<Emphasis Type="Italic">microRNA-145</Emphasis> modulates epithelial-mesenchymal transition and suppresses proliferation,migration and invasion by targeting <Emphasis Type="Italic">SIP1</Emphasis> in human cervical cancer cells

Purpose

Previously, it has been reported that microRNA-145 (miR-145) is lowly expressed in human cervical cancers and that its putative tumour suppressive role may be attributed to epithelial-mesenchymal transition (EMT) regulation. Here, we aimed to assess whether miR-145 may affect EMT-associated markers/genes and suppress cervical cancer growth and motility, and to provide a mechanistic basis for these phenomena.

Methods

The identification of the SMAD-interacting protein 1 (SIP1) mRNA as putative miR-145 target was investigated using a 3’ untranslated region (3’UTR) luciferase assay and Western blotting, respectively. The functional effects of exogenous miR-145 expression, miR-145 suppression or siRNA-mediated SIP1 expression down-regulation in cervical cancer-derived C33A and SiHa cells were analysed using Western blotting, BrdU incorporation (proliferation), transwell migration and invasion assays. In addition, the expression levels of miR-145 and SIP1 were determined in primary human cervical cancer and non-cancer tissue samples using qRT-PCR.

Results

We found that miR-145 binds to the wild-type 3’UTR of SIP1, but not to its mutant counterpart, and that, through this binding, miR-145 can effectively down-regulate SIP1 expression. In addition, we found that exogenous miR-145 expression or siRNA-mediated down-regulation of SIP1 expression attenuates the proliferation, migration and invasion of C33A and SiHa cells and alters the expression of the EMT-associated markers CDH1, VIM and SNAI1, whereas inhibition of endogenous miR-145 expression elicited the opposite effects. The expression of miR-145 in cervical cancer tissue samples was found to be low, while that of SIP1 was found to be high compared to non-cancerous cervical tissues. An inverse expression correlation between the two was substantiated through the anlaysis of data deposited in the TCGA database.

Conclusion

Our data indicate that low miR-145 expression levels in conjunction with elevated SIP1 expression levels may contribute to cervical cancer development. MiR-145-mediated regulation of SIP1 provides a novel mechanistic basis for its tumour suppressive mode of action in human cervical cancer cells.

     

RETRACTED ARTICLE: Downregulation of miR-148b as biomarker for early detection of hepatocellular carcinoma and may serve as a prognostic marker

MicroRNAs (miRNAs) have a large number of various target genes in different cancer types, which may result in many biological functions. Thus, identifying the molecular mechanisms of miRNAs may effect on the complexity of cancer progression via regulation of gene. In the current study, we utilized real-time PCR to quantify the diction of miR-148b in trail hepatocellular carcinoma (HCC) specimen and normal tissues. Furthermore, we evaluated the relationship of miR-148b and clinicopathological features with survival of HCC patients. Therefore, we evaluated the level of miR-148b expression in 101 HCC patients and also in 40 normal control cases. The result suggested lower expression in tumor tissues than normal control tissues (0.96?±?0.14; 1.84?±?0.20, P?<?0.05). Our findings suggest that the declined expression of miR-148b can considerably be linked to tumor node metastasis (TNM) stage (stages III and IV; P?=?0.021) and vein invasion (P?=?0.029). Nevertheless, miR-148b expression was not related to sex (P?=?0.674), age (P?=?0. 523), size of tumor (P?=?0.507), liver cirrhosis, and histologic grade (P?=?0.734). Survival analysis showed that low expression was remarkably related to overall survival (P?=?0.012). Furthermore, multivariate survival test suggested that decline of miR-148b diction was linked to poor survival in HCC patients. Our results suggested that miR-148b is decreased in HCC. Therefore, we concluded that miR-148b may play its role in the prognosis of HCC.     

