Wistar大鼠自发性乳腺肿瘤细胞系的建立及其生物学特性

目的 从Wistar大鼠自发性乳腺肿瘤中分离出乳腺肿瘤细胞系(ZHL2006),并对其进行鉴定,为动物模型的开发、肿瘤发病机制的探讨提供有价值的线索.方法 对一例Wistar大鼠自发性乳腺腺癌瘤组织进行培养.对传代培养细胞进行细胞生长曲线测定、细胞形态结构分析、细胞染色体分析,检测广谱细胞角蛋白(PCK)表达、软琼脂集落形成实验等检测.将细胞接种于10只裸鼠,并对形成的肿瘤进行病理组织学检查,并进行分离培养.结果 ZHL2006细胞在体外生长迅速,群体倍增时间为43.6 h;倒置显微镜及Giemsa染色镜下观察细胞为多边形及梭形;透射电镜观察可见细胞表面有微绒毛,核高度不规则,核浆比例增大,核仁明显等;染色体数目和结构异常,具有癌细胞特性.广谱细胞角蛋白(PCK)染色阳性,说明其自上皮而非来自基质;同时ZHL2006细胞系在软琼脂中可形成克隆,具裸鼠致瘤性.该乳腺肿瘤细胞系经体外长期培养后已形成永生化细胞系,并具有明显的恶性细胞表型.裸鼠接种实验成功率为6/10,复制肿瘤细胞和原发肿瘤形态结构一致,细胞培养形态结构一致.结论 本研究成功的建立了大鼠乳腺肿瘤细胞系,该细胞系具有典型的恶性肿瘤特征,能应用于裸鼠并成功复制出乳腺肿瘤模型.     

东方田鼠与昆明小鼠乳腺癌细胞表面特征比较

目的　通过对封闭群东方田鼠 (Microtusfortis)和昆明小鼠乳腺癌细胞扫描电镜特征的观察 ,旨在了解两者之间的差异。方法　将乳腺癌肿块与经产正常东方田鼠乳腺以及昆明小鼠自发性乳腺癌肿块作常规扫描电镜。结果　正常东方田鼠乳腺的腺管结构规则 ,可见分散的乳腺细胞 ,乳腺细胞表面有许多皱褶和不规则的小丘状突起 ,状如桑椹 ,无明显可见的微绒毛 ;东方田鼠乳腺癌的腺管结构不规则 ,细胞表面密布微绒毛 ,微绒毛长而不规则 ,末端成松叶状 ;昆明小鼠乳腺癌的组织中散布有大量带有微绒毛的癌细胞 ,其微绒毛特点为密而短 ,末端为圆纯状。结论　东方田鼠与昆明小鼠乳腺癌细胞表面呈现不同的微绒毛特征     

阿帕替尼调节VEGF/MAPK/NF-kB信号通路抑制大鼠非小细胞肺癌的机制

[目的]探讨阿帕替尼调节VEGF/MAPK/NF-kB抑制大鼠非小细胞肺癌的机制。[方法]制备人肺腺癌A549细胞悬液经背部穿刺构建大鼠非小细胞肺癌模型,给予大鼠50 mg/kg阿帕替尼连续灌胃14 d。观察非小细胞肺癌大鼠的自主活动次数、肿瘤体积、体质量以及肺组织病理改变;采用免疫组织化学法检测大鼠肺组织中VEGFR-2蛋白的表达;采用Western Blot法检测甲状腺癌癌组织中VEGF、p-p38、p-MAPK、NF-kB、Bcl-2和Bax蛋白的表达。[结果]与模型组对比,治疗组瘤体质量下降,肿瘤抑制率升高明显(P<0.05)。治疗组及模型组的肺癌细胞表现出岛状生长,细胞的轮廓不清晰甚至消失,且大小不一,密集生长,形态差异大,间质出现大量的散状浸润的中性粒细胞;治疗组的癌细胞表现为核染色质边集、皱缩,发生程度不同的片状坏死区。癌组织中的VEGFR-2蛋白平均光密度水平下降明显(P<0.05)。和模型组对比,治疗组的VEGF、p-p38、p-MAPK、NF-kB和Bax蛋白表达明显升高,Bcl-2含量显著降低(P<0.05)。[结论]阿帕替尼可通过调节VEGF/MAPK/NF-kB信号通路抑制大鼠非小细胞肺癌,抑制肿瘤组织内新生血管的形成,并促进癌细胞的凋亡。     

