Long non-coding RNA PVT1 facilitates cell proliferation by epigenetically regulating FOXF1 in breast cancer

Background: plasmacytoma variant translocation 1 (PVT1) has been identified as an oncogenic long non-coding RNA (lncRNA) in multiple cancers including breast cancer. However, its molecular basis has not been exhaustively elucidated. Methods: RT-qPCR assay was used to detect PVT1 expression in tissues and cells. The effect of PVT1 and FOXF1 on breast cancer cell proliferation was assessed by MTT, colony formation and cell cycle assays. Cell apoptotic rate was measured by flow cytometry via double-staining of Annexin V-FITC and PI. The protein expression patterns of forkhead box f1 (FOXF1) and enhancer of zeste homolog 2 (EZH2) were detected using western blot assays. The subcellular location of PVT1 was analyzed using subcellular fractionation assays. The interaction between PVT1 and EZH2 were demonstrated by RNA-protein pull down and RIP assays. ChIP assay was used to explore whether PVT1 affected FOXF1 expression by recruiting EZH2. In vivo assays were performed to further investigate the roles of PVT1 in breast cancer tumorigenesis. Results: PVT1 expression was elevated in breast cancer tissues and cells. Moreover, higher PVT1 level was positively associated with aggressive pathological status and poor prognosis of breast cancer. PVT1 knockdown suppressed proliferation and induced apoptosis in breast cancer cells. PVT1 silenced FOXF1 expression by recruiting EZH2 to the promoter region of FOXF1, resulting in the increase of H3K27me3 level. EZH2 inhibitor EPZ005687 counteracted PVT1-mediated enrichment effect on H3K27me3 and EZH2 to FOXF1 promoter region. FOXF1 overexpression hampered proliferation and facilitated apoptosis in breast cancer cells. Furthermore, down-regulation of FOXF1 partly abrogated PVT1-knockdown-mediated anti-proliferation and pro-apoptosis effect in breast cancer cells. Finally, PVT1 deficiency suppressed tumor growth by promoting FOXF1 expression in vivo. Conclusion: PVT1 promoted cell proliferation and suppressed apoptosis by epigenetically silencing FOXF1 expression through EZH2 in breast cancer.

Plasmacytoma variant translocation 1 (PVT1) expression was elevated in breast cancer tissues and correlated to breast cancer progression and prognosis.     

Retracted Article: Long noncoding RNA DLEU1 promotes cell proliferation and migration of Wilms tumor through the miR-300/HOXC8 axis

Wilms tumor (nephroblastoma) is the most common primary renal tumor occurring in children. Long noncoding RNA (lncRNA) deleted in lymphocytic leukemia 1 (DLEU1) is an identified cancer-associated lncRNA that plays an important role in various cancers. However, the role of DLEU1 in Wilms tumor remains unclear. In the present study, we examined the expression and role of DLEU1 in Wilms tumor. We demonstrated that DLEU1 expression was upregulated in Wilms tumor tissues and cell lines. Knockdown of DLEU1 significantly inhibited the proliferation, migration and invasion of GHINK-1 cells. Furthermore, DLEU1 directly sponged miR-300 and regulated the expression level of miR-300 in GHINK-1 cells. Inhibition of miR-300 reversed the inhibitory effects of DLEU1 downregulation on cell proliferation, migration and invasion. Homeobox C8 (HOXC8) was found to be a target gene of miR-300 and mediated the role of miR-300 in GHINK-1 cells. In conclusion, these findings indicated that DLEU1 executed an oncogenic role in Wilms tumor via regulating the miR-300/HOXC8 axis, indicating that DLEU1 might be a therapeutic target for the treatment of Wilms tumor.

Wilms tumor (nephroblastoma) is the most common primary renal tumor occurring in children.     

