SHP2 promotes proliferation of breast cancer cells through regulating Cyclin D1 stabilityviathe PI3K/AKT/GSK3β signaling pathway

Objective:The tyrosine phosphatase SHP2 has a dual role in cancer initiation and progression in a tissue type-dependent manner.Several studies have linked SHP2 to the aggressive behavior of breast cancer cells and poorer outcomes in people with cancer.Nevertheless,the mechanistic details of how SHP2 promotes breast cancer progression remain largely undefined.Methods:The relationship between SHP2 expression and the prognosis of patients with breast cancer was investigated by using the TCGA and GEO databases.The expression of SHP2 in breast cancer tissues was analyzed by immunohistochemistry.CRISPR/Cas9 technology was used to generate SHP2-knockout breast cancer cells.Cell-counting kit-8,colony formation,cell cycle,and EdU incorporation assays,as well as a tumor xenograft model were used to examine the function of SHP2 in breast cancer proliferation.Quantitative RT-PCR,western blotting,immunofluorescence staining,and ubiquitination assays were used to explore the molecular mechanism through which SHP2 regulates breast cancer proliferation.Results:High SHP2 expression is correlated with poor prognosis in patients with breast cancer.SHP2 is required for the proliferation of breast cancer cellsin vitro and tumor growthin vivo through regulation of Cyclin D1 abundance,thereby accelerating cell cycle progression.Notably,SHP2 modulates the ubiquitin–proteasome-dependent degradation of Cyclin D1viathe PI3K/AKT/GSK3βsignaling pathway.SHP2 knockout attenuates the activation of PI3K/AKT signaling and causes the dephosphorylation and resultant activation of GSK3β.GSK3βthen mediates phosphorylation of Cyclin D1 at threonine 286,thereby promoting the translocation of Cyclin D1 from the nucleus to the cytoplasm and facilitating Cyclin D1 degradation through the ubiquitin–proteasome system.Conclusions:Our study uncovered the mechanism through which SHP2 regulates breast cancer proliferation.SHP2 may therefore potentially serve as a therapeutic target for breast cancer.

Role of Cyclin D1b in Inducing Macrophages Toward a Tumor-associated Macrophage-like Phenotype in Murine Breast Cancer

Objective:Tumor-associated macrophages(TAMs)of the M2 phenotype are frequently associated with cancer progression.Invasive cancer cells undergoing epithelial-mesenchymal transition(EMT)have a selective advantage as TAM activators.Cyclin D1b is a highly oncogenic splice variant of cyclin D1.We previously reported that cyclin D1b enhances the invasiveness of breast cancer cells by inducing EMT.However,the role of cyclin D1b in inducing macrophage differentiation toward tumor-associated macrophage-like cells remains unknown.This study aimed to explore the relationship between breast cancer cells overexpressing cyclin Dlb and TAMs.Methods:Mouse breast cancer 4T1 cells were transfected with cyclin D1b variant and co-cultured with macrophage cells in a Transwell coculture system.The expression of characteristic cytokines in differentiated macrophages was detected using qRT-PCR,ELISA and zymography assay.Tumor-associated macrophage distribution in a transplanted tumor was detected by immunofluorescence staining.The proliferation and migration ability of breast cancer cells was detected using the cell counting kit-8(CCK-8)assay,wound healing assay,Transwell invasion assay,and lung metastasis assay.Expression levels of mRNAs were detected by qRT-PCR.Protein expression levels were detected by Western blotting.The integrated analyses of The Cancer Genome Atlas(TCGA)datasets and bioinformatics methods were adopted to discover gene expression,gene coexpression,and overall survival in patients with breast cancer.Results:After co-culture with breast cancer cells overexpressing cyclin D1b,RAW264.7 macrophages were differentiated into an M2 phenotype.Moreover,differentiated M2-like macrophages promoted the proliferation and migration of breast cancer cells in turn.Notably,these macrophages facilitated the migration of breast cancer cells in vivo.Further investigations indicated that differentiated M2-like macrophages induced EMT of breast cancer cells accompanied with upregulation of TGF-β1 and integrinβ3 expression.Conclusion:Breast cancer cells transfected with cyclin D1b can induce the differentiation of macrophages into a tumor-associated macrophage-like phenotype,which promotes tumor metastasis in vitro and in vivo.

