膜联蛋白Ⅱ在胃癌组织中的表达及其在胃癌转移中的作用

目的：探讨膜联蛋白Ⅱ（AnnexinⅡ）在胃癌组织中的表达及其在胃癌转移中的作用。方法采用免疫组织化学法检测AnnexinⅡ在51例胃癌组织和24例癌旁组织中的表达,并统计AnnexinⅡ阳性表达与胃癌患者临床特征的关系。用AnnexinⅡ特异性siRNA在胃癌HGC-27细胞抑制AnnexinⅡ的表达,应用黏附实验、侵袭实验检测抑制AnnexinⅡ表达后对胃癌细胞的黏附、侵袭能力的影响。结果 AnnexinⅡ蛋白在胃癌组织中阳性率为82.4%,在癌旁组织中阳性率为37.5%,两组比较差异有统计学意义（P﹤0.01）;并且AnnexinⅡ阳性表达与患者的性别与年龄无关（P﹥0.05）,而与肿瘤大小、组织分化程度、临床分期、淋巴结转移临床特征有关,差异具有统计学意义（P﹤0.05）。在胃癌HGC-27细胞转染AnnexinⅡsiRNA后,细胞中AnnexinⅡ的蛋白和mRNA水平均下降,差异有统计学意义（P﹤0.05）。并且抑制AnnexinⅡ表达后,胃癌HGC-27细胞的黏附、侵袭能力下降,差异有统计学意义（P﹤0.05）。结论 AnnexinⅡ在胃癌组织中高表达,AnnexinⅡ蛋白表达与肿瘤大小、组织分化程度、临床分期、淋巴结转移临床特征有关,并且AnnexinⅡ高表达可促进胃癌转移。因此,AnnexinⅡ可以作为抑制胃癌转移的潜在靶点,开发靶向AnnexinⅡ的药物可能成为治疗胃癌转移的新方法。     

miR-145 inhibits tumor growth and metastasis by targeting metadherin in high-grade serous ovarian carcinoma

High-grade serous ovarian carcinoma (HGSOC), the most common and aggressive subtype of epithelial ovarian cancer, is characterized by TP53 mutations and genetic instability. Using miRNA profiling analysis, we found that miR-145, a p53 regulated miRNA, was frequently down-regulated in HGSOC. miR-145 down-regulation was further validated in a large cohort of HGSOCs by qPCR. Overexpression of miR-145 in ovarian cancer cells significantly suppressed proliferation, migration and invasion in vitro and inhibited tumor growth and metastasis in vivo. Metadherin (MTDH) was subsequently identified as a direct target of miR-145, and was found to be significantly up-regulated in HGSOC. Furthermore, overexpression of MTDH rescued the inhibitory effects of miR-145 in ovarian cancer cells. Finally, we found that high level of MTDH expression correlated with poor prognosis of HGSOC. Therefore, lack of suppression of MTDH by miR-145 when p53 is dysfunctional leads to increased tumor growth and metastasis of HGSOC. Our study established a new link between p53, miR-145 and MTDH in the regulation of tumor growth and metastasis in HGSOC.     

SIK2 promotes ovarian cancer cell motility and metastasis by phosphorylating MYLK

Salt‐inducible kinase 2 (SIK2; also known as serine/threonine‐protein kinase SIK2) is overexpressed in several cancers and has been implicated in cancer progression. However, the mechanisms by which SIK2 regulates cancer cell motility, migration and metastasis in ovarian cancer have not been fully discovered. Here, we identify that SIK2 promotes ovarian cancer cell motility, migration and metastasis in vitro and in vivo. Mechanistically, SIK2 regulated cancer cell motility and migration by myosin light chain kinase, smooth muscle (MYLK)‐meditated phosphorylation of myosin light chain 2 (MYL2). SIK2 directly phosphorylated MYLK at Ser343 and activated its downstream effector MYL2, promoting ovarian cancer cell motility and metastasis. In addition, we found that adipocytes induced SIK2 phosphorylation at Ser358 and MYLK phosphorylation at Ser343, enhancing ovarian cancer cell motility. Moreover, SIK2 protein expression was positively correlated with the expression of MYLK‐pS343 in ovarian cancer cell lines and tissues. The co‐expression of SIK2 and MYLK‐pS343 was associated with reduced median overall survival in human ovarian cancer samples. Taken together, SIK2 positively regulates ovarian cancer motility, migration and metastasis, suggesting that SIK2 is a potential candidate for ovarian cancer treatment.     

