Loss of A-type lamin expression compromises nuclear envelope integrity in breast cancer

Through advances in technology,the genetic basis of cancer has been investigated at the genomic level,and many fundamental questions have begun to be addressed.Among several key unresolved questions in cancer biology,the molecular basis for the link between nuclear deformation and malignancy has not been determined.Another hallmark of human cancer is aneuploidy;however,the causes and consequences of aneuploidy are unanswered and are hotly contested topics.We found that nuclear lamina proteins lamin A/C are ...     

KGF在人NSCLC中的表达及意义

目的：探讨KGF mRNA之于肺癌，尤其是非小细胞肺癌(NSCLC)发生的意义。方法：采用原位杂交法检测KGF mRNA在50例非小细胞肺癌中的表达，井将其与正常组织对照。结果：NSCLC中KGF mRNA阳性率达86％．明显高于正常肺组织（P＜0.05)．KGF mRNA阳性主要表现为问质细胞细胞质着色．少数肿瘤实质细胞细胞质亦有着色。结论：NSCLC中存在KGF mRNA高表达，KGF可通过旁分泌、自分泌两种方式发挥作用。KGF可能与上皮源性的NSCLC的发生相关。     

Mutation analysis and mRNA expression of trail-receptors in human breast cancer

The chromosome region 8p12-p22 shows frequent allelic loss in a variety of human malignancies, including breast cancer (BC). The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-receptors TRAIL-R1, -R2, -R3 and -R4 are located on 8p21-p22 and might be candidate tumor suppressor genes in this region. To evaluate the involvement of TRAIL receptors in breast carcinogenesis, we have analyzed the entire coding region of TRAIL-R2 and the death domain (DD) regions of TRAIL-R1 and -R4 for the detection of somatic mutations in a series of breast tumors, lymph node metastases and BC cell lines. Overall, we detected 1, 11 and 3 alterations in the TRAIL-R1, -R2 and -R4 genes, respectively. Although functional studies have not yet been performed, we assume that most of these alterations do not alter the function of TRAIL-receptors. Additionally, we analyzed individuals from BC families for the detection of TRAIL-R2 germline mutations. One alteration has been found in the Kozak consensus motif at position -4 with respect to the translation initiation AUG [1-4 (C-->A)]. We further studied the mRNA expression of TRAIL and the 4 TRAIL receptors. In BC cell lines, a strongly decreased mRNA expression of TRAIL, TRAIL-R1, -R3 and -R4 was found, whereas the expression of TRAIL-R2 was only slightly reduced. In breast tumors, a 1.2-3.6-fold reduction of mRNA signals of the 5 genes was observed. No correlation was found between the expression level of TRAIL and the receptor mRNAs and clinicopathologic variables and between the expression of TRAIL-R2 and TP53 mutation status and loss of heterozygosity (LOH) at 8p21-p22. Taken together, we cannot exclude the involvement of TRAIL-receptors in BC. Our mutation studies indicate that DD receptor mutations occur at low frequency and are not the primary cause for the altered mRNA expression of TRAIL and TRAIL-receptors in BC.     

类泛素化neddylation修饰调控乳腺癌中核纤层蛋白lamin B1的表达

背景与目的:类泛素化neddylation修饰在乳腺癌中的作用鲜有报道。该研究的前期研究发现,抑制neddylation修饰可诱导乳腺癌细胞发生衰老,但具体机制尚未完全阐明。研究报道核纤层蛋白lamin B1缺失可导致细胞衰老。本研究旨在探讨在乳腺癌中,neddylation修饰与lamin B1是否存在相关性及其可能的机制。方法:利用113例乳腺癌患者肿瘤组织制成的组织芯片对neddylation修饰过程中关键蛋白神经前体细胞表达发育下调蛋白8(neural precursor cell expressed developmentally downregulated protein 8,NEDD8)、NEDD8活化酶E1(NEDD8-activating enzyme 1,NAE1)及核纤层蛋白lamin B1进行免疫组织化学染色。采用Spearman rank分析NEDD8和NAE1与lamin B1表达的相关性。采用CRISPR/Cas9技术敲低NEDD8的表达以阻断neddylation修饰,采用蛋白质印迹法(Western blot)检测neddylation修饰对Lamin...     

