NOTCH1 signaling promotes chemoresistance via regulating ABCC1 expression in prostate cancer stem cells

Chemotherapy is a strategy for patients with advanced prostate cancer, especially those with castration-resistant prostate cancer. Prostate cancer stem cells (PCSCs) are believed to be the origin of cancer recurrence following therapy intervention, including chemotherapy. The mechanisms underlying the chemoresistance of PCSCs are still poorly understood. In the present study, fluorescence-activated cell sorting was used to isolate PCSCs from LNCaP and PC3 cell lines. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide was used to measure the cell viability. Quantitative real-time PCR and western blotting were utilized to evaluate the mRNA and protein levels. ShRNA was employed to knock down target gene expression. Chromatin immunoprecipitation (ChIP) was performed to explore the detailed mechanism underlying ABCC1 expression. Our results revealed that the sorted PCSCs showed enhanced chemoresistance ability than matched non-PCSCs. Protein level of activated form of NOTCH1(ICN1) was significantly higher in PCSCs. Inhibition of NOTCH1 with shRNA could decrease ABCC1 expression, and improve chemosensitivity in PCSCs. Finally, ChIP–PCR showed ICN1 could directly bind to the promoter region of ABCC1. In conclusion, NOTCH1 signaling could transactivate ABCC1, resulting in higher chemoresistance ability of PCSCs, which might be one of the important mechanisms underlying the chemoresistance of PCSCs.     

HN1L promotes migration and invasion of breast cancer by up-regulating the expression of HMGB1

Recent reports showed that haematological and neurological expressed 1-like (HN1L) gene participated in tumorigenesis and tumour invasion. However, the expression and role of HN1L in breast cancer remain to be investigated. Here, bioinformatics, western blot and immunohistochemistry were used to detect the expression of HN1L in breast cancer. Wound healing, transwell assay, immunofluorescence assay and mass spectrum were used to explore the role and mechanism of HN1L on the migration and invasion of breast cancer, which was confirmed in vivo using a nude mice model. Results showed that HN1L was significantly over-expressed in breast cancer tissues, which was positively correlated with M metastasis of breast cancer patients. Silencing HN1L significantly inhibited the invasion and metastasis of breast cancer cells in vitro and lung metastasis in nude mice metastasis model of breast cancer. Mechanistically, HN1L interacted with HSPA9 and affected the expression of HMGB1, playing a key role in promoting the invasion and metastasis of breast cancer cell. These results suggested that HN1L was an appealing drug target for breast cancer.     

Osteopontin promotes hepatocellular carcinoma invasion by up-regulating MMP-2 and uPA expression

Osteopontin (OPN) is over-expressed in a variety of cancers, but its role in hepatocellular carcinoma (HCC) progression has not been clarified. In this study, weakly tumorigenic, non-metastastic human HCC cell line SMMC-7721 cells were forced to over-express OPN via stable transfection. A series of functional assays were performed to assess the effects of OPN on tumor cell behaviors and cDNA microarray was used to identify the genes regulated by OPN. The results showed that OPN significantly enhanced the migration and invasion of SMMC-7721 cells in vitro. In addition, CD44v6 antibody could significantly inhibit the invasion of OPN over-expressing SMMC-7721 cells. Moreover, MMP-2 and uPA expressions were significantly up-regulated in OPN over-expressing SMMC-7721 cells. Together, these findings indicate that OPN enhanced HCC cells invasion through interaction with its receptor CD44v6 and increased MMP-2 and uPA expressions, providing at least one mechanism for OPN-mediated HCC progression and metastasis.     

前列腺癌DU145细胞相关蛋白在构建体内三维空间模型中的表达研究

目的探讨前列腺癌相关蛋白在胶原、琼脂糖、基质胶、海藻酸钠加明胶4种支架材料培养的前列腺癌DU145细胞中的表达水平。方法将前列腺癌DU145细胞按照一定比例接种至胶原、琼脂糖、基质胶、海藻酸钠加明胶4种支架材料中,分别分组进行移植瘤模型的三维培养,然后采用免疫组化方法检测MMP9、FN1、Laminin等3个前列腺癌相关蛋白在3种支架材料中培养的DU145细胞构建移植瘤模型后培养的组织中表达情况。结果 MMP9在有支架材料培养的前列腺癌DU145中蛋白表达高于无支架材料培养的组织;FN1在海藻酸钠加明胶组中蛋白表达阴性,在琼脂糖与胶原组中蛋白表达阳性且明显强于空白组;Lamininm在空白组与海藻酸钠加明胶组中均表达阳性,但明显低于胶原、琼脂糖、基质胶组的强阳性。结论采用支架材料的三维培养体系优于无支架材料的二维培养体系。胶原为体内前列腺癌DU145细胞三维培养的最优支架材料。     