MicroRNA-137 down-regulates KIT and inhibits small cell lung cancer cell proliferation

MiR-137 expression was examined in parental and drug-resistant cell lines, H446 and H446/CDDP, of small lung cancer (SCLC), and the results showed there was fewer miR-137 expressed in H446/CDDP cells followed by KIT expression emergence. In order to confirm physiological function of these abnormal expressions, H446 and H446/CDDP cells were transfected with miR-137 inhibitor and miR-137 mimics, respectively, after that, miR-137 and KIT expression in two cell lines and drug sensitivity of these cells were evaluated. Results indicated that sensitivity of H446 cells to cisplatin significantly decreased after transfected with miR-137 inhibitor, while miR-137 mimics transfection increased drug sensitivity of H446/CDDP cells and deregulated KIT expression. Our data provided combined evidence that miR-137 was closely related to MDR of SCLC, and interfering of miR-137 expression may attenuate drug resistant of H446/CDDP cells to cisplatin partially through KIT expression regulation. Besides, it has also been proved that KIT might be only one of the downstream molecules of miR-137 that related to SCLC MDR.     

MicroRNA-31 functions as an oncogenic microRNA in mouse and human lung cancer cells by repressing specific tumor suppressors

MicroRNAs (miRNAs) regulate gene expression. It has been suggested that obtaining miRNA expression profiles can improve classification, diagnostic, and prognostic information in oncology. Here, we sought to comprehensively identify the miRNAs that are overexpressed in lung cancer by conducting miRNA microarray expression profiling on normal lung versus adjacent lung cancers from transgenic mice. We found that miR-136, miR-376a, and miR-31 were each prominently overexpressed in murine lung cancers. Real-time RT-PCR and in situ hybridization (ISH) assays confirmed these miRNA expression profiles in paired normal-malignant lung tissues from mice and humans. Engineered knockdown of miR-31, but not other highlighted miRNAs, substantially repressed lung cancer cell growth and tumorigenicity in a dose-dependent manner. Using a bioinformatics approach, we identified miR-31 target mRNAs and independently confirmed them as direct targets in human and mouse lung cancer cell lines. These targets included the tumor-suppressive genes large tumor suppressor 2 (LATS2) and PP2A regulatory subunit B alpha isoform (PPP2R2A), and expression of each was augmented by miR-31 knockdown. Their engineered repression antagonized miR-31–mediated growth inhibition. Notably, miR-31 and these target mRNAs were inversely expressed in mouse and human lung cancers, underscoring their biologic relevance. The clinical relevance of miR-31 expression was further independently and comprehensively validated using an array containing normal and malignant human lung tissues. Together, these findings revealed that miR-31 acts as an oncogenic miRNA (oncomir) in lung cancer by targeting specific tumor suppressors for repression.     

Increased serum exosomal long non‐coding RNA SNHG15 expression predicts poor prognosis in non‐small cell lung cancer

BackgroundCirculating long non‐coding RNAs (lncRNAs) are emerging as promising biomarkers for non‐small cell lung cancer (NSCLC). This study aimed to detect serum exosomal lncRNA SNHG15 expression in NSCLC and evaluate its potential clinical value.MethodsA total of 238 serum samples were collected from 118 patients with NSCLC, 40 patients with benign pulmonary lesions and 80 healthy volunteers. The expression levels of serum exosomal lncRNA SNHG15 were measured by quantitative real‐time polymerase chain reaction (qRT‐PCR). Then, the relationship between serum exosomal lncRNA SNHG15 expression and clinical parameters was analyzed.ResultsThe serum exosomal lncRNA SNHG15 expression was markedly higher in NSCLC patients compared to patients with benign pulmonary lesions and normal controls. As expected, serum exosomal lncRNA SNHG15 was greatly decreased after surgery. High serum exosomal lncRNA SNHG15 expression was closely associated with poor differentiation (p=0.035), positive lymph node metastasis (p=0.009) and advanced TNM stage (p<0.001). Receiver operating characteristic (ROC) curve analysis demonstrated that serum exosomal lncRNA SNHG15 well differentiated all stage NSCLC, stage I/II NSCLC patients or stage III/IV NSCLC patients from controls, and the combination of serum exosomal lncRNA SNHG15 and CEA showed an elevated AUC for distinguishing NSCLC from healthy individuals. In univariate and multivariate analyses, serum exosomal lncRNA SNHG15 was confirmed as an independent prognostic predictor for overall survival.ConclusionIn conclusion, our findings suggest that serum exosomal lncRNA SNHG15 might be a potential biomarker for early diagnosis and prognosis prediction of NSCLC.     

