shorter survival time. Our in vitro and in vivo data demonstrated that miR-1271 prevented HCC cell migration and invasion, as well as the formation of lung metastatic clusters. In addition, miR-1271 was demonstrated to markedly inhibit the epithelial-mesenchymal transition (EMT) of HCC cells. Importantly, protein tyrosine phosphatase type IVA member 1 (PTP4A1) was identified as a direct downstream target of miR-1271 in HCC. Furthermore, we confirmed that the phosphorylation of c-Src at Tyr416 mediated by PTP4A1 was a potential anti-HCC mechanism of action of miR-1271. On the whole, our data indicate that miR-1271 inhibits HCC metastasis by targeting the PTP4A1/c-Src signaling pathway and may serve as a prospective cancer therapeutic target for HCC.

Accumulating evidence has suggested that calpain small subunit 1 (Capn4) plays an important role in the development and progression of malignant tumors. However, little is known about the role of Capn4 in colorectal cancer (CRC). In this study, we aimed to investigate the potential role of Capn4 in CRC and the regulation of Capn4 by microRNAs (miRNAs). Here, we found that Capn4 expression was highly up-regulated in CRC cell lines. Knockdown of Capn4 by siRNA significantly inhibited the proliferation and invasion of CRC cell lines. Furthermore, knockdown of Capn4 suppressed Wnt signaling in CRC cells. Interestingly, Capn4 was found to be a target gene of miR-1271, a tumor suppressive miRNA. The results showed that miR-1271 negatively regulated Capn4 expression in CRC cells. An inverse correlation between miR-1271 and Capn4 was also shown in CRC clinical tissues. Moreover, the overexpression of miR-1271 suppressed the proliferation, invasion and Wnt signaling of CRC cells. Importantly, we found that the restoration of Capn4 expression significantly reversed the antitumor effects of miR-1271 in CRC cells. Overall, these results suggest that miR-1271 inhibits the proliferation and invasion of CRC cells by down-regulating Capn4. Our study suggests that Capn4 and miR-1271 may serve as potential therapeutic targets for the treatment of CRC.

Recent studies have reported an important role for microRNA-1271 (miR-1271) in tumorigenesis. However, the role of miR-1271 in colorectal cancer remains unknown. Here, we found that miR-1271 was significantly decreased in colorectal cancer tissues and cell lines. Overexpression of miR-1271 inhibited cell proliferation, colony formation, cell invasion, and induced cell cycle arrest in colorectal cancer cells. Metadherin (MTDH) was identified as a target gene of miR-1271. Moreover, miR-1271 negatively regulated MTDH expression in colorectal cancer cells and reversely correlated with MTDH expression in colorectal cancer specimens. Additionally, miR-1271 also regulated the activation of Wnt signaling in colorectal cancer cells. The restoration of MTDH expression significantly reversed the antitumor effect of miR-1271 in colorectal cancer cells. These findings indicate an important role for miR-1271/MTDH in the tumorigenesis of colorectal cancer, and suggest that miR-1271 may be a novel therapeutic target for colorectal cancer.

Colorectal cancer (CRC) cells undergo apoptosis in the presence of the small-molecule inhibitor ABT-263 by up-regulating antiapoptotic Bcl-2 family members. However, the resistance to ABT-263 gradually developed in most solid tumors due to its low affinity to Mcl-1. Here, we found the BET-Bromodomain inhibitor JQ1, when combined with ABT-263, synergistically reduced Mcl-1 protein level, induced apoptosis, and decreased cell viability in the CRC HCT-15, HT-29 and SW620 cells. The subsequent mechanism study revealed that a pathway of c-Myc/miR-1271-5p/Noxa/Mcl-1 underlies the synergistic effect of such combination treatment. We discovered that miR-1271-5p, the key mediator for the synergistic effect, is transcriptionally activated by c-Myc, and binds to the 3'-UTR of noxa to inhibit its protein production. The combination treatment of JQ1 and ABT-263 inhibited c-Myc protein level and also c-Myc-driven expression of miR-1271-5p, subsequently increased the protein level of Noxa, and finally promotes the degradation of Mcl-1. Our findings provide an alternative strategy to resolve the resistance during treatment of CRC by JQ1, and also discovered a novel miR-1271-5p-dependent regulatory mechanism for gene expression of noxa.

