Tim-3 Expression in Cervical Cancer Promotes Tumor Metastasis

BackgroundT cell immunoglobulin mucin-3 (Tim-3) has been identified as a negative regulator of anti-tumor immunity. Recent studies highlight the important role of Tim-3 in the CD8⁺ T cell exhaustion that takes place in both human and animal cancer models. However, the nature of Tim-3 expression in the tumor cell and the mechanism by which it inhibits anti-tumor immunity are unclear. This present study aims to determine Tim-3 is expressed in cervical cancer cells and to evaluate the role of Tim-3 in cervical cancer progression.MethodologyA total of 85 cervical tissue specimens including 43 human cervical cancer, 22 cervical intraepithelial neoplasia (CIN) and 20 chronic cervicitis were involved. Tim-3 expression in tumor cells was detected and was found to correlate with clinicopathological parameters. Meanwhile, expression of Tim-3 was assessed by RT-PCR, Western Blot and confocal microscopy in cervical cancer cell lines, HeLa and SiHa. The migration and invasion potential of Hela cells was evaluated after inhibiting Tim-3 expression by ADV-antisense Tim-3.ConclusionsWe found that Tim-3 was expressed at a higher level in the clinical cervical cancer cells compared to the CIN and chronic cervicitis controls. We supported this finding by confirming the presence of Tim-3 mRNA and protein in the cervical cell lines. Tim-3 expression in tumor cells correlated with clinicopathological parameters. Patients with high expression of Tim-3 had a significant metastatic potential, advanced cancer grades and shorter overall survival than those with lower expression. Multivariate analysis showed that Tim-3 expression was an independent factor for predicting the prognosis of cervical cancer. Significantly, down-regulating the expression of Tim-3 protein inhibited migration and invasion of Hela cells. Our study suggests that the expression of Tim-3 in tumor cells may be an independent prognostic factor for patients with cervical cancer. Moreover, Tim-3 expression may promote metastatic potential in cervical cancers.     

Semaphorin 4D Promotes Skeletal Metastasis in Breast Cancer

Bone density is controlled by interactions between osteoclasts, which resorb bone, and osteoblasts, which deposit it. The semaphorins and their receptors, the plexins, originally shown to function in the immune system and to provide chemotactic cues for axon guidance, are now known to play a role in this process as well. Emerging data have identified Semaphorin 4D (Sema4D) as a product of osteoclasts acting through its receptor Plexin-B1 on osteoblasts to inhibit their function, tipping the balance of bone homeostasis in favor of resorption. Breast cancers and other epithelial malignancies overexpress Sema4D, so we theorized that tumor cells could be exploiting this pathway to establish lytic skeletal metastases. Here, we use measurements of osteoblast and osteoclast differentiation and function in vitro and a mouse model of skeletal metastasis to demonstrate that both soluble Sema4D and protein produced by the breast cancer cell line MDA-MB-231 inhibits differentiation of MC3T3 cells, an osteoblast cell line, and their ability to form mineralized tissues, while Sema4D-mediated induction of IL-8 and LIX/CXCL5, the murine homologue of IL-8, increases osteoclast numbers and activity. We also observe a decrease in the number of bone metastases in mice injected with MDA-MB-231 cells when Sema4D is silenced by RNA interference. These results are significant because treatments directed at suppression of skeletal metastases in bone-homing malignancies usually work by arresting bone remodeling, potentially leading to skeletal fragility, a significant problem in patient management. Targeting Sema4D in these cancers would not affect bone remodeling and therefore could elicit an improved therapeutic result without the debilitating side effects.     