Expression analysis of three miRNAs,miR-26a,miR-29b and miR-519d,in relation to <Emphasis Type="Italic">MMP</Emphasis>-<Emphasis Type="Italic">2</Emphasis> expression level in non-small cell lung cancer patients: a pilot study

Lung cancer is the most common cause of death in men and second only to breast cancer in women. MicroRNAs (miRNAs) are involved in tumorigenesis and function as oncogenes or tumor suppressor genes. Among other genes, miRNAs regulate matrix metalloproteinases (MMPs), the proteolytic enzymes playing a significant role in the degradation of extracellular matrix, enhancing tumor invasion and metastasis. The aim of the study was to evaluate the expression levels of selected miRNAs: miR-26a, miR-29b and miR-519d, and their target gene, matrix metalloproteinase-2 (MMP-2) in patients with non-small cell lung cancer (NSCLC). The results were correlated with tumor staging, NSCLC histopathological subtypes and patients’ demographical features to assess the possible diagnostic/prognostic value of the studied miRNAs and MMP-2. Total RNA was isolated from 38 NSCLC tissue samples, and the expression analysis was performed using TaqMan^® probes in qPCR assay. The results indicated underexpression of selected miRNAs and overexpression of MMP-2. The decrease in miRNA-29b expression was statistically significant and differentiated NSCLC histopathological subtypes. Additionally, statistically significant negative correlation was found between MMP-2 expression and its regulatory miR-26a. There are very few studies reporting miRNA-MMPs analysis on mRNA level in lung cancer, and no similar reports are available from Polish population. The results of our pilot study indicated the diagnostic potential of miR-29b and MMP-2, an inverse association between miR-26a and MMP-2, and proved the role of MMP-2 and the studied miRNAs in lung carcinogenesis. Further studies are needed to verify their potential usefulness for the treatment of lung cancer.     

Long noncoding RNA <Emphasis Type="Italic">MALAT1</Emphasis> regulates autophagy associated chemoresistance via miR-23b-3p sequestration in gastric cancer

Background

Chemoresistance has long been recognized as a major obstacle in cancer therapy. Clarifying the underlying mechanism of chemoresistance would result in novel strategies to improve patient’s response to chemotherapeutics.

Methods

lncRNA expression levels in gastric cancer (GC) cells was detected by quantitative real-time PCR (qPCR). MALAT1 shRNAs and overexpression vector were transfected into GC cells to down-regulate or up-regulate MALAT1 expression. In vitro and in vivo assays were performed to investigate the functional role of MALAT1 in autophagy associated chemoresistance.

Results

We showed that chemoresistant GC cells had higher levels of MALAT1 and increased autophagy compared with parental cells. Silencing of MALAT1 inhibited chemo-induced autophagy, whereas MALAT1 promoted autophagy in gastric cancer cells. Knockdown of MALAT1 sensitized GC cells to chemotherapeutics. MALAT1 acts as a competing endogenous RNA for miR-23b-3p and attenuates the inhibitory effect of miR-23b-3p on ATG12, leading to chemo-induced autophagy and chemoresistance in GC cells.

Conclusions

Taken together, our study revealed a novel mechanism of lncRNA-regulated autophagy-related chemoresistance in GC, casting new lights on the understanding of chemoresistance.

     

Gastrokine 1 inhibits gastric cancer cell migration and invasion by downregulating RhoA expression

Background

We investigated whether GKN1, a gastric tumor suppressor, contributes to the progression of gastric cancer by regulating RhoA expression.

Methods

We analyzed the expression of GKN1, RhoA, miR-185, and miR-34a in 35 gastric cancer tissues, and compared their expression with T category and TNM stage. Cell migration and invasion, as well as the expression of epithelial-to-mesenchymal transition (EMT)-related proteins, were assessed in GKN1- and RhoA small interfering RNA (siRhoA)-transfected and recombinant-GKN1-treated AGS and MKN1 gastric cancer cells.

Results

Expression of RhoA protein and messenger RNA (mRNA) was increased in 15 (42.9 %) and 17 (48.6 %) of 35 gastric cancer tissues respectively, and was associated with higher T category and TNM stage. GKN1 expression was significantly decreased in 27 gastric cancers (77.1 %) with a higher T category, and was inversely correlated with RhoA mRNA expression. In AGS and MKN1 cells, GKN1 expression increased miR-185 and miR-34a expression and reduced RhoA mRNA and protein expression. A positive relationship between GKN1 and miR-34a and miR-185 expression and an inverse relationship between miR-34a and RhoA expression were observed in gastric cancer tissues. Cell migration and invasiveness were markedly decreased in GKN1- and siRhoA-transfected cells. GKN1 expression and silencing of RhoA decreased the expression of the proteins Snail, Slug, and vimentin. Furthermore, miR-185 and miR-34a silencing in MKN1 cells transfected with GKN1 stimulated cell migration and invasion, and increased the expression of EMT-related proteins.