Valproic acid inhibits the invasion of PC3 prostate cancer cells by upregulating the metastasis suppressor protein NDRG1

Valproic acid (VPA) is a clinically available histone deacetylase inhibitor with promising anticancer attributes. Recent studies have demonstrated the anticancer effects of VPA on prostate cancer cells. However, little is known about the differential effects of VPA between metastatic and non-metastatic prostate cancer cells and the relationship between the expression of metastasis suppressor proteins and VPA. In the present study, we demonstrate that inhibition of cell viability and invasion by VPA was more effective in the metastatic prostate cancer cell line PC3 than in the tumorigenic but non-metastatic prostate cell line, RWPE2. Further, we identified that the metastasis suppressor NDRG1 is upregulated in PC3 by VPA treatment. In contrast, NDRG1 was not increased in RWPE2 cells. Also, the suppressed invasion of PC3 cells by VPA treatment was relieved by NDRG1 knockdown. Taken together, we suggest that the anticancer effect of VPA on prostate cancer cells is, in part, mediated through upregulation of NDRG1. We also conclude that VPA has differential effects on the metastasis suppressor gene and invasion ability between non-metastatic and metastatic prostate cancer cells.     

hsa-miR-125a-5p通过上调Rock-1表达促进胃癌细胞侵袭

摘要：目的 探讨hsa-miR-125a-5p表达对胃癌细胞侵袭能力的影响及其作用机制。方法 在胃癌MKN45细胞株中瞬时转染hsa-miR-125a-5p-mimics使其表达明显上调,采用Transwell侵袭实验检测细胞的侵袭能力。然后,通过micRNA靶基因预测软件获得hsa-miR-125a-5p的潜在靶基因Rock-1,以抗体阻断及Western blot进行验证。结果 与对照组相比,经瞬时转染后hsa-miR-125a-5p在胃癌MKN45细胞株中表达明显增加;Western blot结果显示hsa-miR-125a-5p表达上调后Rock-1表达明显上调,Transwell实验结果表明MKN45细胞的侵袭能力明显增强（P<0.05）。而hsa-miR-125a-5p表达上调后阻断Rock-1表达,细胞的侵袭能力明显减弱（P<0.05）。结论 hsa-miR-125a-5p促进胃癌细胞的侵袭,其机制与Rock-1通路有关。     

miRNA-191对前列腺癌的增殖、迁移侵袭能力的影响及其机制

目的:观察miRNA-191对前列腺癌的增殖、迁移和侵袭能力的影响,并探讨其机制。方法:分别检测4种人前列癌细胞系(PC-3、DU-145、LNCa P、22RU1)及人正常前列腺细胞RWPE-2中miRNA-191的表达水平,并选择前列腺癌细胞系PC-3作为实验对象。将PC-3细胞分为3组:空白对照组(不转染)、miRNA-191 NC组(Inhibitor NC转染PC-3细胞)、miRNA-191 Inhibitor组(miRNA-191 Inhibitor转染PC-3细胞),每组设置3个复孔。采用RTq PCR法检测PC-3细胞miRNA-191和PLCD1的mRNA表达水平;采用CCK8法检测PC-3细胞增殖水平;采用划痕实验和侵袭实验分别检测PC-3细胞迁移能力和侵袭能力;通过Targetscan靶基因预测网站,筛选PLCD1作为miRNA-191的靶向蛋白,并用双荧光素酶靶标实验验证;采用Western blot法检测PC-3细胞PLCD1的蛋白表达。结果:与RWPE-2细胞相比,人前列癌细胞中mi NRA-191的表达水平显著升高(P<0.05),且miRNA-1...     

TLR4 signaling promotes the expression of VEGF and TGFbeta1 in human prostate epithelial PC3 cells induced by lipopolysaccharide

Chronic inflammation promotes tumor development and progression, and Toll-like receptors (TLRs) may play an important role in this process. In this study, we found that human prostate epithelial PC3 cells constitutively express TLR4 in mRNA and protein level. lipopolysaccharide (LPS) promotes the expression and secretion of immunosuppressive cytokine TGFβ₁ and proangiogenic factor VEGF in human prostate epithelial PC3 cells. We further elucidated that functionally activation of TLR4 is essential for the increased VEGF and TGFβ₁ mRNA expression in the cells. In addition, after LPS stimulation, the increased expression of NF-_KB p65 protein was also detected in human PC3 cells. Our results demonstrate that TLR4 expressed on human PC3 cells is functionally active, and may play important roles in promoting prostate cancer immune escape, survival, progression, and metastasis by inducing immunosuppressive and proangiogenic cytokines.     