结直肠癌组织中lncRNA FOXC2-AS1与EZH2的表达及临床意义

目的探讨结直肠癌(CRC)组织中长链非编码RNA(lncRNA)RNA FOXC2-AS1、Zeste基因增强子同源物2(EZH2)表达及临床意义。方法采用实时荧光定量PCR检测86例CRC癌组织和癌旁组织中lncRNA FOXC2-AS1、EZH2的表达。采用免疫组化法检测癌组织和癌旁组织中EZH2的蛋白表达。采用Pearson相关分析lncRNA FOXC2-AS1与EZH2表达的相关性。统计学分析癌组织中lncRNA FOXC2-AS1、EZH2的表达与临床病理特征之间的关系。Kaplan-Meier生存曲线分析不同lncRNA FOXC2-AS1、EZH2表达水平患者的5年总体生存率的差异。结果与癌旁组织比较,癌组织中lncRNA FOXC2-AS1及EZH2 mRNA表达水平升高(P<0.05),EZH2蛋白表达阳性率较高(P<0.05)。癌组织中lncRNA FOXC2-AS1与EZH2 mRNA表达水平呈正相关(r=0.623,P<0.05)。癌组织中lncRNA FOXC2-AS1及EZH2表达与肿瘤分期有关(P<0.05),与患者的性别、年龄、肿瘤大小、肿瘤位置、肿瘤分化程度及是否伴淋巴结转移无关(P>0.05)。Kaplan-Meier生存曲线分析结果显示lncRNA FOXC2-AS1及EZH2高表达的患者5年总体生存率低于lncRNA FOXC2-AS1及EZH2低表达患者(P<0.05)。结论CRC癌组织中lncRNA FOXC2-AS1及EZH2表达水平升高,lncRNA FOXC2-AS1及EZH2的高表达与肿瘤分期有关,二者有望成为新的评价肿瘤预后的分子标志物。     

Retracted Article: SNHG3 promotes proliferation and invasion by regulating the miR-101/ZEB1 axis in breast cancer

Background: Dysregulated lncRNA expression contributes to the pathogenesis of human tumors via the lncRNAs functioning as oncogenes or tumor suppressors. Small nucleolar RNA host gene 3 (SNHG3) was demonstrated to be upregulated in breast cancer cells. However, the detailed roles and molecular mechanism of SNHG3 in breast cancer are largely unknown. Methods: The expression of SNHG3, miR-101, and zinc finger E-box-binding protein 1 (ZEB1) in breast cancer tissues and cells was detected using qRT-PCR. The effects of SNHG3 on cell proliferation and invasion were evaluated using MTT, EdU, and cell invasion assays. The protein levels of Ki-67, proliferating cell nuclear antigen (PCNA), matrix metalloproteinase MMP-2, and MMP-9 were analyzed using western blot analysis. A luciferase reporter assay and RNA immunoprecipitation (RIP) were performed to explore the interaction between SNHG3, ZEB1 and miR-101. A subcellular fractionation assay was used to detect the subcellular location of SNHG3. Xenograft tumor experiments were conducted to verify the role and mechanism of SNHG3 in breast cancer in vivo. Results: SNHG3 expression was upregulated in breast cancer tissues and correlated with poor prognosis. SNHG3 knockdown suppressed breast cancer cell proliferation and invasion, which was further demonstrated by high levels of proliferation marker proteins Ki-67/PCNA and metastasis-related proteins MMP-2/MMP-9. Additionally, SNHG3 was located in the cytoplasm of breast cancer cells. SNHG3 functioned as a molecular sponge for miR-101 in breast cancer cells. miR-101 was downregulated in breast cancer tissues and negatively correlated with SNHG3 expression. Moreover, ZEB1, a target of miR-101, was positively regulated by SNHG3 in breast cancer cells. ZEB1 mRNA expression was upregulated in breast cancer tissues and positively correlated with SNHG3 expression. Mechanistically, SNHG3 knockdown suppressed cell proliferation and invasion by upregulation of miR-101 and downregulation of ZEB1 expression in breast cancer cells in vitro and in vivo. Conclusion: SNHG3 promoted proliferation and invasion by regulating the miR-101/ZEB1 axis in breast cancer.