Annexin A1 is a potential biomarker of bone metastasis in small cell lung cancer

Small cell lung cancer (SCLC) is a subtype of lung cancer with a poor prognosis, with bone metastasis being one of the main causes of treatment failure. Therefore, investigating new biomarkers associated with bone metastasis may result in positive treatment outcomes. The present study detected the expression levels of annexin A1 (ANXA1) in the serum of 82 patients with SCLC using ELISA. ANXA1 expression in patients with SCLC with bone metastasis was significantly higher compared with that in patients without bone metastasis. Receiver operating characteristic analysis revealed that ANXA1 expression was significant in the diagnosis of bone metastasis in SCLC. ANXA1 was inhibited in SBC-5 cells and overexpressed in SBC-3 cells. Results revealed that ANXA1 was able to enhance SCLC cell proliferation, invasion, migration and bone adhesion in vitro. In vivo xenograft bone metastasis assays indicated that ANXA1 had the potential to promote the bone-metastasis ability of SCLC cells in NOD/SCID mice. Furthermore, ANXA1 increased parathyroid hormone-related protein secretion and enhanced Smad2 phosphorylation following TGF-β treatment in SCLC cells. Overall, ANXA1 may be involved in the pathogenesis of bone metastasis in SCLC and may be a potential biomarker for the diagnosis of SCLC.     

MiR-373 targeting of the Rab22a oncogene suppresses tumor invasion and metastasis in ovarian cancer

Metastasis is major cause of mortality in patients with ovarian cancer. MiR-373 has been shown to play pivotal roles in tumorigenesis and metastasis; however, a role for miR-373 in ovarian cancer has not been investigated. In this study, we show that the miR-373 expression is down-regulated in human epithelial ovarian cancer (EOC) and inversely correlated with clinical stage and histological grade. Ectopic overexpression of miR-373 in human EOC cells suppressed cell invasion in vitro and metastasis in vivo, and the epithelial–mesenchymal transition process. Silencing the expression of miR-373 resulted in an increased migration and invasion of EOC cells. Using integrated bioinformatics analysis, gene expression arrays, and luciferase assay, we identified Rab22a as a direct and functional target of miR-373 in EOC cells. Expression levels of miR-373 were inversely correlated with Rab22a protein levels in human EOC tissues. Rab22a knockdown inhibited invasion and migration of EOC cells, increased E-cadherin expression, and suppressed the expression of N-cadherin. Moreover, overexpression of Rab22a abrogated miR-373-induced invasion and migration of EOC cells. Taken together, these results demonstrate that miR-373 suppresses EOC invasion and metastasis by directly targeting Rab22a gene, a new potential therapeutic target in EOC.     

DUSP10对人卵巢癌A2780细胞迁移及侵袭的影响

目的：探讨DUSP10在浆液性卵巢癌组织中的表达情况及其与卵巢癌细胞迁移及侵袭能力的关系。方法：实时荧光定量PCR方法检测浆液性卵巢腺癌和正常输卵管伞端组织中 DUSP10的表达情况;转染DUSP10过表达和干扰质粒至人卵巢癌A2780细胞,划痕实验和Transwell实验观察癌细胞迁移及侵袭能力的变化。结果：DUSP10在浆液性卵巢癌组织的表达低于正常输卵管伞端组织（ P﹤0.05）。与对照组相比,转染DUSP10过表达质粒后A2780细胞迁移及侵袭能力受到抑制,转染DUSP10干扰质粒后A2780细胞迁移及侵袭能力增强。结论：DUSP10在浆液性卵巢癌组织中低表达;DUSP10可抑制人卵巢癌A2780细胞的迁移及侵袭能力。     

Inactivation of the WASF3 gene in prostate cancer cells leads to suppression of tumorigenicity and metastases

Background:

The WASF3 protein is involved in cell movement and invasion, and to investigate its role in prostate cancer progression we studied the phenotypic effects of knockdown in primary tumors and cell lines.

Methods:

ShRNA was used to knockdown WASF3 function in prostate cell lines. Cell motility (scratch wound assay), anchorage independent growth and in vivo tumorigenicity and metastasis were then compared between knockdown and wild-type cells.

Results:

Increased levels of expression were seen in high-grade human prostate cancer and in the PC3 and DU145 cell lines. Inactivation of WASF3 using shRNAs reduced cell motility and invasion in these cells and reduced anchorage independent growth in vitro. The loss of motility was accompanied by an associated increase in stress fiber formation and focal adhesions. When injected subcutaneously into severe combined immunodeficiency (SCID) mice, tumor formation was significantly reduced for PC3 and DU145 cells with WASF3 knockdown and in vivo metastasis assays using tail vain injection showed a significant reduction for PC3 and DU145 cells. The loss of the invasion phenotype was accompanied by down-regulation of matrix metalloproteinase 9.

Conclusions:

Overall, these observations demonstrate a critical role for WASF3 in the progression of prostate cancer and identify a potential target to control tumorigenicity and metastasis.     