Conclusion

Our data suggest that GKN1 may inhibit gastric cancer cell migration and invasion by downregulating RhoA expression in a miR-185- and miR-34a-dependent manner.

     

MicroRNAs miR-7 and miR-340 predict response to neoadjuvant chemotherapy in breast cancer

Purpose

miRNAs have been linked to chemosensitivity of breast cancer cells in vitro. In patients, however, there is no clinically validated method for predicting chemotherapy response. The aim of this study was to assess whether (I) a specific pattern of miRNA expression in pretherapeutic biopsies can predict response to neoadjuvant chemotherapy, and (II) differential miRNA expression in residual tumor after completion of chemotherapy allows further prognostic stratification of non-responding patients.

Methods

Sixty-four patients with newly diagnosed large (≥3 cm) or locally advanced primary breast cancers who underwent neoadjuvant anthracycline/taxane-based chemotherapy were included. Relative expression of 10 miRNAs likely to be associated with chemotherapy response (miR-7,-21,-29a,-29b,-34a,-125b,-155,-200c,-340,-451) was determined by quantitative RT-PCR from pretherapeutic biopsies (n = 64) and residual invasive tumor after chemotherapy (n = 42). Pathologic complete response (pCR) defined by absence of invasive tumor served as reference standard. In addition, miRNA expression was compared with disease-free and overall survival.

Results

Nine (14%) of 64 patients achieved pCR. High expression of miR-7 and low expression of miR-340 in pretherapeutic biopsies predicted pCR with a negative predictive value of 96 and 97%, respectively (specificity 54 and 57%). The combined profile of miR-7^high/miR-340^low demonstrated improved specificity of 86% while maintaining a high negative predictive value (96%) to identify non-responders. Pretherapeutic expression of miR-200c and miR-155 showed prognostic information, and low expression was associated with increased overall survival (115 vs. 90 months, p ≤ 0.03). After chemotherapy, the overall survival of patients with residual invasive tumor was better for those demonstrating low miR-7 or high miR-125b (p = 0.01).

Conclusions

Intratumoral expression of miR-7 and miR-340 prior to neoadjuvant chemotherapy could be used to predict pCR and a profile of miR-7^low or miR-340^high identified patients unlikely to achieve pCR who might benefit from alternative treatment options including earlier surgery. Our study identifies miRNAs as promising predictive biomarkers, which could aid in optimization of breast cancer management and treatment stratification.

     

RETRACTED ARTICLE: MicroRNA-216b is Down-Regulated in Human Gastric Adenocarcinoma and Inhibits Proliferation and Cell Cycle Progression by Targeting Oncogene HDAC8

Purpose

Accumulating evidence indicates that micro (mi)RNAs play a critical role in carcinogenesis and cancer progression; however, their role in the tumorigenesis of gastric adenocarcinoma remains unclear so the present study investigated this in gastric cancer (GC) tissues and cell lines.

Methods

Human GC specimens (n?=?57) and patient-paired non-cancerous specimens were obtained from patients at the First Affiliated Hospital, Henan University of Science and Technology. The AGS and GC9811 gastric cancer cell lines were also used. Expression levels of miR-216b and HDAC8 were examined by quantitative real-time PCR and the expression of HDAC8 was also examined by Western blotting and immunohistochemistry assay. The cell cycle progression was determined by FACS. MiR-216b inhibitor, mimics, and siRNA-HDAC8 transfections were performed to study the loss and gain of function.