In the present study, we investigated the expression and functional roles of SNHG3 in breast cancer cells, as well as the underlying mechanism of SNHG3 involved in the progression of breast cancer in vitro and in vivo.     

Knockdown of Forkhead box A1 suppresses the tumorigenesis and progression of human colon cancer cells through regulating the phosphatase and tensin homolog/Akt pathway

BackgroundThis study aimed to evaluate the role and the underlying mechanisms of Forkhead box A1 (encoded by FOXA1) in colon cancer.MethodsWe analyzed FOXA1 mRNA and protein expression in colon cancer tissues and cell lines. We also silenced FOXA1 expression in HCT116 and SW480 cells to evaluate the effects on cell proliferation, cell cycle, migration, and invasion by using MTT, colony formation, flow cytometry, and the Transwell assay, respectively.ResultsFOXA1 immunostaining was higher in colon cancer tissues than adjacent healthy tissues. FOXA1 mRNA and protein expression was significantly increased in human colon cancer cells compared with a normal colonic cell line. FOXA1 expression was also significantly higher in colorectal cancer tissues from TCGA data sets and was associated with worse prognosis in the R2 database. FOXA1 expression was negatively correlated with the extent of its methylation, and its knockdown reduced proliferation, migration, and invasion, and induced G2/M phase arrest in HCT116 and SW480 cells by suppressing the phosphatase and tensin homolog/Akt signaling pathway and inhibiting epithelial–mesenchymal transition.ConclusionFOXA1 may act as an oncogene in colon cancer tumorigenesis and development.     

Possible involvement of the Hedgehog and PDPK1–Akt pathways in the growth and migration of small-cell lung cancer

BackgroundSmall-cell lung cancer (SCLC) accounts for approximately 15% to 20% of all lung cancers, and it is the leading cause of tumor-related deaths globally. This study explored the molecular mechanisms underlying the development of SCLC.MethodsThe correlations of phosphoinositide-dependent kinase-1 (PDPK1), p-Akt, and Hedgehog expression with patient characteristics were analyzed using SCLC specimens, and their expression was measured in BEAS-2B cells (control) and the SCLC cell lines H82, H69, H446, H146, and H526. Transfection experiments were performed to inhibit or activate gene expression in cells. We then measured the proliferation and migration of H146 cells.ResultsPDPK1, p-Akt, and Hedgehog expression was significantly higher in SCLC tissues, and their expression was correlated with patient characteristics. p-Akt expression was significantly correlated with Hedgehog expression. In H146 cells, PDPK1 and p-Akt were significantly upregulated. Silencing of PDPK1 or Akt and inhibition of Hedgehog significantly inhibited the proliferation and migration of H146 cells. PDPK1 and Akt affected Hedgehog expression, but Hedgehog did not affect PDPK1 or p-Akt expression.ConclusionsThe interaction between the PDPK1–Akt pathway and the Hedgehog pathway influences the prognosis, growth, and migration of SCLC.     