OBJECTIVE: Endometrial carcinoma (EC) is one of the most common female malignancies worldwide. Growing evidence showed that microRNAs (miRNAs) are involved in the EC progression. The present study aimed to investigate the role of miR-1271 in the development and progression of EC.
PATIENTS AND METHODS: The EC tissues and adjacent normal tissues were obtained from 42 EC patients. The expression of miR-1271 in EC tissues and cells was examined using Real-time RT-PCR. Western blot was used to quantify the level of cyclin-dependent kinase 1 (CDK1) in EC tissues and cells lines. Cell proliferation, colony formation and flow cytometry were done to examine effects on cancer cell proliferation and apoptosis in vitro. Bioinformatics software was used to predict some potential target genes of miR-1271. Besides, the dual luciferase reporter gene assay was used to determine the direct targeting relationship between miR-1271 and CDK1.
RESULTS: MiR-1271 was significantly downregulated in human EC tissues and cells while CDK1 was strongly upregulated. Bioinformatics analysis indicated that CDK1 was a potential target of miR-1271. Then, luciferase reporter assay confirmed that CDK1 was a direct target gene of miR-1271. In vitro studies showed that miR-1271 overexpression reduced EC cell proliferation and promoted apoptosis, while restoration of CDK1 attenuated these effects of miR-1271 on EC cells. Moreover, we found that knockdown of miR-1271 significantly promoted EC cell growth and suppressed apoptosis.
CONCLUSIONS: Our findings showed that miR-1271 served as a tumor suppressor in EC via targeting CDK1, suggesting miR-1271 as a new potential target for therapy strategy in EC.

The dysregulation of transcription factors contributes to the unlimited growth of cancer cells. Zic2 has been shown to be crucial to the progression of human cancers. However, its role in hepatocellular carcinoma (HCC) remains unclear. Our data showed that Zic2 expression gradually increased from normal to cancer to metastatic tissues. Zic2 overexpression promoted, whereas Zic2 knockdown inhibited, cell proliferation and migration in vitro as well as tumor growth and metastasis in vivo. Gene microarray results indicated that PAK4 was a potential target of Zic2. The knockdown of Zic2 decreased, whereas Zic2 re-expression increased, the expression of PAK4. ChIP and luciferase assays indicated that Zic2 directly bound to the PAK4 promoter and modulated its activity. PAK4 interference attenuated Zic2-mediated cell growth via modulating the Raf/MEK/ERK pathway. In a cohort of 615 patients, Zic2 was positively correlated with PAK4 and associated with worse overall and disease-free survival. Multivariate analyses revealed that Zic2 and PAK4 were independent indicators of a poor outcome in HCC. In addition, Zic2 expression was inversely correlated with miR-1271 expression. Re-introduction of miR-1271 attenuated Zic2-promoted cell proliferation and migration. Taken together, our findings suggest that the newly identified miR-1271/Zic2/PAK4 axis plays an important role in HCC progression and may serve as a potential therapeutic target for HCC.

ETS-related gene (ERG) is an oncogene that is commonly found in prostate cancer (PCa). Several miRNAs have been reported to be associated with PCa. This study was undertaken to identify miRNAs that act as a tumor suppressor by targeting ERG. We collected 70 PCa and paired adjacent non-tumor (Adjacent-N) tissues and analyzed ERG expression by immunohistochemistry(IHC). Expression of 6 miRNAs (miR-21,-34a,-96,-125b,-150 and miR-1271) was analyzed by qRT-PCR. Luciferase reporter assay was performed to examine miRNA binding to the 3'-UTR of target genes. The effects of ectopic expression of miRNA on cell growth and MAPK signaling pathway were investigated in in PC-3 and LNCaP cell lines. Among 70 PCa cases, 13 (18.6%) were ERG positive. No significant difference of miR-34a, 96, 125b, and 150 expression was found between PCa and Adjacent-N tissues. Significantly higher level of miR-21 and lower level of miR-1271 expression were found in cancer tissues. Furthermore, miR-1271 was down-regulated in ERG-positive PCa cases (p < 0.05). Based on luciferase reporter assay, we identified ERG gene as a direct target gene for miR-1271. Transfection of a miR-1271 mimics into PC-3 and LNCaP cells repressed the ERG expression and significantly suppressed cell growth. Lastly, ectopic expression of miR-1271 inhibits AKT1, p38gama and CREB kinase activity. Our results suggested that reduced expression of miR-1271 may be involved in the ERG expression and that miR-1271 could be a therapeutic target for ERG-positive prostate cancer patients.