Insulin-like growth factor II mRNA expression in human breast cancer

Insulin-like growth factor II is a growth factor important in fetal development. Several cancer tissues and cell lines have been reported to express IGF-II and rat IGF-II is mitogenic for breast cancer cell lines. Using Northern analysis and ribonuclease protection assays, IGF-II mRNA was detected in normal fibroblasts and in the established breast cancer cell line, T47D. In this cell line, steady state levels of IGF-II message were increased by treatment with estradiol. 10 nM IGF-II, purified from human serum, was mitogenic for breast cancer cell lines. In vitro, IGF-II may act as an autocrine growth factor for some cell lines. RNA derived from breast cancer, pathologically normal breast tissue, and benign breast disease also contained IGF-II mRNA. When paired samples of normal and cancer tissue were obtained from the breast of the same patient, the level of IGF-II mRNA expression in the normal tissue was at least that found in the cancer. This is consistent with previous observations that show IGF-II is expressed in mesenchyme. These findings suggest that in breast cancer IGF-II is produced by stromal tissue elements and potentially by the malignant epithelial cells. Therefore, IGF-II may function as an autocrine or a paracrine growth factor in different breast tumors.     

Prognostic implications of securin expression and sub-cellular localization in human breast cancer

Purpose

Securin belongs to a class of cell cycle regulators that prevent metaphase-to-anaphase transition until sister chromatid separation is complete. Evidence is accumulating that securin has a prognostic impact on a variety of malignancies but, thus far, the role and regulation of securin expression and its sub-cellular localization have not been systematically addressed in breast cancer.

Methods

In total 470 breast cancer specimens with follow-up data for up to 22 years were included. Immunohistochemical staining and immunofluorescence double-staining were performed for securin and its regulating proteins PTTG1IP, CDC20 and BUBR1. Prognostic associations were evaluated between the expression patterns of these proteins and established prognosticators of invasive breast cancer and patient survival.

Results

We found that a high fraction of securin expressing cancer cells predicted an unfavorable clinical outcome of the breast cancer patients (p?<?0.001). Also in multivariate analyses, the fraction of securin expressing cancer cells served as an independent prognosticator of a poor survival (p?<?0.0001). We also found that the sub-cellular localization of securin exhibited prognostic power, since cytoplasmic securin expression in the cancer cells appeared to be associated with aggressive breast cancer subtypes and high breast cancer-associated mortality rates (p?=?0.003). Through immunofluorescence double-staining, we found that PTTG1IP, CDC20 and BUBR1 exhibited distinct patterns of co-expression with securin, suggesting a regulatory role in the metaphase-to-anaphase transition in human breast cancer cells. We also noted that a subgroup of triple-negative breast carcinomas exhibited deviant expression patterns for the proteins studied.

Conclusions

Our data indicate that securin expression may serve as a strong and independent prognosticator of breast cancer outcome and that a cytoplasmic localization of the protein may provide additional prognostic information, particularly in the biologically and clinically challenging subgroup of triple-negative breast carcinomas. The sub-cellular localization of securin appears to reflect the expression of PTTG1IP, CDC20 and BUBR1, which may participate in the regulation of securin activity and, ultimately, in the survival of breast cancer patients.