膀胱癌组织中CXCR4 和CXCR7 的表达及临床意义

目的:探讨膀胱癌组织中趋化因子受体4(CXCR4)和趋化因子受体7(CXCR7)的表达及临床意义。方法:收集2012年1月至2014年1月我院收集的膀胱癌组织标本96例,肿瘤旁正常组织标本42例,采用免疫组化方法检测组织标本中CXCR4和CXCR7的表达情况。结果:96例癌组织中检出CXCR4阳性59例,阳性率为61.46%,检出CXCR7阳性表达71例,阳性率为73.96%;42例癌旁组织中检出CXCR4阳性11例,阳性率26.19%,检出CXCR7阳性8例,阳性率为19.05%,癌组织与癌旁组织中CXCR4和CXCR7的表达具有统计学差异(均P0.05);相关性分析显示在膀胱癌组织中,CXCR4和CXCR7的表达呈正相关性(r=0.497,P=0.001);CXCR4和CXCR7在浸润性高(T2-T3)的膀胱癌和分化程度低(G2-G3)的膀胱癌表达强度较高,且差异具有统计学意义(均P0.05)。结论:CXCR4和CXCR7协同参与了膀胱癌的发生发展,并且与肿瘤的分化程度和浸润程度密切相关,有望成为诊断和治疗的重要靶点,在临床应用上具有重要意义。     

CPNE8 Promotes Gastric Cancer Metastasis by Modulating Focal Adhesion Pathway and Tumor Microenvironment

Little is known about the oncogenic role or biological function of copine Ⅷ (CPNE8) in gastric cancer (GC). Based on TCGA database, we screened for CPNE8 and analyzed the expression of CPNE8 in GC. The correlations between CPNE8 and clinical features were analyzed using TCGA and GEO databases. The prognostic value of CPNE8 was assessed using Cox analysis and Kaplan-Meier curves. The results showed that increased expression of CPNE8 was positively correlated with metastasis and can be considered an independent prognostic risk factor for poor survival. We found that CPNE8 can promote cell proliferation, migration, and invasiveness in GC using in vitro and in vivo experiments. Our study demonstrated that CPNE8 promotes tumor progression via regulation of focal adhesion, and these effects can be rescued by focal adhesion kinase (FAK) inhibitor GSK2256098 or knockdown of FAK. In addition, CPNE8 was correlated significantly with the infiltration of cancer-associated fibroblasts and immune cells, as demonstrated by various algorithms, and high CPNE8 expression predicted poor efficacy of immune checkpoint therapy. Our findings suggest that CPNE8 modulates focal adhesion and tumor microenvironment to promote GC progression and invasiveness and could serve as a novel prognostic biomarker in GC.     

E-cadherin和KLF 4表达对胃癌侵袭转移的作用

观察E-cadherin,Krüppel-like factor 4(KLF4)蛋白在胃癌和正常胃黏膜组织中的表达,分析其与胃癌浸润、转移的关系.应用免疫组织化学SP法检测84例手术切除的胃癌标本及对应正常胃黏膜组织中E-cadherin,KLF4蛋白的表达.各指标之间相关因素的差异性比较采用χ2检验,E-cadherin,KLF4相关性研究采用Spearman相关分析.结果显示,与正常胃组织相比,E-cadherin、KLF4蛋白在胃癌组织中均呈低表达或者缺失(分别42.9%vs.95.24%,8.3%vs 81%,P<0.05).E-cadherin、KLF4蛋白的阳性表达率与组织分级(P<0.05)、肿瘤浸润深度(P<0.05)、淋巴转移(P<0.05)明确相关.Spearman相关分析显示KLF4蛋白与E-cadherin蛋白的表达呈正相关(P<0.05).因此,E-cadherin,KLF4蛋白水平低表达可能与胃癌浸润和转移有关,而联合检测更能有效判断胃癌这一生物学行为.     