LncRNA HOTAIR与BRCA-1在胃癌组织中的表达水平与顺铂化疗抵抗的影响

目的:研究lncRNA HOTAIR与BRCA-1在胃癌组织中的表达水平与顺铂化学药物治疗(以下简称化疗)抵抗的相关性。方法:选择2014年2月至2016年5月滨海县人民医院收治的胃癌根治术后并接受顺铂进行化疗的120例患者。采用实时定量PCR法检测所有患者胃癌组织、配对正常组织中lncRNA HOTAIR和BRCA-1的表达水平。比较患者胃癌组织与正常组织中lncRNA HOTAIR,BRCA-1表达水平,分析lncRNA HOTAIR与BRCA-1的表达与顺铂化疗效果的相关性。结果:在lncRNA组患者胃癌组织中lncRNA HOTAIR表达阳性者73例(60.8%),相对表达水平为7.63±0.14;在正常组织中lncRNA HOTAIR表达阳性者26例(21.7%),相对表达水平为2.32±0.06;lncRNA HOTAIR表达阳性者使用顺铂化疗2年的无复发率为8.33%(10例),阴性患者2年的无复发率为16.67%(20例)。在BRCA-1组患者胃癌组织中BRCA-1表达阳性者70例(58.3%),相对表达水平为15.39±4.28;在正常组织中BRCA-1表达阳性者4例(3.3%),相对表达水平为5.71±2.13;BRCA-1表达阳性者使用顺铂化疗2年的无复发率为5.00%(6例),阴性患者2年的无复发率为14.17%(17例)。结论:LncRNA HOTAIR及BRCA-1在胃癌组织中的表达量显著高于正常组织,与顺铂化疗抵抗具有一定的关联性,这两种标志物可作为胃癌患者术后化疗药物选择及预后判断的参考依据。     

Integrated Functional, Gene Expression and Genomic Analysis for the Identification of Cancer Targets

The majority of new drug approvals for cancer are based on existing therapeutic targets. One approach to the identification of novel targets is to perform high-throughput RNA interference (RNAi) cellular viability screens. We describe a novel approach combining RNAi screening in multiple cell lines with gene expression and genomic profiling to identify novel cancer targets. We performed parallel RNAi screens in multiple cancer cell lines to identify genes that are essential for viability in some cell lines but not others, suggesting that these genes constitute key drivers of cellular survival in specific cancer cells. This approach was verified by the identification of PIK3CA, silencing of which was selectively lethal to the MCF7 cell line, which harbours an activating oncogenic PIK3CA mutation. We combined our functional RNAi approach with gene expression and genomic analysis, allowing the identification of several novel kinases, including WEE1, that are essential for viability only in cell lines that have an elevated level of expression of this kinase. Furthermore, we identified a subset of breast tumours that highly express WEE1 suggesting that WEE1 could be a novel therapeutic target in breast cancer. In conclusion, this strategy represents a novel and effective strategy for the identification of functionally important therapeutic targets in cancer.     

Targeted Expression of miR-34a Using the T-VISA System Suppresses Breast Cancer Cell Growth and Invasion

Recurrence and metastasis result in a poor prognosis for breast cancer patients. Recent studies have demonstrated that microRNAs (miRNAs) play vital roles in the development and metastasis of breast cancer. In this study, we investigated the therapeutic potential of miR-34a in breast cancer. We found that miR-34a is downregulated in breast cancer cell lines and tissues, compared with normal cell lines and the adjacent nontumor tissues, respectively. To explore the therapeutic potential of miR-34a, we designed a targeted miR-34a expression plasmid (T-VISA-miR-34a) using the T-VISA system, and evaluated its antitumor effects, efficacy, mechanism of action, and systemic toxicity. T-VISA-miR-34a induced robust, persistent expression of miR-34a, and dramatically suppressed breast cancer cell growth, migration, and invasion in vitro by downregulating the protein expression levels of the miR-34a target genes E2F3, CD44, and SIRT1. In an orthotopic mouse model of breast cancer, intravenous injection of T-VISA-miR-34a:liposomal complex nanoparticles significantly inhibited tumor growth, prolonged survival, and did not induce systemic toxicity. In conclusion, T-VISA-miR-34a lead to robust, specific overexpression of miR-34a in breast cancer cells and induced potent antitumor effects in vitro and in vivo. T-VISA-miR-34a may provide a potentially useful, specific, and safe-targeted therapeutic approach for breast cancer.     