大豆凝集素的纯化及其凝集不同肿瘤细胞的探讨

大豆凝集素 (SBA)能特异识别N 乙酰氨基半乳糖 (GalNAc)或半乳糖 (Gal) ,引起兔红细胞凝集[1] .正常人体细胞表面糖链上的GalNAc或Gal通常被唾液酸分子覆盖 ,不能被SBA识别 .新近研究表明 ,能被SBA特异识别的异常糖链可在多种恶性肿瘤细胞上表达 ,包括 :大鼠乳腺癌细胞系R32 30AC[2 ] ,小鼠乳腺肿瘤细胞系TPDMT 4 [3 ] ,小鼠T细胞肝转移淋巴瘤L5 178Y F9、SL2 5 [4] ,小鼠Lewis肺癌细胞[5] ,人类结肠癌细胞系HT2 9、SW12 2 2 [6] ,人类胰腺癌细胞系Hup T3、Hup T4 [7] ,人类乳腺癌细胞系T 4 7D[8] ,附睾乳头状囊腺癌[9] …     

乳腺浸润性微乳头状癌的研究现状

乳腺浸润性微乳头状癌(IMPC)是乳腺浸润性癌的一种特殊类型,其发生率低,临床表现及影像学特征与普通的乳腺浸润性导管癌没有显著区别。这种病理类型可与普通浸润性导管癌混合出现,也可表现为单纯的浸润性微乳头状癌。但浸润性微乳头状癌具有独特的组织学形态及分子结构,决定了其病理学分级较高、易于发生淋巴结转移的侵袭性生物学行为特点。多数浸润性微乳头状癌在影像学上表现为边缘不清的不规则肿块影,常伴有微小钙化。其特征性病理形态为细胞膜上皮抗原(EMA)在肿瘤细胞簇外周的细胞和基质中腔隙边缘特异性染色,同时显微镜下瘤细胞表面发现微绒毛结构,说明了瘤细胞簇周围的空隙样结构实际上是管状腔隙,瘤细胞呈"极向倒转"方式排列。IMPC具有高度淋巴血管浸润倾向,局部复发率高,是一种预后较差的类型。本文对近年来关于乳腺浸润性微乳头状癌的研究进展进行了综述。     

乳腺X 线摄影癌周透亮带的影像特征及其病理基础与价值

目的:研究乳腺X线摄影癌周透亮带影像学特征,分析其病理基础及临床意义。方法:回顾性分析2010年6月-2011年10月期间我院经手术病理证实为乳腺癌患者196例,筛选出术前进行过乳腺X线摄影检查并且图像上癌周出现透亮带征象的患者共47例51个病灶,测量肿块直径、癌周透亮带宽度等,与病理大体标本切面和镜下切片进行对比研究分析。结果:双乳病灶多分布于外上象限(19/51),临床触诊病灶大小平均值约35.45±1.25 mm。乳腺X摄影观察病灶均为肿块样,影像测量病灶大小平均值约20.49±1.18 mm,与临床触诊大小之间的差别具有统计学意义(t=2.85,P<0.01);肿块周围可观察到宽窄不均透亮带,平均宽度约15.07±0.86 mm,乳腺癌癌周透亮带宽度与肿块大小之间没有显著相关性(r=0.188,P=0.186)。病理大体标本观察病灶周围包绕一圈连续的黄色脂肪组织;HE染色镜下切片观察瘤灶周围为一圈成熟脂肪细胞,局部被瘤灶边缘增生的致密结缔组织为主的毛刺分割,脂肪组织中散在分布炎性细胞,部分区域见灶状癌细胞团浸润。结论:乳腺X线摄影癌周透亮带病理基础为伴随瘤周间质反应的富含脂肪的组织层,此征象对乳腺癌的诊断、以及临床评估肿瘤浸润范围具有一定意义。     