N-myc Downstream Regulated Gene 1 (NDRG1) Promotes Metastasis of Human Scirrhous Gastric Cancer Cells through Epithelial Mesenchymal Transition

Our recent study demonstrated that higher expression of N-myc downregulated gene 1 (NDRG1) is closely correlated with poor prognosis in gastric cancer patients. In this study, we asked whether NDRG1 has pivotal roles in malignant progression including metastasis of gastric cancer cells. By gene expression microarray analysis expression of NDRG1 showed the higher increase among a total of 3691 up-regulated genes in a highly metastatic gastric cancer cell line (58As1) than their parental low metastatic counterpart (HSC-58). The highly metastatic cell lines showed decreased expression of E-cadherin, together with enhanced expression of vimentin and Snail. This decreased expression of E-cadherin was restored by Snail knockdown in highly metastatic cell lines. We next established stable NDRG1 knockdown cell lines (As1/Sic50 and As1/Sic54) from the highly metastatic cell line, and both of these cell lines showed enhanced expression of E-cadherin and decreased expression of vimentin and Snail. And also, E-cadherin promoter-driven luciferase activity was found to be increased by NDRG1 knockdown in the highly metastatic cell line. NDRG1 knockdown in gastric cancer cell showed suppressed invasion of cancer cells into surround tissues, suppressed metastasis to the peritoneum and decreased ascites accumulation in mice with significantly improved survival rates. This is the first study to demonstrate that NDRG1 plays its pivotal role in the malignant progression of gastric cancer through epithelial mesenchymal transition.     

Identification and Characterization of CXCR4-Positive Gastric Cancer Stem Cells

Diffuse-type solid tumors are often composed of a high proportion of rarely proliferating (i.e., dormant) cancer cells, strongly indicating the involvement of cancer stem cells (CSCs) Although diffuse-type gastric cancer (GC) patients have a poor prognosis due to high-frequent development of peritoneal dissemination (PD), it is limited knowledge that the PD-associated CSCs and efficacy of CSC-targeting therapy in diffuse-type GC. In this study, we established highly metastatic GC cell lines by in vivo selection designed for the enrichment of PD-associated GC cells. By microarray analysis, we found C-X-C chemokine receptor type 4 (CXCR4) can be a novel marker for highly metastatic CSCs, since CXCR4-positive cells can grow anchorage-independently, initiate tumors in mice, be resistant to cytotoxic drug, and produce differentiated daughter cells. In clinical samples, these CXCR4-positive cells were found from not only late metastasis stage (accumulated ascites) but also earlier stage (peritoneal washings). Moreover, treatment with transforming growth factor-β enhanced the anti-cancer effect of docetaxel via induction of cell differentiation/asymmetric cell division of the CXCR4-positive gastric CSCs even in a dormant state. Therefore, differentiation inducers hold promise for obtaining the maximum therapeutic outcome from currently available anti-cancer drugs through re-cycling of CSCs.     

miRNA影响胃癌转移的机制

转移是恶性肿瘤基本的生物学特征,胃癌转移是导致胃癌患者死亡的主要原因. 诸多研究表明,微小RNA在胃癌转移过程中起着重要作用. 本文总结了有关抑制和促进胃癌转移微小RNA的研究新进展,并从影响信号传导途径、调控癌基因和抑癌基因表达、作用于细胞因子等方面分析了其主要作用机制.     

MicroRNA 135a Suppresses Lymph Node Metastasis through Down-Regulation of ROCK1 in Early Gastric Cancer

MicroRNAs (miRNAs) play a critical role in gastric cancer progression and metastasis. This study investigated the role of miRNA-135a in early gastric cancer (EGC) including lymph node (LN) metastasis. We examined the correlation between miRNA-135a expression and clinical outcomes in 59 patients who underwent surgery for EGC. Using gastric cancer cell lines, we performed functional and target gene analyses. miRNA-135a expression was down-regulated in 33.9% of patients. These patients showed a significantly more advanced stage (TNM stage≥IB, 35.0% vs. 12.8%, p = 0.045) and higher rate of LN metastasis (30.0% vs. 5.1%, p = 0.014) than those with up-regulation of miRNA-135a expression. In a multivariate analysis, down-regulation of miRNA-135a was an independent risk factor for LN metastasis (adjusted odds ratio, 8.04; 95% confidence interval, 1.08–59.81; p = 0.042). Functional analyses using gastric cancer cell lines showed that miRNA-135a suppressed cell viability, epithelial-mesenchymal transition, cell invasion, and migration. ROCK1 was a target of miRNA-135a and its expression was inversely correlated to that of miRNA-135a. ROCK1 expression was significantly increased in EGC patients with LN metastasis than in those without LN metastasis. Our results confirm the tumor-suppressive role of miRNA-135a, and demonstrate its role in LN metastasis in EGC. miRNA-135a and its target gene ROCK1 may be novel therapeutic and prognostic targets for EGC.     