Results

We reported a significantly decreased expression of miR-216b in GC clinical specimens compared with paired non-cancerous tissues. We also observed a significant down-regulation of miR-216b expression in GC cell lines AGS and GC9811 (p?<?0.0001). The introduction of miR-216b suppressed GC cell proliferation and cell cycle progression by targeting HDAC8, an oncogene shown to promote malignant tumor development with a potential miR-216b binding site in its 3′ untranslated region. HDAC8 expression was shown to be significantly increased in AGS and GC9811 cell lines (p?<?0.0001) and GC tissues compared with controls. Moreover, HDAC8 inhibition suppressed cell cycle progression compared with control groups (22 %?±?1.6 % vs 34 %?±?2.1), indicating that HDAC8 may function as an oncogene in the development of GC. Furthermore, HDAC8 expression was negatively correlated (p?<?0.0001), while miR-216b expression was positively correlated with the clinical outcome of GC patients (p?<?0.0001).

Discussion

Our data suggest that miR-216b functions as a tumor suppressor in human GC by, at least partially, targeting HDAC8.

Open image in new window

     

MicroRNA-585 acts as a tumor suppressor in non-small-cell lung cancer by targeting <Emphasis Type="Italic">hSMG</Emphasis>-<Emphasis Type="Italic">1</Emphasis>

Purpose

To investigate the role of miR-585 in the development and progression of non-small-cell lung cancer (NSCLC).

Methods

The expression levels of miR-585 in NSCLC cell lines and clinical samples were measured by quantitative PCR. NSCLC cells, A549 and H1299, were stably transfected with lentiviral vectors of miR-585 mimics or negative control. The effects of miR-585 on cell proliferation were detected both in vitro and in vivo. Cell migration and invasion were evaluated using wound healing assay and Transwell assay. Furthermore, luciferase reporter assay was used to identify the direct regulation of hSMG-1 by miR-585.

Results

Our results showed that miR-585 was downregulated in NSCLC cell lines and tumor tissues. Ectopic expression of miR-585 inhibited the ability of cell proliferation, migration, and invasion in vitro. In addition, miR-585 also decreased the growth rate of xenografted tumor in nude mice. Mechanically, miR-585 directly targeted the 3′-untranslated region (UTR) of hSMG-1 gene, which likely resulted in a dysfunction of mRNA surveillance and nonsense-mediated mRNA decay.

Conclusion

Taken together, miR-585 probably has an inhibitory effect on tumor growth and is a prognostic biomarker of NSCLC.

     

miR-375 is upregulated in acquired paclitaxel resistance in cervical cancer

Background:

Chemo-resistance is one of the key causal factors in cancer death and emerging evidences suggest that microRNAs (miRNAs) have critical roles in the regulation of chemo-sensitivity in cancers. Cervical cancer is one of the most common malignancies in women and insensitive to chemotherapy clinically.

Methods:

The differentially expressed miRNAs in cervical squamous cell carcinoma tissues were screened by using a microarray platform (μParaflo Sanger miRBase release 13.0). The expression of miR-375 was determined by stem-loop RT–PCR using 23 clinical cervical cancer samples and 2 cervical cancer cell lines. We exogenously upregulated miR-375 expression in SiHa and Caski cells using a pre-miRNA lentiviral vector transfection and observed its impact on paclitaxel sensitivity using MTS. The cells that stably overexpressed miR-375 were subcutaneously injected into mice to determine tumour growth and chemo-sensitivity in vivo.

Results:

Twenty-one differentially expressed miRNAs were found by miRNA microarray between pro- and post-paclitaxel cervical cancer tissues. Of those, miR-375 showed consistent high expression levels across paclitaxel-treated cervical cells and tissues. Paclitaxel induced upregulated miR-375 expression in a clear dose-dependent manner. Forced overexpression of miR-375 in cervical cancer cells decreased paclitaxel sensitivity in vitro and in vivo.

Conclusion:

Collectively, our results suggest that miR-375 might be a therapeutic target in paclitaxel-resistant cervical cancer.     