     

Mammary expression of xenobiotic metabolizing enzymes and their potential role in breast cancer

Breast cancer is the major cause of cancer death in women worldwide. High penetrance genes account for only 5% of cases, whereas polymorphic low penetrance genes acting in concert with lifestyle/environmental risk factors are likely to account for a much higher proportion. Genotoxic compounds implicated in human breast carcinogenesis include endogenous compounds, estrogens, and dietary or environmental xenobiotics-heterocyclic amides, aromatic amines, polycyclic aromatic hydrocarbons, and nitropolycyclic aromatic hydrocarbons. Here we review evidence for a role of mammary-expressed enzymes that metabolically activate and/or detoxify potential genotoxic breast carcinogens: cytochrome P-450s, catechol-O-methyltransferase, epoxide hydrolase, peroxidases, glutathione S-transferases, N-acetyltransferases, sulfotransferases, and other enzymes catalyzing conjugation reactions. This information is particularly relevant in the light of evidence for the presence of genotoxic agents that require metabolic activation in mammary lipid, in nipple aspirates and in breast milk, and for the presence of DNA adducts in human mammary epithelial cells (from which most breast carcinomas originate). The effect of polymorphisms in the genes encoding these enzymes on breast cancer risk are also considered. The evidence for the role of genotoxic carcinogens in the etiology of breast cancer is compelling, but mammary-specific enzyme expression should be taken into account when considering the contribution of polymorphisms to risk.     

Hormone-dependent nuclear localization of the tyrosine kinase iyk in the normal human breast epithelium and loss of expression during carcinogenesis

iyk, a member of the frk family of non-receptor tyrosine kinases, was originally isolated from normal mouse mammary glands and is characterized by a nuclear localizing signal within the SH2 domain. We have investigated the expression and subcellular localization of iyk in the normal human breast and in malignant breast diseases. Immuno-histochemical analyses revealed that in normal tissue iyk localizes to both cytoplasmic and nuclear compartments of breast epithelial cells. The subcellular distribution was dependent on the hormonal state, being mostly cytoplasmic during the follicular, proliferative phase of the menstrual cycle, whereas frequent nuclear staining was observed in the resting stages during the luteal phase and, most prominently, after menopause. Strikingly, invasive carcinomas, irrespective of tumor type or hormonal status of the patient, exhibited almost complete loss of iyk expression in both the cytoplasm and the nucleus. In contrast, in situ breast carcinomas from post-menopausal patients showed a clear reduction of the nuclear iyk localization while retaining cytoplasmic staining. Our results indicate that iyk expression is gradually lost during carcinogenesis; thus, iyk may be classified as a tumor-suppressor gene.     

Demonstration of adiponectin receptors 1 and 2 mRNA expression in human breast cancer cells

Recently, we have shown that low adiponectin levels are significantly associated with an increased breast cancer risk. It seems to be very important to study the expression of adiponectin receptor 1 (AdipoR1) and receptor 2 (AdipoR2) in the human breast epithelial cells and breast cancer cells in order to clarify whether or not adiponectin exerts its effects directly on these cells. Expression of adiponectin, AdipoR1, and AdipoR2 mRNA was determined by RT-PCR assay using the RNA samples obtained from human breast cancer cell lines (MCF-7, T47D, SKBR3, and MDA-MB231), HMEC (primary culture of normal human mammary epithelial cells), adipose tissues (axilla) as well as breast cancer cells and normal breast epithelial cells selectively collected from breast cancer tissues by laser microdissection (LMD). Adiponectin mRNA expression was observed only in the adipose tissues. On the other hand, AdipoR1 and AdipoR2 mRNA expression was observed in all four breast cancer cell lines, HMEC, adipose tissues as well as breast cancer cells and normal breast epithelial cells selectively collected by LMD. In addition, AdipoR1 and AdipoR2 expression in both normal breast epithelial cells and breast cancer cells was confirmed by immunohistochemistry. These results suggest a possibility that adiponectin might modulate the growth of normal breast epithelial cells and breast cancer cells directly through AdipoR1 and AdipoR2 receptors, and that the association of low serum adiponectin levels with a high breast cancer risk might be explained, at least in part, by the direct effect of adiponectin on the breast epithelial cells.     

