Growth arrest-specific 5 attenuates cisplatin-induced apoptosis in cervical cancer by regulating STAT3 signaling via miR-21

Cervical cancer is the most common cause of female cancer-related mortality worldwide. Decreased expression of long noncoding RNA growth arrest-specific 5 (GAS5) is found in human cervical cancer tissues and associated with poor prognosis. However, the studies on associations between GAS5 level and malignant phenotypes, as well as sensitivity to chemotherapeutic drug in cervical cancer cells are limited. In this study, overexpression of GAS5 in cervical cancer cells resulted in prohibited cell proliferation and colony formation, which were promoted by siGAS5. Enhanced GAS5 increased cell percentage in the G0/G1 phase and decreased cells percentage in the S phase, whereas reduced expression did not. The malignant behaviors of cervical cancer cells, manifested by cell migration and invasion, could be weakened by the GAS5 overexpression and enhanced by siGAS5. Furthermore, in cisplatin-induced cell, overexpression of GAS5 reduced cells viability and enhanced apoptosis, whereas in cells transfected with siGAS5, apoptosis eliminated. We have reported the upregulation of microRNA-21 (miR-21) and its oncogenetic roles in cervical cancer previously. In this study, we found the negative relationship between the GAS5 and miR-21. Moreover, the decrease of miR-21 associated proteins phosphorylated STAT3 and E2F3 was seen in GAS5 overexpressed cells, both of which could be increased by siGAS5. The GAS5 deficiency also reduced miR-21 target proteins TIMP3 and PDCD4 expressions. Taken together, the GAS5 expression level is inversely associated with malignancy, but positively associated with sensitivity to cisplatin-induced apoptosis, suggesting that GAS5 could be a biomarker of cisplatin-resistance in clinical therapy of human cervical cancer.     

MicroRNA-21 promotes the proliferation and inhibits apoptosis in Eca109 via activating ERK1/2/MAPK pathway

The aim of this study was to investigate how miR-21 promotes proliferation and inhibits apoptosis in esophageal squamous cell carcinoma (ESCC). MTT, wound healing assay and cell cycle showed that proliferation and migration of ESCC cell line Eca109 cells were increased in miR-21 mimics group, and decreased in anti-miR-21 Oligonucleotide (AMO) group after transfection into Eca109 cells with miR-21 mimics, AMO and scramble sequence, respectively. Cell apoptosis assay indicated that cell apoptosis can be obviously inhibited by overexpression of miR-21 and promoted by downregulation of miR-21. Meanwhile, western-blot results showed that p-ERK1/2 expression was elevated in miR-21 mimics group, whereas decreased in AMO group. Furthermore, the ERK1/2, a key component of MAPK signaling pathway, was knocked down, and overexpressed successfully using shRNA-ERK1/2 and overexpressing plasmids containing full length cDNA of ERK1/2, respectively. It was observed that shRNA-ERK1/2 can significantly decreased the level of miR-21 expression, while overexpression of ERK1/2 can up-regulate expression of miR-21. As further confirmation, Eca109 cells were treated with gradient concentration of U0126, a kind of MEK inhibitor, and expression of miR-21 was subsequently examined. It was found that U0126 can significantly decreased endogenous expression of miR-21. In parallel, U0126 decreased cell proliferation, migration and increased the apoptosis in Eca109 cells, with the expression of miR-21 being reduced significantly in U0126 group as compared with control groups. Our findings indicated that miR-21 promoted the proliferation, migration and inhibited apoptosis of Eca109 cells through activating ERK1/2/MAPK pathway, and that targeting miR-21 could be a promising therapeutic strategy in ESCC.     

Tumor-suppressive microRNA-10a inhibits cell proliferation and metastasis by targeting Tiam1 in esophageal squamous cell carcinoma