膜联蛋白A2在癌症发生和进展中的作用

膜联蛋白A2是一种钙依赖性蛋白,它在各种类型肿瘤中起正向调节作用,在调节细胞功能上亦扮演多个角色,包括血管生成、增殖、凋亡、细胞迁移、入侵和粘附。膜联蛋白A2与血纤溶酶原以及细胞表面的组织纤溶酶原激活物结合,导致纤溶酶原转化成血纤维蛋白溶酶。血纤维蛋白溶酶是一种丝氨酸蛋白酶,可以激活基质金属蛋白酶和降解细胞外基质．对癌症转移发挥着关键作用。研究发现膜联蛋白A2在卵巢癌细胞中表达增多,能促进癌细胞转移。越来越多的证据表明,膜联蛋白A2及其结合蛋白在恶性肿瘤微环境中发挥重要作用,共同促进癌症的转移。本文综述了膜联蛋白A2及其结合蛋白在恶性肿瘤包括卵巢癌中的生物学作用。     

Mapping of two new epitopes on the apomucin encoded by MUC5AC gene: expression in normal GI tract and colon tumors

We have examined the role of the protein CD151 in cell motility, invasion and metastasis of cancer cells by using CD151-overexpressing cells prepared by transfection of CD151 cDNA into three cancer cell lines established from different origins; a human colon cancer RPMI4788, a human glioblastoma A172 and a human fibrosarcoma HT1080. Invasion into Matrigel and cell motility of all 3 CD151-overexpressing cancer cells were enhanced significantly when compared to control parental cells. Pulmonary metastasis of 2 metastatic CD151-overexpressing cancer cell lines, RPMI4788/CD151 and HT1080/CD151, was higher than that of control parental cells and was markedly inhibited by anti-CD151 monoclonal antibody (MAb), SFA1.2B4. To examine whether focal adhesion kinase (FAK) is associated with promotion of cell motility and invasion of cancer cells through CD151, we transfected human CD151 cDNA into FAK (+/+) or FAK (-/-) fibroblasts that were isolated from embryos in FAK-deficient mice and compared invasion into Matrigel and cell motility between each CD151-transfected cells and controls. The invasion into Matrigel and cell motility of CD151-transfected FAK (+/+) fibroblasts increased significantly above those of parental cells and were inhibited by anti-CD151 MAb, whereas those of CD151-transfected FAK (-/-) fibroblasts were not enhanced at all and were not blocked by anti-CD151 MAb. These findings indicate that the CD151 molecule enhances cell motility, invasion and metastasis of cancer cells and that FAK is needed for these events through CD151.     

The role of annexin A3 playing in cancers

Annexin family proteins are a well-known multigene family of Ca²⁺-regulated phospholipid- and membrane-binding proteins. As one of the annexin family genes/proteins, accumulated researches have begun to reveal that annexin A3 (Anxa3) exhibits important roles in tumor development, metastasis and drug resistance. The summarized research evidences in recent years indicate Anxa3 might specifically functionalize either as a tumor suppressor or as a tumor promoter candidate for different cancers depending on the types of tumor cells and tissues. The up-regulation of Anxa3 was found to be correlated with enhanced drug resistance of ovarian cancer, to promote the developments of colorectal adenocarcinoma and pancreatic carcinoma, and to facilitate the metastases of lung adenocarcinoma and hepatocarcinoma; meanwhile, the decreased Anxa3 expressions was negatively correlated with the developments of prostatic carcinoma and renal carcinoma. It is conceivable that Anxa3 could be regarded as a target for therapeutic intervention and a biological indicator for tumor development, invasion and metastasis as well as for the prognosis of tumor patients.     

High expression of small GTPase Rab3D promotes cancer progression and metastasis

Rab GTPases control exocytic and endocytic membrane trafficking such as exosomes release. As a secretory small GTPase, Rab3D is a vital regulator for protein secretion. However, the role of Rab3D in cancer was never systematically studied. The aim of this study is to examine its function and mechanism in cancer, especially metastasis. We detected protein levels of Rab3D in nine cancer cell lines and twelve types of clinical cancer specimens. Subsequently, we established in vitro migration and in vivo orthotopic metastatic mouse models to study the role of Rab3D in tumor metastasis. Here, we reported that the expression levels of Rab3D were dysregulated in cancer cells and highly correlated with tumor malignancies in the clinical samples. Increased expressions of Rab3D led to tumor invasion in vitro and lung metastasis in vivo, whereas Rab3D knockdown suppressed the tumor cell motility. Mechanistic studies revealed that Rab3D activated intracellular the AKT/GSK3β signaling to induce the EMT process. In addition, it also regulated the extracellular secretion of Hsp90α to promote tumor cell migration and invasion. These results prove that Rab3D is a key molecule to regulate tumor metastasis, suggesting that blocking the Rab3D function can be a potential therapeutic approach for cancer metastasis.