miR-1271 is a multifunctional post-translational modulator, which is involved in several diseases. However, the association between microRNA (miR)‑1271 and fibronectin 1 (FN1) remains to be fully elucidated in neuroglioma. In the present study, it was hypothesized that a post‑translational mechanism of miR‑1271 regulates the expression of FN1 in the progression of neuroglioma. The present study aimed to investigate the clinical significance and underlying molecular mechanisms of miRNA‑1271 in the development of glioma. The miR‑1271 levels in glioma tissues and cell lines were assessed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). miR‑1271 mimics and inhibitors were transfected to gain or loss of miR‑1271 function. Cell proliferation was analyzed by using an MTT assay. The targeted genes were predicted by a bioinformatics algorithm and confirmed by a dual luciferase reporter assay. The mRNA and protein levels were assessed by RT‑qPCR and western blotting. The results showed that miR‑1271 was downregulated in glioma tumor tissues and cell lines. In addition, it was demonstrated that low levels of miR‑1271 in patients with glioma were correlated with low survival rate. In vitro, the cell viability was significantly suppressed following transfection with miRNA‑1271 mimics and increased following transfection with the miRNA‑1271 inhibitor. The miRNA‑1271 mimics induced cell apoptosis and the miRNA‑1271 inhibitor suppressed cell apoptosis in H4 and U251 cell lines. Furthermore, the 3'‑untranslated region of FN1 was bound by miR‑1271. Therefore, it was concluded that miR‑1271 inhibited glioma cell growth by targeting FN1, and a low level of miR‑1271 in glioma tumor tissues was associated with lower survival rates in patients with glioma.

The forkhead transcription factor FOXK2 has been implicated in the progression of human cancers, but its role and clinical significance in hepatocellular carcinoma (HCC) have not been explored. Here we showed that FOXK2 expression was increased and associated with tumor size, TNM stage and vascular invasion. High FOXK2 expression was correlated with poor overall and disease-free survival in two independent cohorts consisting of 864 patients with HCC. The prognostic value of FOXK2 was validated by stratified survival analyses in subgroups difined by factors contributing to worse survival. Multivariate Cox regression model revealed that FOXK2 served as an independent factor for overall survival. The FOXK2 expression was reversely connected with miR-1271-5p in clinical samples. Re-introduction of miR-1271 decreased FOXK2 at both mRNA and protein levels. Luciferase assay confirmed that FOXK2 was a direct target of miR-1271 in HCC cells. Overexpression of FOXK2 enhanced the cell growth and migration, whereas FOXK2 silence resulted in the opposite phenotypes. Further studies demonstrated that FOXK2 exerted oncogenic activity via activation of PI3K/AKT signaling pathway. Collectively, our data suggest FOXK2 as an oncogene and a promising prognostic biomarker in HCC. Targeting the newly identified miR-1271/FOXK2/AKT axis may represent a potential strategy for HCC intervention.

Increasing evidence suggests that numerous fork-head transcription factors are required to repress the mammalian cells phenotype. Among them, Foxk2 is a ubiquitously expressed family member, but the role of Foxk2 in mediating tumor metastasis in non-small cell lung cancer has not been explored. In this investigation reduced Foxk2 expression was found in lung adenocarcinoma tissues compared with the adjacent non-tumor tissues, and was associated with better overall survival. Low expression was also found in the NSCLC cell lines such as A549, NCI-H520, H1299, H358 and H460 cells. Recombinant lentivirus expressing Foxk2 constructs or ShFoxk2 were developed and transfected into A549 cells or NCI-H520 cells, immunofluorescence assay, qRT-PCR, and western blot analysis were used to measure the change of the epithelial markers, E-cadherin and α-catenin, and mesenchymal markers N-cadherin and vimentin. Wound healing assay and Transwell assay were used to measure the relative cell invasion ability. MTT assay, Edu assay, and cell cycle distribution analysis were used to confirm the effect of Foxk2 on cell proliferation. ChIP-seq, qChIP, as well as luciferase reporter gene assays were used to detect the target genes regulated by Foxk2, Bioinformatics predicated the potential miRNAs that could target Foxk2. Our study demonstrated that Foxk2 played major roles in NSCLC EMT by directly targeting N-cadherin and Snail, we found that Foxk2 regulated NSCLC cell growth by suppressing the expression of cyclin D1 and CDK4, which suggested that Foxk2 might be a multifunctional regulator in NSCLC. The expression of Foxk2 may be regulated by miR-1271, which could serve as a promising therapeutic target for NSCLC.