Aberrant microRNAs (miRNAs) expressions could contribute to the progression of numerous cancers, including esophageal squamous cell carcinoma, while miR-10a participates in multiple biological processes on cancers. However, the molecular mechanism of miR-10a in esophageal squamous cell carcinoma (ESCC) has not been investigated. Herein, miR-10a was significantly reduced in ESCC clinical tissues and ESCC cell lines (EC109 and TE-3). In addition, immunohistochemistry indicated that the expressions of α-SMA, Ki-67, and PCNA in tumor tissues were higher than that of controls. In vitro, overexpression of miR-10a dramatically suppressed cell proliferation and enhanced cell apoptosis, while the decrease of miR-10a expressed the opposite outcome. Specially, overexpression of miR-10a caused a G0/G1 peak accumulation. Moreover, miR-10a also negatively regulated ESCC cell migration and invasion. Furthermore, targetscan bioinformatics predictions and the dual-luciferase assay confirmed that Tiam1 was a direct target gene of miR-10a. The statistical analysis showed Tiam1 was negatively in correlation with miR-10a in ESCC patient samples. And silencing Tiam1 could lead to a decline on cell growth, invasion, and migration in ESCC cell lines, while it could enhance cell apoptosis and cause a G0/G1 peak accumulation. In vivo, it revealed that miR-10a notably decreased the tumor growth and metastasis in xenograft model and pulmonary metastasis model. And it showed a lower expressions of Tiam1 in the miR-10a mimics group by immunohistochemistry. Taken together the results, they indicated that miR-10a might function as a novel tumor suppressor in vitro and in vivo via targeting Tiam1, suggesting miR-10a to be a candidate biomarker for the ESCC therapy.     

Inhibiting UHRF1 expression enhances radiosensitivity in human esophageal squamous cell carcinoma

Radiotherapy is an effective treatment for some esophageal cancers, but the molecular mechanisms of radiosensitivity remain unknown. Ubiquitin-like with PHD and ring finger domains 1 (UHRF1) is a novel nuclear protein which is overexpressed in various cancers but not yet examined in esophageal squamous cell carcinoma (ESCC). The correlation between UHRF1 and the radioresistance in ESCC is still unclear. In the present study, the expression of UHRF1 was examined by immunohistochemistry in specimens of ESCC patients treated with radiotherapy. The results showed that UHRF1 was significantly overexpressed in ESCC specimens. Overexpression of UHRF1 correlated significantly with advanced T-stage, positive lymph node metastasis and poor differentiation. In addition, UHRF1 was associated with radiotherapy response, in which overexpression of UHRF1 was observed more frequently in the radioresistant group than in the effective group. At the molecular level, inhibition of UHRF1 by lentivirus-mediated shRNA targeting UHRF1 increased the radiosensitivity and apoptosis, while decreased radiation-induced G2/M phase arrest in TE-1 cells. Moreover, inhibition of UHRF1 resulted in higher residual γH2AX expression after irradiation, but not initial γH2AX. Further study showed that inhibition of UHRF1 down-regulated the endogenous expressions of DNA repair protein Ku70 and Ku80 in TE-1 cells, and significantly inhibited the increase of these proteins after irradiation. Above all, our data suggested that UHRF1 might play an important role in radioresistance of ESCC, and inhibition of UHRF1 can increase the radiosensitivity of TE-1 cells by altering cell cycle progression, enhancing apoptosis, and decreasing DNA damage repair capacity.     

LINC00473/miR-374a-5p regulates esophageal squamous cell carcinoma via targeting SPIN1 to weaken the effect of radiotherapy

Esophageal squamous cell carcinoma (ESCC) is the most prevalent type in esophageal cancers. Despite accumulating achievements in treatments of ESCC, patients still suffer from recurrence because of the treatment failures, one of the reasons for which is radioresistance. Therefore, it is a necessity to explore the molecular mechanism underlying ESCC radioresistance. Long intergenic noncoding RNA 473 (LINC00473) has been reported to be aberrantly expressed in several human malignancies. However, its biological function in radiosensitivity of ESCC remains to be fully understood. This study explored the role of LINC00473 in radiosensitivity of ESCC cells and whether LINC00473 acted as a competing endogenous RNA to realize its modulation on radioresistance. We found that LINC00473 was markedly upregulated in ESCC tissues and cell lines, and its expression was remarkably related to cellular response to irradiation. In addition, knockdown of LINC00473 could sensitize ESCC cells to radiation in vitro. As for the underlying mechanism, we uncovered that there was a mutual inhibition between LINC00473 and miR-374a-5p. Spindlin1 (SPIN1) was verified as a downstream target of miR-374a-5p, and LINC00473 upregulated SPIN1 expression through negatively modulating miR-374a-5p expression. Furthermore, we revealed that SPIN1 could aggravate the radioresistance of ESCC cells. Finally, overexpression of SPIN1 reversed the LINC00473 silencing-enhanced radiosensitivity in ESCC cells. To sum up, we demonstrated that LINC00473 facilitated radioresistance by regulating the miR-374a-5p/SPIN1 axis in ESCC.     