siRNA-cyclin D1对乳腺癌MCF-7细胞增殖的抑制作用

研究小干扰RNA(small interfering RNA,siRNA)对乳腺癌MCF-7细胞株cyclin D1表达的抑制及对细胞增殖的影响。化学合成针对cyclin D1基因的siRNA,转染MCF-7细胞株；分别应用荧光定量PCR和免疫印迹测定cyclin D1 mRNA和蛋白的表达,CCK-8测定细胞的增殖活性,流式细胞仪检测细胞周期,软琼脂培养检测细胞克隆形成能力。在实验中,10、50、100 nmol/L siRNA-cyclin D1分别使MCF-7细胞cyclin D1 mRNA表达降低了57．85%、63．22%和68．02%,蛋白表达降低了51．13%、62．09%、77．68%。转染siRNA-cyclin D1后,细胞增殖受到抑制,细胞周期阻滞于G1期,软琼脂克隆形成率降低。结果提示siRNA可以有效抑制MCF-7细胞株中cyclin D1的表达,使细胞周期阻滞于G1期,从而抑制细胞增殖。

人细胞周期蛋白cyclin D_1基因RNAi表达载体的构建与鉴定

[目的]构建针对人细胞周期蛋白cyclinD1基因的RNAi真核表达载体,检测其对人卵巢癌HO-8910细胞cyclinD1基因表达的干扰效率。[方法]以cyclinD1为靶向设计,合成的4条互补寡核苷酸链克隆至pSUPER载体中,得到重组质粒pSUPER-C1￣4,行双酶切分析后测序鉴定;运用脂质体介导转染HO-8910细胞,G418筛选;采用RT-PCR检测对cyclinD1基因mRNA表达的干扰,并筛选有效的siRNA干扰序列。[结果]经酶切测序鉴定证实,重组质粒中已插入目的序列;RT-PCR表明有4个重组载体均不同程度抑制目的基因的转录,但以pSUPER-C2的干扰效率最强。[结论]在卵巢癌细胞系筛选出有效干扰cyclinD1基因表达siRNA序列,成功构建针对cyclinD1基因的RNAi真核表达载体有效抑制目的基因的表达。

siRNA对乳腺癌细胞CyclinE表达和生长抑制作用

研究siRNA对乳腺癌MCF-7细胞株cyclinE表达的抑制及对细胞生长的影响。化学合成针对cyclinE基因的小干扰RNA(siRNA),转染MCF-7细胞株;分别应用荧光定量PCR和免疫印迹测定cyclinEmRNA和蛋白质的表达,CCK-8测定细胞的增殖活性,流式细胞仪检测细胞周期,软琼脂培养检测细胞克隆形成能力。10、50、100nmol/LsiRNA-cyclinE分别使MCF-7细胞cyclinE基因表达降低了24.7%、62.5%和71.0%,蛋白质表达降低了40.8%、66.5%和71.3%。转染siRNA-cyclinE后,G1期细胞增多,S期减少,增殖受到抑制,软琼脂克隆形成率降低。结果提示,在MCF-7细胞株中,导入针对cyclinE的siRNA,可有效抑制cyclinE的表达,进而使细胞增殖减缓,逆转其恶性表型。

Effect of Estrogen on Telomerase Activity in Human Breast Cancer Cells

To investigate the effects of estrogen(E 2) on telomerase activity and its mechanism in human breast cancer cells, estrogen receptor positive MCF-7 cells were treated with different concentrations of E 2 Telomerase activity was measured by using TRAP-ELISA method, the cell cycle phases analyzed by using flow cytometry, and the expression of Cyclin D 1 detected by using immunohistochemistry method The results showed that telomerase activity levels were increased in MCF-7 cells treated with 10 -8 mol/L E 2 during the observed period ( P <0 05), and E 2 increased telomerase activity levels in a dose-dependent manner(10 -10 -10 -8 mol/L); Simultaneously, the cell cycle phases of MCF-7 cells treated with 10 -8 mol/L E 2 were changed significantly: G 0/G 1 phase decreased from 60 52% to 50 93%, S phase increased from 29 03% to 30 83%; However, the expression of Cyclin D 1 was decreased It was concluded that estrogen can upregulate telomerase activity of MCF-7 cells, and the effect can be blocked by antiestrogen tamoxifen Its mechanism may be closely associated with modulation of cell cycle phases