RETRACTED ARTICLE: Downregulation of microRNA-217 and microRNA-646 acts as potential predictor biomarkers in progression,metastasis, and unfavorable prognosis of human osteosarcoma

Despite the progress in therapeutic targets, it remains dissatisfactory for most osteosarcoma patients with metastasis or recurrence osteosarcoma. Therefore, it is required to determine the involved mechanisms of osteosarcoma. The aim of this study was to investigate the expression level of MiR-217 and miR-646 and also their association with clinicopathological features in patients with osteosarcoma. Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues, and then quantitative real-time PCR was applied to evaluate the expression level of microRNAs. Our result suggested that miR-217 expression was remarkably deceased in osteosarcoma bone tissue when compared with noncancerous bone tissues (mean?±?SD 5.32?±?1.231, 2.01?±?0.78; P?=?0.024) and miR-646 expression decreased in osteosarcoma bone tissue in comparison with normal tissues (mean?±?SD 4.56?±?1.45, 1.76?±?1.24; P?=?0.041). Our findings indicated that decreased expression of MiR-217 and miR-646 was strongly correlated with high tumor, node, and metastasis (TNM) stage (P?=?0.015, P?=?0.002) and large cancer diameter (P?=?0.041, P?=?0.053). Kaplan-Meier survival and log-rank analysis indicated that shorter overall survival was strongly linked to decreased expression of miR-217 and miR-646 (log-rank test P?=?0.034, P?=?0.026). In terms of miR-217, multivariate Cox proportional hazards model analysis has showed that reduction of miR-217 expression (P?=?0.001), TNM stage (P?=?0.046), and lymph node metastasis (P?=?0.006) were independently linked to a short-time survival of patients. In terms of miR-646, low expression of miR-646 (P?=?0.021), TNM stage (P?=?0.052), and tumor size (P?=?0.043) were independently associated with poor survival of patients as prognostic factors. Our findings suggested that downregulation of MiR-217 and miR-646 was associated with progression of osteosarcoma. MiR-217 and miR-646 may play a key role in suppression of tumor in osteosarcoma and would be applied as a novel therapeutic agent.     

MicroRNA-143 replenishment re-sensitizes colorectal cancer cells harboring mutant,but not wild-type,KRAS to paclitaxel treatment

Colorectal cancer (CRC) global incidence is one of the highest among cancers. The KRAS gene has been shown as a robust biomarker for poor prognosis and drug resistance. MicroRNA-143 (miR-143) and let-7 are families of tumor suppressor microRNAs that are often downregulated in CRC, especially with coexistent KRAS mutations. In order to evaluate if miR-143 and/or let-7b replenishment would re-sensitize CRC cells to paclitaxel treatment, we investigated in effect of miR-143 and let-7b replenishments on sensitivity to paclitaxel treatment in KRAS mutant LoVo and wild-type SW48 CRC cell lines. Our results showed that miR-143, but not let-7b, increased sensitization of KRAS mutant tumor cells to paclitaxel. Furthermore, transfection of miR-143, but not let-7b, mimic negatively regulated the expression of mutant but not wild-type KRAS. Combination of miR-143 mimic and paclitaxel induced the onset of apoptosis, and reverted in vitro metastatic properties (migration and invasion) in KRAS mutant tumor cells. MiR-143 thus can be used as a chemosensitizer for the treatment of KRAS mutant tumors and warrants further investigations in in vitro and pre-clinical in vivo models.     

Association of HLA-G 3′ UTR polymorphism and expression with the progression of cervical lesions in human papillomavirus 18 infections

Background

Human leukocyte antigen (HLA)-G is an immune checkpoint molecule, which expression in cervical cancer cells enables them to escape immunosurveillance. To date, limited information has been published on the association of HLA-G genetic background in malignant cells with levels of HLA-G expression and the clinical outcome of patients.

Methods

We investigated the influence of the HLA-G 14?bp In/Del (rs66554220) and?+?3142C/G (rs1063320) polymorphisms in 130 cases of HPV16 infection, 130 cases of HPV18 infection and 185 age-matched, unrelated, HPV-negative, and cytologically normal Chinese Han women. Case-matched cervical biopsy tissues were evaluated by immunohistochemistry.