Long intergenic non-protein coding RNA 00858 participates in the occurrence and development of esophageal squamous cell carcinoma through the activation of the FTO-m6A-MYC axis by recruiting ZNF184

ObjectivesWe aimed at probing impact of LINC00858 on esophageal squamous cell carcinoma (ESCC) progression via ZNF184-FTO-m⁶A-MYC axis.MethodsExpression of related genes (LINC00858, ZNF184, FTO, and MYC) was detected in ESCC tissues or cells and their relationships were assessed. After expression alterations in ESCC cells, cell proliferation, invasion, migration, and apoptosis were detected. Tumor formation in nude mice was conducted.ResultsLINC00858, ZNF184, FTO, and MYC were overexpressed in ESCC tissues and cells. LINC00858 enhanced ZNF184 expression to upregulate FTO, which augmented MYC expression. LINC00858 knockdown diminished ESCC cell proliferative, migratory, and invasive properties while elevating apoptosis, which was negated by FTO overexpression. FTO knockdown exerted similar functions of LINC00858 knockdown on ESCC cell movements, which was annulled by MYC upregulation. Silencing LINC00858 repressed tumor growth and related gene expression in nude mice.ConclusionsLINC00858 modulated MYC m⁶A modification via FTO by recruiting ZNF184, thus facilitating ESCC progression.     

MiR-34a targets GAS1 to promote cell proliferation and inhibit apoptosis in papillary thyroid carcinoma via PI3K/Akt/Bad pathway

MicroRNAs (miRNAs) are fundamental regulators of cell proliferation, differentiation, and apoptosis, and are implicated in tumorigenesis of many cancers. MiR-34a is best known as a tumor suppressor through repression of growth factors and oncogenes. Growth arrest specific1 (GAS1) protein is a tumor suppressor that inhibits cancer cell proliferation and induces apoptosis through inhibition of RET receptor tyrosine kinase. Both miR-34a and GAS1 are frequently down-regulated in various tumors. However, it has been reported that while GAS1 is down-regulated in papillary thyroid carcinoma (PTC), miR-34a is up-regulated in this specific type of cancer, although their potential roles in PTC tumorigenesis have not been examined to date. A computational search revealed that miR-34a putatively binds to the 3′-UTR of GAS1 gene. In the present study, we confirmed previous findings that miR-34a is up-regulated and GAS1 down-regulated in PTC tissues. Further studies indicated that GAS1 is directly targeted by miR-34a. Overexpression of miR-34a promoted PTC cell proliferation and colony formation and inhibited apoptosis, whereas knockdown of miR-34a showed the opposite effects. Silencing of GAS1 had similar growth-promoting effects as overexpression of miR-34a. Furthermore, miR-34a overexpression led to activation of PI3K/Akt/Bad signaling pathway in PTC cells, and depletion of Akt reversed the pro-growth, anti-apoptotic effects of miR-34a. Taken together, our results demonstrate that miR-34a regulates GAS1 expression to promote proliferation and suppress apoptosis in PTC cells via PI3K/Akt/Bad pathway. MiR-34a functions as an oncogene in PTC.     

miR-204-5p regulates cell proliferation,invasion, and apoptosis by targeting IL-11 in esophageal squamous cell carcinoma

Esophageal cancer (EC) is the world's eighth most common malignant neoplasm and is ranked as the sixth leading cause of death related to cancer. Aberrant microRNA (miRNA) expression has been reported to be associated with esophageal squamous cell carcinoma. However, the molecular mechanism of miR-204-5p in esophageal squamous cell carcinoma (ESCC) is not clear. Therefore, the aim of this study was to investigate the potential role of miR-204-5p in ESCC. In the present study, we found that miR-204-5p could affect ESCC proliferation, invasion, apoptosis, and cell cycle in cell and mouse models. A dual-luciferase reporter assay showed that miR-204-5p expression was negatively correlated with interleukin-11 (IL-11) expression. IL-11 overexpression reversed the suppressive effects of miR-204-5p in the cell lines. These results indicated that miR-204-5p functions as a tumor suppressor by directly targeting IL-11 in ESCC.     