Degradation of DRAK1 by CUL3/SPOP E3 Ubiquitin ligase promotes tumor growth of paclitaxel-resistant cervical cancer cells

Despite favorable responses to initial chemotherapy, drug resistance is a major cause limiting chemotherapeutic efficacy in many advanced cancers. However, mechanisms that drive drug-specific resistance in chemotherapy for patients with advanced cancers are still unclear. Here, we report a unique role of death-associated protein kinase-related apoptosis-inducing kinase 1 (DRAK1) associated with paclitaxel resistance in cervical cancer cells. Interestingly, DRAK1 protein level was markedly decreased in paclitaxel-resistant cervical cancer cells without affecting its mRNA expression, which resulted in an increase in tumor necrosis factor receptor-associated factor 6 (TRAF6) expression, as well as an activation of TRAF6-mediated nuclear factor-kappa B (NF-κB) signaling cascade, thereby promoting tumor progression. DRAK1 depletion markedly increased the chemotherapeutic IC₅₀ values of paclitaxel in cervical cancer cells. Ectopic expression of DRAK1 inhibited growth of paclitaxel-resistant cervical cancer cells in vitro and in vivo. Furthermore, DRAK1 was markedly underexpressed in chemoresistant cervical cancer patient tissues compared with chemosensitive samples. We found that DRAK1 protein was destabilized through K48-linked polyubiquitination promoted by the Cullin scaffold protein 3 (CUL3) / speckle-type POZ (poxvirus and zinc finger protein) protein (SPOP) E3 ubiquitin ligase in paclitaxel-resistant cells. Collectively, these findings suggest that DRAK1 may serve as a potential predictive biomarker for overcoming paclitaxel resistance in cervical cancer.Subject terms: Cancer therapeutic resistance, Ubiquitylation     

miR-145靶向调控DAB2对前列腺癌PC3细胞迁移和侵袭能力的影响

已有研究表明, miR-145在多种肿瘤中低表达, 并与细胞增殖和转移相关。文章通过生物信息学分析并结合体外实验鉴定, 发现DAB2(Disabled homolog 2)为miR-145在肿瘤转移过程中累及的新靶点。DAB2一直被认为是一个重要的抑癌基因, 在多种肿瘤标本中表达低下。然而, 研究发现, 在具高侵袭能力的前列腺癌细胞株PC3中DAB2基因却呈较高水平表达。另外, 外源表达miR-145能显著下调 DAB2表达水平, 并抑制PC3细胞的迁移和侵袭能力, 且这种miR-145诱导的PC3细胞功能缺陷能被DAB2过表达修复。上述结果表明, miR-145能通过靶向调控DAB2而影响高侵袭前列腺癌细胞的迁移和侵袭能力。     

METTL16 promotes cell proliferation by up-regulating cyclin D1 expression in gastric cancer

N6-methyladenosine (m6A) is a well-known modification of RNA. However, as a key m6A methyltransferase, METTL16 has not been thoroughly studied in gastric cancer (GC). Here, the biological role of METTL16 in GC and its underlying mechanism was studied. Immunohistochemistry was used to detect the expression of METTL16 and relationship between METTL16 level and prognosis of GC was analysed. CCK8, colony formation assay, EdU assay and xenograft mouse model were used to study the effect of METTL16. Regulatory mechanism of METTL16 in the progression of GC was studied through flow cytometry analysis, RNA degradation assay, methyltransferase inhibition assay, RT-qPCR and Western blotting. METTL16 was highly expressed in GC cells and tissues and was associated with prognosis. In vitro and in vivo experiments confirmed that METTL16 promoted proliferation of GC cells and tumour growth. Furthermore, down-regulation of METTL16 inhibited proliferation by G1/S blocking. Significantly, we identified cyclin D1 as a downstream effector of METTL16. Knock-down METTL16 decreased the overall level of m6A and the stability of cyclin D1 mRNA in GC cells. Meanwhile, inhibition of methyltransferase activity reduced the level of cyclin D1. METTL16-mediated m6A methylation promotes proliferation of GC cells through enhancing cyclin D1 expression.     