Results

Our findings show that the frequency of alleles, 14?bp In (38.5% vs 29.2%, OR?=?1.52, P?<?0.05) and?+?3142G (72.7% vs 57.0%, OR?=?2.01, P?<?0.05), were significantly increased in the HPV18-infected group compared with the control group. The HLA-G polymorphisms (alleles 14?bp In and?+?3142G) are also associated with the progression of HPV18-related cervical lesions. Moreover, HLA-G expression increased from CIN1 to CIN2/3 lesions and was highest in patients with adenocarcinoma; however, a significant association between these characteristics and the HLA-G polymorphisms was not observed.

Conclusion

Our results support that the HLA-G 14?bp In and?+?3142G alleles are risk factors for HPV18 infections and influence the progression of HPV18-related cervical lesions. This suggests that HLA-G-driven immune mechanisms play an important role in cervical carcinogenesis.

     

RETRACTED ARTICLE: Downregulation of miR-185 and upregulation of miR-218 expression may be potential diagnostic and prognostic biomarkers of human chondrosarcoma

Increasing evidence has confirmed that dysregulation of microRNAs (miRNAs) can contribute to the progression and metastasis of human tumors. Chondrosarcoma is the most common primary malignant bone tumor in adults and has no effective systemic treatment, and patients with this disease have poor survival. Thus, it is important to find new diagnostic markers and improve treatment options. In the current study, we are interested to examine the role of miR-185 and miR-218 expression in patients with chondrosarcoma using real-time PCR. Moreover, the association of the two miRNAs with clinicopathological features and prognosis was evaluated. Survival and Cox proportional hazards analyses were performed to find the association of miR-185 expression and miR-218 levels with prognosis in the patients. Our results indicated that the miR-185 expression was significantly downexpressed in clinical chondrosarcoma bone tissues compared with adjacent normal tissues (P?=?0.001). MiR-218 expression level was increased in clinical chondrosarcoma bone tissue than those adjacent normal tissues (P?=?0.001). Decreased expression of miR-185 showed remarkable correlation with advanced tumor stage (P?=?0.019), tumor grade (P?<?0.001), and distant metastasis (P?=?0.001). Moreover, high expression of miR-218 was strongly correlated with advanced tumor stage (P?=?0.014), tumor grade (P?<?0.001), and distant metastasis (P?=?0.002). Kaplan–Meier survival analysis revealed that the low miR-185 expression group and the high miR-218 expression group had remarkably shorter overall survival (log-rank test P?=?0.007, P?=?0.004). The multivariate Cox proportional hazards model indicated that decreased expression of miR-185 and increased expression of miR-218 (P?=?0.017, P?=?0.012), advanced tumor stage (P?=?0.006, P?=?0.012), tumor grade (P?=?0.032, P?=?0.016), and distant metastasis (P?=?0.004, P?=?0.015) were independently related to overall survival in patients with chondrosarcoma. In conclusion, downregulation of miR-185 and upregulation of miR-218 can be associated with progression of chondrosarcoma and also both of them may act as tumor suppressor genes in chondrosarcoma.     

MicroRNA-301a promotes migration and invasion by targeting TGFBR2 in human colorectal cancer

Background

MicroRNAs (miRNAs) have been reported to play crucial roles in regulating a variety of genes pivotal for tumor metastasis. MicroRNA-301a (miR-301a) is overexpressed and displays oncogenic activity in many cancers. However, little is known about the potential roles of miR-301a in colorectal cancer (CRC).

Methods

Taqman probe stem-loop real-time PCR was used to quantitatively measure the expression level of miR-301a in 48 cases of CRC tissues and the matched adjacent non-tumor mucosa as well as in CRC cell lines. miR-301a mimics and inhibitors were used to up-regulate and down-regulate miR-301a in CRC cells, respectively; lentivirus was used to construct miR-301a stably up- and down-regulated CRC cell lines. Metastasis ability was evaluated by transwell and wound healing assays while invasion was measured by transwell coated with matrix gel in vitro; in vivo metastasis was performed on nude mice model. The target of miR-301a was predicted by TargetScan software and validated by qRT-PCR, immunohistochemistry, western blot and luciferase reporter gene assay.