Disheveled-Axin domain containing 1 (DIXDC1) is involved in the development and progression of multiple cancers. However, the function significance of DIXDC1 in prostate cancer remains unclear. In this study, we investigated the function of DIXDC1 in prostate cancer and the regulation of DIXDC1 by microRNAs (miRNAs). We found that DIXDC1 was highly expressed in prostate cancer cells. Knockdown of DIXDC1 by small interfering RNAs markedly suppressed proliferation, invasion and Wnt signaling in prostate cancer cells. DIXDC1 was identified as a target gene of miR-1271 by bioinformatics analysis, dual-luciferase reporter assay, real-time quantitative polymerase chain reaction and Western blot analysis. Furthermore, DIXDC1 expression was inversely correlated with miR-1271 expression in prostate cancer tissues. The overexpression of miR-1271 significantly inhibited proliferation, invasion and Wnt signaling in prostate cancer cells. However, the inhibition of miR-1271 exhibits the opposite effects. Moreover, the overexpression of DIXDC1 significantly reversed the inhibitory effects of miR-1271 overexpression. Taken together, our results suggest that DIXDC1 plays an important role in regulating prostate cancer cell proliferation and invasion. Targeting DIXDC1 by miR-1271 may be a promising therapeutic strategy for prostate cancer.

MicroRNAs (miRNAs) have emerged as important regulators in multiple myeloma (MM). miR-1271 is a tumor suppressor in many cancer types. However, the biological role of miR-1271 in MM remains unclear. In the present study, we elucidated the biological role of miR-1271 in MM. Results showed that miR-1271 was significantly decreased in primary MM cells from MM patients and MM cell lines. Overexpression of miR-1271 inhibited proliferation and promoted apoptosis of MM cells. Conversely, suppression of miR-1271 showed the opposite effect. Bioinformatics algorithm analysis predicted that smoothened (SMO), the activator of Hedgehog (HH) signaling pathway, was a direct target of miR-1271 that was experimentally verified by a dual-luciferase reporter assay. Furthermore, overexpression of miR-1271 inhibited SMO expression and HH signaling pathway. Conversely, the restoration of SMO expression markedly abolished the effect of miR-1271 overexpression on cell proliferation, apoptosis and HH signaling pathway in MM cells. Taken together, the present study suggests that miR-1271 functions as a tumor suppressor that inhibits proliferation and promotes apoptosis of MM cells through inhibiting SMO-mediated HH signaling pathway. This finding implies that miR-1271 is a potential therapeutic target for the treatment of MM.

Dietary saturated fatty acids (SFA) in excess not only induce hepatic insulin resistance, but also result in type 2 diabetes (T2DM). Although microRNAs (miRNAs) participate widely in the pathogenesis of a range of diseases through the suppression of target gene expression at the post-transcriptional level, the implications of SFA-induced miRNAs in the dysregulation of metabolism, particularly in the development of insulin resistance, are largely unclear. SFA palmitate provoked an impairment of insulin signaling in HepG2 cells via a reduction in the expression of INSR and IRS-1 protein. The significant upregulation of miR-1271, which was presumed to target INSR and IRS-1 3'UTRs, was observed in the palmitate-treated HepG2 cells. Using a reporter gene assay, miR-1271 authentically targeted the 3'UTRs of INSR and IRS-1. Furthermore, the overexpression of miR-1271 caused a substantial decrease in INSR and IRS-1 expression, which led to an impairment in insulin signaling and glycogen metabolism. Therefore, these findings suggest that the induction of miR-1271 by SFA palmitate promotes the development of insulin resistance by targeting INSR and IRS-1 in hepatocytes.