MiR-34a in age and tissue related radio-sensitivity and serum miR-34a as a novel indicator of radiation injury

MiR-34a, a direct target of p53, has shown to exert potent anti-proliferative effects. It has also been found that miR-34a can be induced by irradiation in vitro and in vivo. However, the relationship between miR-34a and radio-sensitivity, and its potential diagnostic significance in radiation biology, remain unclear. This study found that differing responses to ionizing radiation (IR) of young and adult mice were related to miR-34a. First, we found that miR-34a could be induced in many organs by radiation of both young and adult mice. However, the level of miR-34a induced by young mice was much higher when compared to adult mice. Next, we found that miR-34a played a critical role in radio-sensitivity variations of different tissues by enhancing cell apoptosis and decreasing cell viability. We also found that the induction of miR-34a by radiation was in a p53 dependent manner and that one possible downstream target of miR-34a that lead to different radio-sensitivity was the anti-apoptosis molecular Bcl-2. However, over-expression of miR-34a and knockdown of Bcl-2 could significantly enhance the radio-sensitivity of different cells while inhibition of miR-34a could protect cells from radiation injury. Finally, we concluded that miR-34a could be stable in serum after IR and serve as a novel indicator of radiation injury. Taken together, this data strongly suggests that miR-34a may be a novel indicator, mediator and target of radiation injury, radio-sensitivity and radioprotection.     

Long non-coding RNA GAS5 sensitizes renal cell carcinoma to sorafenib via miR-21/SOX5 pathway

Although the use of sorafenib appears to increase the survival rate of renal cell carcinoma (RCC) patients, there is also a proportion of patients who exhibit a poor primary response to sorafenib treatment. Therefore, it is critical to elucidate the mechanisms underlying sorafenib resistance and find representative biomarkers for sorafenib treatment in RCC patients. Herein, we identified that a long noncoding RNA GAS5 was downregulated in sorafenib nonresponsive RCCs. GAS5 overexpression conferred sorafenib sensitive to nonresponsive RCC cells, whereas knockdown of GAS5 promoted responsive RCC cells resistant to sorafenib treatment in vitro and in vivo. Mechanistically, GAS5 functioned as competing endogenous RNA to repress miR-21, which controlled its down-stream target SOX5. We proposed that GAS5 was responsible for sorafenib resistance in RCC cells and GAS5 exerted its function through the miR-21/ SOX5 axis. Our findings suggested that GAS5 downregulation may be a new marker of poor response to sorafenib and GAS5 could be a potential therapeutic target for sorafenib treatment in RCC.     

抑癌因子miR-10a抑制Tiam1表达对胃癌细胞凋亡和迁移的影响

目的:探讨miR-10a抑制Tiam1表达对胃癌细胞凋亡和侵袭的影响。方法:获取胃上皮组织细胞及胃癌组织细胞,利用q PCR及Western blot实验检测两种细胞中mi R-10a表达与Tiam1的m RNA及蛋白表达水平,同时检测胃癌细胞S746T及正常胃粘膜细胞RGM-1和NGEC中mi R-10a表达与Tiam1蛋白表达水平。通过将mi R-10a mimic和mi R-10a inhibitor转染HS746T细胞,利用流式细胞术检测HS746T的细胞周期和细胞凋亡,TranswellTM实验检测HS746T细胞的侵袭能力,qPCR及Western blot实验检测凋亡相关蛋白caspase3、caspase9和Bax以及周期相关蛋白P21表达水平;荧光素酶活性分析实验检测Tiam1是mi R-10a的作用靶点。已构建的Tiam1高表达的Tiam1-pcDNA3.1质粒和敲除Tiam1基因的PX458质粒分别转染HS746T细胞,通过流式细胞术及TranswellTM实验检测HS746T细胞的凋亡及侵袭能力。结果:与胃上皮组织细胞相比,早期胃癌临床组织细胞中mi R-10a表达降低,Tiam1的m RNA及蛋白表达升高;mi R-10a的表达与早期胃癌患者的肿瘤转移密切相关,与年龄、性别和肿瘤分期无关;与正常胃粘膜细胞RGM-1和NGEC相比,胃癌细胞HS746T中的mi R-10a表达降低,而Tiam1蛋白表达升高;mi R-10a可抑制HS746T细胞侵袭,促进细胞凋亡,使其停滞于G0/G1期;mi R-10a靶向作用于Tiam1基因的3'非翻译区(3'UTR),减少Tiam1的蛋白表达;Tiam1可抑制HS746T细胞凋亡,促进HS746T细胞侵袭。结论:mi R-10a靶向作用于Tiam1基因的3'UTR,抑制HS746T细胞的增殖及侵袭,促进HS746T细胞凋亡。