TrkB Promotes Breast Cancer Metastasis via Suppression of Runx3 and Keap1 Expression

In metastatic breast cancer, the acquisition of malignant traits has been associated with the increased rate of cell growth and division, mobility, resistance to chemotherapy, and invasiveness. While screening for the key regulators of cancer metastasis, we observed that neurotrophin receptor TrkB is frequently overexpressed in breast cancer patients and breast cancer cell lines. Additionally, we demonstrate that TrkB expression and clinical breast tumor pathological phenotypes show significant correlation. Moreover, TrkB expression was significantly upregulated in basal-like, claudin-low, and metaplastic breast cancers from a published microarray database and in patients with triple-negative breast cancer, which is associated with a higher risk of invasive recurrence. Interestingly, we identified a new TrkB-regulated functional network that is important for the tumorigenicity and metastasis of breast cancer. We demonstrated that TrkB plays a key role in regulation of the tumor suppressors Runx3 and Keap1. A markedly increased expression of Runx3 and Keap1 was observed upon knockdown of TrkB, treatment with a TrkB inhibitor, and in TrkB kinase dead mutants. Additionally, the inhibition of PI3K/AKT activation significantly induced Runx3 and Keap1 expression. Furthermore, we showed that TrkB enhances metastatic potential and induces proliferation. These observations suggest that TrkB plays a key role in tumorigenicity and metastasis of breast cancer cells through suppression of Runx3 or Keap1 and that it is a promising target for future intervention strategies for preventing tumor metastasis and cancer chemoprevention.     

SDF-1/CXCR4及VEGF-C 在喉癌淋巴结转移中的作用机制

目的:探讨SDF-1/CXCR4及VEGF-C在喉癌淋巴结转移中的作用机制。方法:随机选取2012年8月至2015年8月我院收治的90例喉癌患者,将这些患者作为研究组,另选取20例具有相应正常粘膜组织的患者为对照组,运用免疫组化SP法对CXCR4及VEGF-C及SDF-1进行检测,分析SDF-1/CXCR4及VEGF-C在喉癌淋巴结组织中的表达及其与临床病理特征的关系。结果:喉癌组织中CXCR4、VEGF-C、SDF-1的阳性表达率均显著高于正常组织(P0.05);Ⅲ+Ⅳ患者CXCR4、VEGF-C、SDF-1的阳性表达率均显著高于Ⅰ+Ⅱ患者(P0.05);低分化患者CXCR4、VEGF-C的阳性表达率均显著高于高中分化患者(P0.05),但SDF-1阳性表达率之间比较,差异均不具有统计学意义(P0.05);淋巴结转移患者CXCR4、VEGF-C、SDF-1的阳性表达率均显著高于未发生淋巴结转移的患者,差异具有统计学意义(P0.05);不同年龄、病变部位患者CXCR4、VEGF-C、SDF-1阳性表达率之间比较,差异均不具有统计学意义(P0.05);喉癌组织中CXCR4及VEGF-C阳性表达均呈显著的正相关关系(P0.05);阴性表达也均呈显著的正相关关系(P0.05)。结论:SDF-1/CXCR4及VEGF-C在喉癌淋巴结转移中高表达,可能共同促进喉癌淋巴结转移。     

miRNA-20a促进卵巢癌细胞OVCAR3的转移

目的检测miRNA．20a对卵巢癌细胞系OVCAR3转移能力的影响。方法通过实时定量RT-PCR验证反义寡核苷酸与小干扰RNA封闭与过表达的效果,然后利用MTF、软琼脂集落形成和transwell侵袭实验检测封闭和过表达miRNA．20a对OVCAR3细胞增殖及转移能力的影响。结果封闭内源性miRNA-20a后,细胞活性基本不受影响,但集落形成能力和细胞的转移能力明显降低。过表达miRNA-20a后,细胞活性基本不受影响,但集落形成能力和细胞的转移能力明显升高。结论miRNA-20a可能参与了卵巢癌细胞OVCAR3的转移。     