Pancreatic cancer (PC) remains one of the most lethal types of cancer in adults. The purpose of this study was to determine the role of miR-1271 in regulation of epithelial mesenchymal transition (EMT) and metastasis of pancreatic cancer cells. miR-1271 was identified to be significantly down-regulated in PC tissues by miRNA array. Also, an increase of EMT-regulators ZEB1 and TWIST1 expression level is accompanied by a decrease of miR-1271. We showed that expression of miR-1271 was significantly down-regulated in PC tissues as compared with that in normal tissues. In addition, our results showed that miR-1271 expression levels were decreased while ZEB1 and TWIST1 expression levels were increased in detected PC cell lines. Moreover, ectopic expression of miR-1271 suppressed and antagomiR-1271 promoted proliferation, migration, and invasion in SW1990 and PANC-1 cells. Bioinformatics coupled with luciferase and Western blot assays also revealed that miR-1271 inhibited expression of ZEB1 and TWIST1, which are master regulators of tumor metastasis. Our study first indicates that miR-1271 functions as a suppressor in regulating of pancreatic cancer EMT by targeting ZEB1 and TWIST1, and it promise as a therapeutic target and prognostic marker for metastatic pancreatic cancer.

BACKGROUND: Ovarian cancer is the most lethal gynecological malignant cancer in the female genital system. The dysfunction of miRNA contributes to ovarian cancer development.
MATERIAL AND METHODS: The miR-1271 level in ovarian cancer tissues and cells was assayed by qRT-PCR. The miR-1271 expression in cells was overexpressed by miRNA-mimic transfection and reduced by miRNA-antisense-oligonucleotide (ASO) transfection. Cell proliferation was analyzed by an MTT assay. The targeted genes were predicted by a bioinformatics algorithm and confirmed by a dual luciferase reporter assay. The protein level was assayed by Western blotting.
RESULTS: The ovarian cancer tissue and cell lines showed low levels of miR-1271. Low levels of miR-1271 in ovarian cancer tissues were correlated with a low rate of patient survival, and the overexpression of miR-1271 inhibited the proliferation of ovarian cancer cells. The 3' UTR of cyclin G1 (CCNG1) was targeted by miR-1271.
CONCLUSIONS: Low levels of miR-1271 in ovarian cancer tissues promoted cancer cell growth. MiR-1271 may be a new predictor of prognosis in ovarian cancer. MiR-1271 exerted its role by targeting CCNG1.

BACKGROUND/AIMS: FOXQ1 overexpression has been reported to enhance tumor growth and invasion. However, the biological function of FOXQ1 and the mechanism underlying its upregulation in gastric cancer (GC) remain unknown.
METHODS: QPCR was used to detect the expression of miR-1271 and FOXQ1 in specimens from GC patients. FOXQ1-siRNA, and miR- 1271 mimics and inhibitor were transfected into human MGC-803 and SGC-7901 cells. The transwell assay was used to examine the cell invasive ability. The regulation mechanism was confirmed by luciferase reporter assay. Markers of epithelial-mesenchymal transition (EMT) were detected by western blot analysis.
RESULTS: MiR-1271 was downregulated in both GC tissues and GC cell lines. The expression of miR-1271 was inversely correlated with tumor size (P = 0.017), tumor stage (P = 0.035), lymph node metastasis (P = 0.018), and TNM stage (P = 0.025). Ectopic expression of miR-1271 dramatically suppressed GC cell proliferation, invasion, and EMT. Furthermore, FOXQ1 was identified as a direct target of miR-1271. Knockdown of FOXQ1 inhibited GC cell malignant behavior, whereas FOXQ1 overexpression partially restored the suppression effects of miR-1271. Additionally, miR-1271 expression was negatively correlated with FOXQ1 in GC tissues.
CONCLUSIONS: MiR-1271 inhibits cell proliferation, invasion, and EMT in GC by directly suppressing FOXQ1 expression.