Geldanamycin inhibits proliferation and motility of Her2/neu-overexpressing SKBr3 breast cancer cells

Objective Benzoquinone ansamycin antibiotic, geldanamycin (GA), is a new anticancer agent that could inhibit Hsp90 by occupying its NH2-terminal ATP-binding site. This study was to investigate the antitumor efficacy of GA on Her2/neu tyrosine kinase overexpressing human breast cancer cell line SKBr3. Methods The degradation of Her2/neu tyrosine kinase was analyzed by Western blotting, the proliferation index was determined by MTT assay, cell cycle distribution was detected by flow cytometry, Cyclin D1 mRNA transcription was measured by RT-PCR and real-time PCR, and cell motility was evaluated by the cell culture insert model. Results GA induced a dose-and a time-dependent degradation of the Her2/neu tyrosine kinase protein and concurrently, the inhibition of cancer cell proliferation. The antitumor effects mediated by GA included: GA treatment decreased the survival rates of cancer cells, and led to a dose-dependent G1 arrest. Furthermore, this antitumor effect was proved to be related to declined transcription of Cyclin D1. Concurrently, the motility of cancer cells was reduced by GA. Conclusion GA treatment could induce the degradation of Her2/neu tyrosine kinase efficiently, inhibit cancer cell proliferation and reduce motility in Her2/neu tyrosine kinase overexpressed human breast cancer cell line SKBr3.

乳腺恶性肿瘤组织中Cyclin D_1的表达与临床病理相关性

目的 探讨细胞周期素D1 (CyclinD1 )在乳腺肿瘤组织中的表达及临床病理相关性。方法 采用免疫组化SP法检测 78例乳腺恶性肿瘤及 1 7例乳腺良性病变石蜡包埋标本CyclinD1 表达。结果 CyclinD1 在乳腺恶性肿瘤细胞核中呈棕黄色染色 ,于核边缘近核膜处浓集 ,阳性表达率 44.87% ,其中在导管内原位癌 (DCIS) 5 /7例及叶状囊肉瘤 1 /1例中阳性表达。CyclinD1 表达与患者雌激素受体 (ER)显著相关 (P <0 .0 5 ) ,而与年龄、病理类型、组织学分级、淋巴结状态、肿瘤大小等无关 (P >0 .0 5 )。生存分析资料显示CyclinD1 (+)、(- )两组 5年相对复发危险度 (RRR)u =1 .95 9(P >0 .0 5 ) ,Kaplan Meier生存曲线示两组 5年累积无复发生存期 (RFS)无显著差异 (P >0 .0 5 )。结论 ①CyclinD1 在乳腺癌发展初期即异常表达 ,有助于从分子水平鉴别原位癌与非典型增生 ,但其表达与肿瘤分化及恶性进展无关。②CyclinD1 表达与ER相关 ,可能有助于判断内分泌治疗敏感性。③CyclinD1 的表达与预后无关。

Cyclin D1在不同分子亚型乳腺癌中的表达及其对预后的影响

目的检测cyclin D1在不同分子亚型乳腺癌中的表达,分析其表达与临床病理特征和预后的关系。方法采用免疫组织化学法检测175例乳腺癌组织标本中cyclin D1的表达情况,应用卡方检验分析cyclin D1在不同分子亚型乳腺癌中的表达,采用Spearman秩相关方法分析cyclin D1表达与临床病理特征的相关性,运用Kaplan-Meier生存曲线分析cyclin D1不同表达对预后的影响。结果①Cyclin D1阳性表达在Luminal A型所占比例最高(P<0.05),而cyclin D1阴性表达在Luminal B型所占比例最高(P<0.05)。②Cyclin D1阳性表达与临床分期、组织学分级及PR无关(P>0.05),与淋巴结转移数目(rs=0.197,P<0.01)、ER呈正相关(rs=0.139,P<0.05);cyclin D1阳性表达与Her-2呈负相关(rs=-0.131,P<0.05)。③Cyclin D1阳性表达越强,无瘤生存时间越长(P<0.05)。结论 Cyclin D1阳性表达与ER、Her-2及淋巴结转移数目有明显相关性,且其阳性表达提示相对良好的预后,可作为乳腺癌预后评估的参考指标。