Long Noncoding RNA MRUL Promotes ABCB1 Expression in Multidrug-Resistant Gastric Cancer Cell Sublines

Multidrug resistance (MDR) is the most common cause of chemotherapy failure in gastric cancer (GC) treatment; however, the underlying molecular mechanisms remain elusive. Long noncoding RNAs (lncRNAs) can be involved in carcinogenesis, but the effects of lncRNAs on MDR are poorly understood. We show here that the lncRNA MRUL (MDR-related and upregulated lncRNA), located 400 kb downstream of ABCB1 (ATP-binding cassette, subfamily B, member 1), was significantly upregulated in two multidrug-resistant GC cell sublines, SGC7901/ADR and SGC7901/VCR. Furthermore, the relative expression levels of MRUL in GC tissues were negatively correlated with in vitro growth inhibition rates of GC specimens treated with chemotherapeutic drugs and indicated a poor prognosis for GC patients. MRUL knockdown in SGC7901/ADR and SGC7901/VCR cells led to increased rates of apoptosis, increased accumulation, and reduced doxorubicin (Adriamycin [ADR]) release in the presence of ADR or vincristine. Moreover, MRUL depletion reduced ABCB1 mRNA levels in a dose- and time-dependent manner. Heterologous luciferase reporter assays demonstrated that MRUL might positively affect ABCB1 expression in an orientation- and position-independent manner. Our findings indicate that MRUL promotes ABCB1 expression and is a potential target to reverse the MDR phenotype of GC MDR cell sublines.     

CXCR4/Akt信号通路对食管癌细胞侵袭和肿瘤转移的调控作用

多项研究发现CXCR4在各种类型的癌症中高表达,然而尚不清楚CXCR4在食管癌细胞生长和转移中的作用。本研究检测了CXCR4在食管癌组织和细胞系(TE-1)中的表达,并通过转染CXCR4-短发夹RNA(CXCR4-sh RNA)慢病毒来敲低TE-1细胞中CXCR4的表达。应用PI3K/AKT抑制剂LY294002(50μmol/L)处理TE-1细胞12 h来考察AKT信号在食管癌细胞生长和转移中的作用;应用蛋白质印迹分析检测AKT和Rho家族蛋白(RhoA,Rac-1和Cdc42)的表达;应用CCK-8实验检测细胞增殖;Transwell实验检测细胞侵袭;对雄性BALB/c-nu/nu裸鼠皮下注射转染CXCR4-shRNA的TE-1细胞建立肿瘤异种移植模型。研究显示,CXCR4在食管癌组织中的表达水平明显高于癌旁组织,并且与TNM分期和淋巴结转移有关。CXCR4在人食管鳞状细胞癌细胞系(TE-1)中的表达水平明显高于人正常食管上皮细胞系(human normal esophageal epithelial cell line,HEEC)。敲低CXCR4能抑制食管鳞状细胞癌细胞的增殖和侵袭能力,并抑制肿瘤异种移植裸鼠的肿瘤形成。敲低CXCR4抑制了AKT的磷酸化及RhoA、Rac-1和Cdc42的表达。此外,PI3K/AKT抑制剂LY294002处理显著降低了TE-1细胞中AKT的磷酸化,并降低了RhoA、Rac-1和Cdc42的表达。本研究表明,CXCR4在食管癌患者中上调,与不良预后相关。下调CXCR4的表达可在体内和体外抑制食管癌肿瘤的生长和转移。下调CXCR4可通过抑制AKT信号的激活来抑制Rho家族粘附/侵袭相关蛋白的表达,从而抑制肿瘤转移。