Results

The expression of miR-301a was significantly higher in lymph node metastasis positive CRC samples compared with negative ones. Downregulation of miR-301a significantly inhibited the migration and invasion both in vitro and in vivo while forced up-regulation of miR-301a promoted migration and invasion. TGFBR2 was identified to be the downstream target of miR-301a. Knockdown of TGFBR2 in cells treated by miR-301a inhibitor elevated the previously abrogated migration and invasion.

Conclusions

Our data indicated that miR-301a correlated with the metastatic and invasive ability in human colorectal cancers and miR-301a exerted its role as oncogene by targeting TGFBR2.

     

Decreased expression of MicroRNA-200 family in human breast cancer is associated with lymph node metastasis

Objectives

MicroRNA-200 family (miR-200f) has been consistently reported to be deregulated and modulate the metastatic process in multiple cancers. In the present study, we detected the expression of miR-200f in breast cancer (BC) tissue and explored its relationships with clinicopathological characteristics, especially with lymph node metastasis.

Methods

Expression levels of miR-200a, miR-200b, miR-200c, miR-141, and miR-429 in 99 pairs of BC tissues and adjacent normal tissues were measured by real-time quantitative PCR. The correlation between miR-200f level and multiple clinicopathological factors was then examined by Mann–Whitney test, ANOVA, and operating characteristic (ROC) analysis.

Results

All members of the miR-200f were down-regulated in BC tissue compared with that in normal adjacent tissue; miR-200a, miR-200b, and miR-200c were highly decreased (p < 0.05), while the differences of miR-141 and miR-429 between patients and the control group were not statistically significant. Furthermore, all five members were found to be distinctly decreased with the incidence of lymph node metastasis (p < 0.05); When the patients were divided into three groups according to the number of lymph node metastasis (0; 1–3; ≥4), a gradual decrease of miR-200f expression was observed with the increasing number of lymph node metastasis; ROC revealed that miR-200b can differentiate patients with lymph node metastasis from those without lymph node metastasis.

Conclusion

These observations imply that the down-regulation of miR-200f in human BC is associated with an invasive phenotype, and miR-200b may be useful to estimate the likelihood of the presence of pathologically positive lymph nodes.

     

Silencing of miR-193a-5p increases the chemosensitivity of prostate cancer cells to docetaxel

Background

Docetaxel-based chemotherapy failure in advanced prostate carcinoma has partly been attributed to the resistance of prostate cancer (PC) cells to docetaxel-induced apoptosis. Hence, there is an urgent need to identify mechanisms of docetaxel chemoresistance and to develop new combination therapies.

Methods

miR-193a-5p level was evaluated by qPCR in prostate tissues and cell lines, and its expression in the tissues was also examined by in situ hybridization. PC cell line (PC3 cell) was transfected with miR-193a-5p mimic or its inhibitor, and then cell apoptosis and the expression of its downstream genes Bach2 and HO-1 were detected by TUNEL staining and Western blotting. Luciferase reporter assay was used to detect the effect of miR-193a-5p and Bach2 on HO-1 expression. Xenograft animal model was used to test the effect of miR-193a-5p and docetaxel on PC3 xenograft growth.

Results

miR-193a-5p was upregulated in PC tissues and PC cell lines, with significant suppression of PC3 cell apoptosis induced by oxidative stress. Mechanistically, miR-193a-5p suppressed the expression of Bach2, a repressor of the HO-1 gene, by directly targeting the Bach2 mRNA 3′-UTR. Docetaxel treatment modestly decreased Bach2 expression and increased HO-1 level in PC3 cells, whereas a modest increase of HO-1 facilitated docetaxel-induced apoptosis. Notably, docetaxel-induced miR-193a-5p upregulation, which in turn inhibits Bach2 expression and thus relieves Bach2 repression of HO-1 expression, partly counteracted docetaxel-induced apoptosis, as evidenced by the increased Bcl-2 and decreased Bax expression. Accordingly, silencing of miR-193a-5p enhanced sensitization of PC3 cells to docetaxel-induced apoptosis. Finally, depletion of miR-193a-5p significantly reduced PC xenograft growth in vivo.

Conclusions

Silencing of miR-193a-5p or blockade of the miR-193a-5p-Bach2-HO-1 pathway may be a novel therapeutic approach for castration-resistant PC.