同源异型盒基因HOXD10在乳腺癌组织中的表达及其临床病理意义

背景与目的：乳腺癌是威胁女性健康最常见的恶性肿瘤之一,从分子水平深入研究其癌变机制,对寻找新的标志基因具有重要意义.本研究探讨同源异型盒基因HOXD10基因在乳腺癌发生、发展进程中的可能作用.方法：以18s rRNA基因作为参照,采用荧光实时定量RT-PCR技术,以相对定量方法检测44例乳腺癌组织及16例乳腺良性病变组织中HOXD10 mRNA表达情况.结果：HOXD10在乳腺癌中的表达显著低于乳腺良性病变组织.组织学分级为Ⅲ级的乳腺癌标本中H0XD10 mRNA的表达显著低于组织学Ⅰ、Ⅱ级标本.H0XD10 mRNA的表达与淋巴结转移、肿瘤大小、TNM分期之间相关性不显著.结论：HOXD10基因在乳腺癌中呈低表达甚至表达缺失,由于这种基因可能为乳腺癌发生发展的抑制因素,因此对其我们应给予更多关注.     

同源异型盒基因BP1在乳腺癌组织中的表达及其临床意义

背景与目的BP1(beta-protein1)基因是新近发现的转录因子,定位于染色体17q21-22,属同源异型盒基因DLX家族,在急性髓系白血病和急性T淋巴细胞白血病中均呈过度表达。本研究通过观察BP1mRNA在乳腺癌中的表达情况,分析并探讨其与乳腺癌临床病理特征的关系。方法以β-actin基因作为参照,应用逆转录聚合酶链反应(RT-PCR)技术,检测82例乳腺肿瘤组织、12例近端肿瘤旁组织和10例远端癌旁组织中BP1mRNA的表达。结果82例肿瘤组织中有53例BP1阳性(64.63%),而在近端癌旁组和远端癌旁组中则表达很弱(16.67%)或不表达(0%),差异具有统计学意义(P<0.05)。BP1基因的过表达与组织学分级有关(P<0.05),而与肿瘤大小、有无淋巴结转移、病理类型、肿瘤家族史、初潮年龄、初产年龄、怀孕次数、绝经状况、雌激素受体及孕酮受体状态无关。结论BP1基因在部分乳腺癌中上调,其表达与肿瘤组织学分级有关。     

The role of histamine in human mammary carcinogenesis: H3 and H4 receptors as potential therapeutic targets for breast cancer treatment

There is increasing evidence that describes a histamine role in normal and cancer cell proliferation. To better understand the importance of histamine in breast cancer development, the expression of histamine H3 (H3R) and H4 (H4R) receptors and their association with proliferating cell nuclear antigen (PCNA), histidine decarboxylase (HDC) and histamine content were explored in mammary biopsies. Additionally, we investigated whether H3R and H4R were implicated in the biological responses triggered by histamine in MDA-MB-231 breast cancer cells. The expression levels of H3R, H4R, PCNA, HDC and histamine content were determined by immunohistochemistry in 40 benign and malignant lesions. MDA-MB-231 cells proliferation (clonogenic assay and BrdU incorporation) and cell cycle distribution (flow cytometry) were evaluated upon treatment with histamine, H3R and H4R agonists and antagonists. Apoptosis was determined by Annexin staining and TUNEL assay. Cell migration was assessed by transwell system. Results indicate that H3R was detected in 67% (10/15) of benign lesions and in almost all carcinomas (24/25), being the level of its expression significantly higher in carcinomas (p = 0.0016). The non-tumoral breast tissue surrounding carcinomas revealed a lower H3R expression compared to the tumor cells. Only 13% (2/15) of the benign lesions expressed H4R compared to 44% (11/25) of the carcinomas. Interestingly, H3R expression was correlated in carcinomas with the expression of HDC and PCNA (p < 0.0001), and also histamine content (p = 0.0229). Accordingly, histamine increased MDA-MB-231 cells proliferation and also migration via H3R. In contrast, activation of H4R inhibited proliferation and this effect was associated with an arrest in the G(0)/G(1) phase of the cell cycle and an induction of apoptosis. Present findings demonstrate the presence of H3R and H4R in human mammary tissue and suggest that H3R may be involved in the regulation of breast cancer growth and progression representing a novel molecular target for new therapeutic approach.