BACKGROUND: Recently, there has been increasing attention on the role of microRNAs (miRNAs) in cancer development. Several expression profiling studies have provided evidence of aberrant expression of miRNAs in prostate cancer and have highlighted the potential use of specific miRNA expression signatures as prognostic or predictive markers. Here we report an expression analysis of miR-1247-5p, miR-1249, miR-1269a, miR-1271-5p, miR-1290, miR-1291, and miR-1299.
METHODS: qRT-PCR was performed to validate the differential expression of miRNAs in clinical samples, and the effect of miR-1247-5p was studied in prostate cancer cell lines transiently transfected with a miR-1247-5p mimic. The expression of miR-1247-5p's putative target MYCBP2 was evaluated by qRT-PCR and Western blotting, and the interaction of the miRNA with the target gene was assessed using a luciferase assay.
RESULTS: We found a significant up-regulation of miR-1247-5p in castration-resistant prostate cancer (CRPC) samples compared to non-malignant prostate. The expression of miR-1247-5p was subsequently studied in prostate cancer (PC) cell lines where an up-regulation of miR-1247-5p was observed in the androgen-independent PC-3 model. Target prediction analysis for miR-1247-5p performed online revealed that MYCBP2 (myc-binding protein 2) was a high-scoring potential target. Functional studies in vitro performed using PC-3 and LNCaP models confirmed the down-regulation of MYCBP2 at the mRNA and protein levels, and a luciferase assay showed interaction between the miRNA and target gene.
CONCLUSION: miR-1247-5p is overexpressed in CRPC and targets MYCBP2.

MicroRNAs (miRNAs) are short, non-coding RNAs (∼ 22 nt) that play important roles in the pathogenesis of human diseases by negatively regulating numerous target genes at posttranscriptional level. However, the role of microRNAs in lung cancer, particularly non-small-cell lung cancer (NSCLC), has remained elusive. In this study, two microRNAs, miR-1271 and miR-628, and their predicted target genes were identified differentially expressed in NSCLC by analyzing the miRNA and mRNA expression data from NSCLC tissues and their matching normal controls. miR-1271 and its target gene HOXA5 were selected for further investigation. CCK-8 proliferation assay showed that the cell proliferation was promoted by miR-1271 in NSCLC cells, while miR-1271 inhibitor could significantly inhibited the proliferation of NSCLC cells. Interestingly, migration and invasion assay indicated that overexpression of miR-1271 could significantly promoted the migration and invasion of NSCLC cells, whereas miR-1271 inhibitor could inhibited both cell migration and invasion of NSCLC cells. Western blot showed that miR-1271 suppressed the protein level of HOXA5, and luciferase assays confirmed that miR-1271 directly bound to the 3'untranslated region of HOXA5. This study indicated indicate that miR-1271 regulates NSCLC cell proliferation and invasion, via the down-regulation of HOXA5. Thus, miR-1271 may represent a potential therapeutic target for NSCLC intervention.

Numerous studies showed that drug resistance of gastric cancer cells could be modulated by the abnormal expression of microRNAs (miRNAs) which target multiple cell signaling pathways. The possible function of miR-1271 in the formation of cisplatin resistance in gastric cancer cells has been investigated in this study. miR-1271 was significantly down-regulated in gastric cancer tissues and various gastric cancer cell lines. Moreover, it was down-regulated in the cisplatin-resistant gastric cancer cell line SGC7901/cisplatin (DDP) and the down-regulation of miR-1271 in SGC7901/DPP cells was accompanied by the up-regulation of insulin-like growth factor 1 receptor (IGF1R)/insulin receptor substrate 1 (IRS1) pathway-related proteins, i.e., IGF1R, IRS1, serine/threonine-protein kinase mTOR (mTOR), and the apoptosis regulator Bcl-2 (BCL2), compared with the parental SGC7901 cells. Over-expression of miR-1271 sensitized SGC7901/DDP cells to cisplatin. Changes in the luciferase activity of reporter constructs harboring the 3'-untranslated region of the above proteins in SGC7901/DDP cells suggested that IGF1R, IRS1, mTOR, and BCL2 were target genes of miR-1271. Enforced miR-1271 expression repressed the protein levels of its targets, inhibited proliferation of SGC7901/DDP cells, and sensitized SGC7901/DDP cells to DDP-induced apoptosis. Overall, on the basis of the results of our study, we proposed that miR-1271 could regulate cisplatin resistance in human gastric cancer cells, at least partially, via targeting the IGF1R/IRS1 pathway.