Knockdown of MACC1 expression suppressed hepatocellular carcinoma cell migration and invasion and inhibited expression of MMP2 and MMP9

Expression of MACC1 (metastasis-associated in colon cancer-1) protein is associated with metastasis of various human cancers. This study analyzed MACC1 protein expression in hepatocellular carcinoma (HCC) tissue specimens and then investigated the effects of MACC1 knockdown on HCC cell migration and invasion, and gene expression levels. Sixty pairs of HCC and adjacent normal liver tissues from HCC patients were analyzed for MACC1 expression immunohistochemically. The HCC cell lines Hep3B, Huh7, MHCC97H, SMMC-7721, Bel-7402, and HepG2 and the normal liver cell line LO2 were used to assess expressions of MACC1 mRNA and MACC1 protein using qRT-PCR and western blot, respectively. MACC1 short hairpin RNA (shRNA) was used to knockdown MACC1 protein expression in Huh7 cells. Changes in the tumor phenotype of these cells were analyzed with wound healing assay and invasion assays, and differences in gene expression were evaluated via western blot. Immunofluorescence was used to locate MACC1 protein in the above cell lines. MACC1 was highly expressed in HCC tissues and the nuclear expression of MACC1 protein was associated with poor tumor differentiation and intrahepatic metastasis or portal invasion. Moreover, MACC1 mRNA and MACC1 protein was also expressed in HCC cell lines. Immunostaining showed that MACC1 protein was localized in both nuclei and cytoplasm of HCC cell lines and the nuclear localization of MACC1 protein was associated with increased aggressiveness of HCC in cell lines. Knockdown of MACC1 expression using MACC1-shRNA reduced Huh7 cell migration and invasion abilities, which was associated with downregulation of MMP2, MMP9, and c-Met proteins in Huh7 cells. Localization of MACC1 protein to the nucleus may predict HCC progression. Knockdown of MACC1 expression using MACC1 shRNA warrants further evaluation as a novel therapeutic strategy for control of HCC.     

Epb41l3 suppresses esophageal squamous cell carcinoma invasion and inhibits MMP2 and MMP9 expression

EPB41L3 may play a role as a metastasis suppressor by supporting regular arrangements of actin stress fibres and alleviating the increase in cell motility associated with enhanced metastatic potential. Downregulation of epb41l3 has been observed in many cancers, but the role of this gene in esophageal squamous cell carcinoma (ESCC) remains unclear. Our study aimed to determine the effect of epb41l3 on ESCC cell migration and invasion. We investigated epb41l3 protein expression in tumour and non‐tumour tissues by immunohistochemical staining. Expression in the non‐neoplastic human esophageal cell line Het‐1a and four ESCC cell lines – Kyse150, Kyse510, Kyse450 and Caes17 – was assessed by quantitative Polymerase Chain Reaction (qPCR) and Western blotting. Furthermore, an EPB41L3 overexpression plasmid and EPB41L3‐specific small interfering RNA were used to upregulate EPB41L3 expression in Kyse150 cells and to downregulate EPB41L3 expression in Kyse450 cells, respectively. Cell migration and invasion were evaluated by wound healing and transwell assays, respectively. The expression levels of p‐AKT, matrix metalloproteinase (MMP)2 and MMP9 were evaluated. Expression of epb41l3 was significantly lower in tumour tissues than in non‐tumour tissues and in ESCC cell lines compared with the Het‐1a cell line. Kyse450 and Caes17 cells exhibited higher expression of epb41l3 than Kyse150 and Kyse510 cells. Overexpressing epb41l3 decreased Kyse150 cell migration and invasion, whereas EPB41L3‐specific small interfering RNA silencing increased these functions in Kyse450 cells. Furthermore, overexpressing epb41l3 led to downregulation of MMP2 and MMP9 in Kyse150 and Kyse510 cells. Our findings reveal that EPB41L3 suppresses tumour cell invasion and inhibits MMP2 and MMP9 expression in ESCC cells. Copyright © 2016 John Wiley & Sons, Ltd.     

WAVE3 promotes cell motility and invasion through the regulation of MMP-1, MMP-3, and MMP-9 expression

WAVE3 is a member of the WASP/WAVE family of proteins, which play a critical role in the regulation of actin polymerization, cytoskeleton organization, and cell motility. We show here that knockdown of the WAVE3 protein, using RNA interference in MDA-MB-231 cells, decreases phospho-p38 MAPK levels, but not those of phospho-AKT, phospho-ERK, or phospho-JNK. Knockdown of WAVE3 expression also inhibited the expression levels of MMP-1, MMP-3, and MMP-9, but not MMP-2. MMP production could be restored by PMA treatment, without affecting siRNA-mediated WAVE3 knockdown. The WAVE3-mediated downregulation of p38 activity and MMP production is independent of the presence of both WAVE1 and WAVE2, whose expression levels were not affected by loss of WAVE3. We also show that the downstream effect of the WAVE3 knockdown is the inhibition of cell motility and invasion, coupled with increased actin stress fiber formation, as well as reorganization of focal adhesion complexes. These findings suggest that WAVE3 regulates actin cytoskeleton, cell motility, and invasion through the p38 MAPK pathway and MMP production.