SNHG5 promotes proliferation and induces apoptosis in melanoma by sponging miR-155

Background: Melanoma is the most common malignancy of skin cancer. Small nucleolar RNA host gene 5 (SNHG5), a long non-coding RNA (lncRNA), has been demonstrated to be abnormally expressed in multiple malignances. However, the roles and molecular mechanisms of SNHG5 in melanoma progression have not been well identified. Methods: RT-qPCR assays were used to detect the expression patterns of SNHG5 and microRNA-155 (miR-155). Cell proliferation was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays. Cell apoptosis rate was measured by flow cytometry via double-staining of fluorescein isothiocyanate (FITC)-labeled annexin V (Annexin V-FITC) and propidium iodide (PI). The interaction between SNHG5 and miR-155 was validated using bioinformatics analysis, subcellular fraction assay, luciferase assay and RNA immunoprecipitation (RIP) assay. A mouse model of melanoma was established to further verify the effect of SNHG5 on tumor growth in vivo. Results: SNHG5 expression was upregulated in melanoma tumor tissues and cell lines. Moreover, higher SNHG5 expression was associated with advanced pathogenic status and poor prognosis. Functional analysis showed that SNHG5 knockdown suppressed proliferation and facilitated apoptosis in melanoma cells. Mechanical exploration revealed that SNHG5 acted as a molecular sponge of miR-155 in melanoma cells. Restoration experiments delineated that miR-155 down-regulation partly abrogated SNHG5-knockdown-mediated anti-proliferation and pro-apoptosis effect in melanoma cells. In vivo assays further demonstrated that SNHG5 depletion hindered tumor growth through up-regulating miR-155 expression. Conclusion: SNHG5 promoted the development of melanoma by sponging miR-155 in vitro and in vivo, implying the important implication of lncRNAs in melanoma progression and providing a potential therapeutic target for melanoma.

Melanoma is the most common malignancy of skin cancer. Small nucleolar RNA host gene 5 (SNHG5), a long non-coding RNA (lncRNA), has been demonstrated to be upregulated in tumor tissues and cells of melanoma.     

长链非编码RNA LINC00922促进胰腺导管腺癌的增殖、迁移和侵袭

目的 检测长链非编码RNA linc00922在胰腺癌组织及胰腺癌细胞系中表达,并探究linc00922对胰腺癌细胞系增殖、迁移和侵袭的影响。方法 利用illumina HiSeq X Ten高通量测序仪针对2015年-2016年间4对胰腺导管腺癌组织与癌旁组织进行高通量测序,建立lncRNA及mRNA表达谱,并挑选其中胰腺癌组织中显著高表达的lncRNA linc00922做为进一步研究对象。应用实时定量反转录聚合酶链反应(RT-qPCR)技术验证linc00922在10例胰腺癌及癌旁组织中表达情况。通过CCK-8增殖实验,划痕实验及Transwell实验探究linc00922对胰腺癌细胞系BXPC-3增殖、迁移及侵袭的调控作用。采用配对样本t检验,或独立样本t检验进行统计学分析。结果 前期通过高通量测序分析,发现胰腺癌组织中470个差异表达lncRNA,4373个差异表达mRNA,其中linc00922在胰腺癌组织中显著高表达。在10例胰腺癌组织及癌旁组织样本中,利用RT-qPCR进一步验证了linc00922在胰腺癌组织中显著高表达(p<0.05)。CCK-8增殖实验提示敲低linc00922表达的BXPC-3胰腺癌细胞增殖活力显著低于阴性对照组(p<0.05)。划痕实验提示敲低linc00922表达的BXPC-3胰腺癌细胞的迁移能力显著低于较阴性对照组(p<0.05)。Transwell侵袭实验提示敲低linc00922表达的BXPC-3胰腺癌细胞的侵袭能力显著低于较阴性对照组(p<0.05)。结论 linc00922在胰腺癌中显著高表达,并具有促进胰腺癌细胞增殖、迁移和侵袭的能力。     