Epithelial ovarian cancer (EOC) is the most common gynecologic malignancy. To identify the micro-ribonucleic acids (miRNAs) expression profile in EOC tissues that may serve as a novel diagnostic biomarker for EOC detection, the expression of 1722 miRNAs from 15 normal ovarian tissue samples and 48 ovarian cancer samples was profiled by using a quantitative real-time polymerase chain reaction (qRT-PCR) assay. A ten-microRNA signature (hsa-miR-1271-5p, hsa-miR-574-3p, hsa-miR-182-5p, hsa-miR-183-5p, hsa-miR-96-5p, hsa-miR-15b-5p, hsa-miR-182-3p, hsa-miR-141-5p, hsa-miR-130b-5p, and hsa-miR-135b-3p) was identified to be able to distinguish human ovarian cancer tissues from normal tissues with 97% sensitivity and 92% specificity. Two miRNA clusters of miR183-96-183 (miR-96-5p, and miR-182, miR183) and miR200 (miR-141-5p, miR200a, b, c and miR429) are significantly up-regulated in ovarian cancer tissue samples compared to those of normal tissue samples, suggesting theses miRNAs may be involved in ovarian cancer development.

UNLABELLED: Hepatocellular carcinoma (HCC) is the major primary liver cancer. Glypican-3 (GPC3), one of the most abnormally expressed genes in HCC, participates in liver carcinogenesis. Based on data showing that GPC3 expression is posttranscriptionally altered in HCC cells compared to primary hepatocytes, we investigated the implication of microRNAs (miRNAs) in GPC3 overexpression and HCC. To identify GPC3-regulating miRNAs, we developed a dual-fluorescence FunREG (functional, integrated, and quantitative method to measure posttranscriptional regulations) system that allowed us to screen a library of 876 individual miRNAs. Expression of candidate miRNAs and that of GPC3 messenger RNA (mRNA) was measured in 21 nontumoral liver and 112 HCC samples. We then characterized the phenotypic consequences of modulating expression of one candidate miRNA in HuH7 cells and deciphered the molecular mechanism by which this miRNA controls the posttranscriptional regulation of GPC3. We identified five miRNAs targeting GPC3 3'-untranslated region (UTR) and regulating its expression about the 876 tested. Whereas miR-96 and its paralog miR-1271 repressed GPC3 expression, miR-129-1-3p, miR-1291, and miR-1303 had an inducible effect. We report that miR-1271 expression is down-regulated in HCC tumor samples and inversely correlates with GPC3 mRNA expression in a particular subgroup of HCC. We also report that miR-1271 inhibits the growth of HCC cells in a GPC3-dependent manner and induces cell death.
CONCLUSION: Using a functional screen, we found that miR-96, miR-129-1-3p, miR-1271, miR-1291, and miR-1303 differentially control GPC3 expression in HCC cells. In a subgroup of HCC, the up-regulation of GPC3 was associated with a concomitant down-regulation of its repressor miR-1271. Therefore, we propose that GPC3 overexpression and its associated oncogenic effects are linked to the down-regulation of miR-1271 in HCC.

MicroRNAs (miRNAs) are small noncoding RNAs that involved in various cancer-related cellular processes. Diverse studies on expression profiling of miRNAs have been performed and the data showed that some miRNAs are up-regulated or down-regulated in cancer. Until now, there are no data published on the miRNA expression in head and neck cancers from Malaysia. Hence, this study aimed to investigate potentially crucial miRNAs in head and neck cancer patients from Malaysian populations. A global miRNA profiling was performed on 12 samples of head and neck cancer tissue using microarray analysis followed by validation using real-time RT-PCR. Microarray analysis identified 10 miRNAs that could distinguish malignant head and neck cancer lesions from normal tissues; 7 miRNAs (hsa-miR-181a-2*, hsa-miR-29b-1*, hsa-miR-181a, hsa-miR-181b, hsa-miR-744, hsa-miR-1271 and hsa-miR-221*) were up-regulated while 3 miRNAs (hsa-miR-141, hsa-miR-95 and hsa-miR-101) were down-regulated. These miRNAs may contribute in a simple profiling strategy to identify individuals at higher risk of developing head and neck cancers, thus helping in the elucidation of the molecular mechanisms involved in head and neck cancer pathogenesis.