长链非编码RNA KCNQ1OT1靶向调控miR-218-5p对结肠癌细胞生物学行为的影响

目的:探讨长链非编码RNA KCNQ1重叠转录物1(lncRNA KCNQ1OT1)调控micro RNA-218-5p(miR-218-5p)对结直肠癌细胞恶性生物学行为的影响及其可能机制。方法:收集2019年1月至4月在宜昌市第一人民医院行根治性结肠癌切除术的30例肿瘤组织和相应的癌旁正常组织。采用实时荧光定量PCR法(qRT-PCR)检测lncRNA KCNQ1OT1,miR-218-5p在结肠癌组织、癌旁正常组织、5种结直肠癌细胞系(HCT-116,SW480,SW620,DLD-1,HT29)及正常结肠上皮细胞系CCD841中的表达水平;干预结肠癌细胞系HCT-116和SW480中lncRNA KCNQ1OT1和miR-218-5p的表达,采用CCK-8法检测结肠癌细胞的增殖,Transwell法检测结肠癌细胞的迁移和侵袭;采用流式细胞术检测细胞周期分布及细胞凋亡率;用Starbase数据库预测lncRNA KCNQ1OT1的靶向miRNA,并用qRT-PCR、双荧光素酶报告基因法验证lncRNA KCNQ1OT1与miR-218-5p的靶向关系。结果:与癌旁正常组织和正常结肠上皮细胞系相比,结直肠癌组织和结直肠癌细胞系中lncRNA KCNQ1OT1的表达水平显著上调,miR-218-5p的表达显著下调(P<0.05);过表达lncRNA KCNQ1OT1促进SW480细胞的增殖、迁移和侵袭,且减少处于G0/G1期的细胞比率,抑制细胞凋亡;在结直肠癌组织中lncRNA KCNQ1OT1的表达水平与miR-218-5p的表达水平呈负相关(r^2=0.437,P<0.001);双荧光素酶报告基因法分析证实lncRNA KCNQ1OT1能特异性结合miR-218-5p,并能降低其表达;过表达miR-218-5p抑制HCT-116细胞的增殖、迁移和侵袭,增加处于G0/G1期的细胞比率,促进细胞凋亡,且miR-218-5p的表达可以抑制由lncRNA KCNQ1OT1过表达引起的细胞增殖、迁移和侵袭能力的增加及凋亡的减少。结论:LncRNA KCNQ1OT1通过靶向调控miR-218-5p表达影响结直肠癌细胞的增殖、迁移和侵袭,促进结直肠癌的发展。     

CD47-blocking immunotherapies stimulate macrophage-mediated destruction of small-cell lung cancer

Small-cell lung cancer (SCLC) is a highly aggressive subtype of lung cancer with limited treatment options. CD47 is a cell-surface molecule that promotes immune evasion by engaging signal-regulatory protein alpha (SIRPα), which serves as an inhibitory receptor on macrophages. Here, we found that CD47 is highly expressed on the surface of human SCLC cells; therefore, we investigated CD47-blocking immunotherapies as a potential approach for SCLC treatment. Disruption of the interaction of CD47 with SIRPα using anti-CD47 antibodies induced macrophage-mediated phagocytosis of human SCLC patient cells in culture. In a murine model, administration of CD47-blocking antibodies or targeted inactivation of the Cd47 gene markedly inhibited SCLC tumor growth. Furthermore, using comprehensive antibody arrays, we identified several possible therapeutic targets on the surface of SCLC cells. Antibodies to these targets, including CD56/neural cell adhesion molecule (NCAM), promoted phagocytosis in human SCLC cell lines that was enhanced when combined with CD47-blocking therapies. In light of recent clinical trials for CD47-blocking therapies in cancer treatment, these findings identify disruption of the CD47/SIRPα axis as a potential immunotherapeutic strategy for SCLC. This approach could enable personalized immunotherapeutic regimens in patients with SCLC and other cancers.