Cep55在基底细胞样乳腺癌中的表达及其临床意义

目的:探讨中心体相关蛋白Cep55在基底细胞样型乳腺癌中的表达及其与基底细胞样型乳腺癌临床病理特征的关系.方法:选取本院收集的66例基底细胞样型乳腺癌和66例癌旁正常乳腺组织标本后,运用石蜡包埋、切片后,采用免疫组化法(EnVision二步法)检测Cep55的表达,并分析其与基底细胞样型乳腺癌临床病理特征之间的相关性.结果:(1)基底细胞样型乳腺癌和癌旁正常乳腺组织中Cep55的阳性表达率分别为74.2％和16.7％,差异有统计学意义(P＜0.05).(2)不同的年龄、绝经与否、肿块大小的基底细胞样型乳腺癌患者Cep55的表达无明显差异(P＞0.05),不同TNM分期、淋巴结转移与否的基底细胞样型乳腺癌患者Cep55的表达比较差异有显著统计学意义(P＜0.05).结论:Cep55的表达上调与基底细胞样型乳腺癌的发生和发展有关.     

乳腺小管癌12例临床病理及免疫组织化学分析

目的探讨乳腺小管癌的临床病理特征、诊断与鉴别诊断要点。方法对12例乳腺小管癌进行临床病理分析、组织形态学及免疫组化染色观察,结合文献对其临床表现、病理形态特点及鉴别诊断进行探讨。结果乳腺小管癌12例(单纯型8例、混合型4例),组织形态学特征为肿瘤均由高分化的小管结构组成,管腔形状不规则成角状,衬覆单层上皮细胞,未见肌上皮细胞及完整的基底膜成分,SMA(-)。间质增生并富于细胞。12例中9例随访6个月到4年,均无复发。结果 乳腺小管癌是一种由高分化小管结构组成的特殊类型乳腺癌,预后良好,可能是保乳手术的最佳适应证。     

单独及混合胶原酶消化小鼠乳腺癌移植瘤组织获取细胞活性比较

[目的]比较单独及混合胶原酶消化小鼠乳腺癌移植瘤组织后获取的细胞活性。[方法]用4T1细胞建立小鼠乳腺癌动物模型,待成瘤后取乳腺癌肿瘤组织。比较4种消化酶(Ⅰ型胶原酶、Ⅳ型胶原酶、Ⅰ+Ⅳ型混合胶原酶和商用胶原酶),两种消化方法:单酶或多酶单次消化30 min;单酶或多酶分次消化30 min。用碘化丙啶(PI)染色各组消化后的细胞悬液,流式细胞仪检测细胞活率。[结果]不同酶单次消化后的细胞活率分别为:Ⅰ型胶原酶为55. 5±7. 2%、Ⅳ型胶原酶为26. 9±7. 6%、Ⅰ+Ⅳ型混合胶原酶为43. 5±10%、商用胶原酶为30. 4±10. 6%;在分次消化后分别为:Ⅰ型胶原酶为70. 6±4. 1%、Ⅳ型胶原酶为65. 5±17. 2%,Ⅰ+Ⅳ型混合胶原酶为78. 3±2. 2%,商用胶原酶为48. 5±11. 6%。[结论]使用Ⅰ+Ⅳ型混合胶原酶分次消化得到的乳腺癌移植瘤细胞活性最高,并为小鼠乳腺癌移植瘤组织消化提供了一种有效的新方法。     

乳腺导管内乳头状瘤、非典型乳头状瘤与导管内乳头状癌诊断与鉴别诊断

目的:探讨乳腺导管内乳头状癌和导管内乳头状瘤、非典型乳头状瘤的病理表现及诊断与鉴别诊断.方法:对20例乳腺导管内乳头状癌及23例导管内乳头状瘤、5例非典型导管内乳头状瘤进行大体及镜下病理学分析及免疫组化分析,并结合文献对其病理表现、病理形态特点及鉴别诊断进行探讨.结果:20例乳腺导管内乳头状癌HE染色表现为导管明显扩张,有真性乳头,乳头之轴心由纤维血管束组成,乳头覆盖细胞有多种形式,但真正的肌上皮是缺如的.免疫组化SMA/p63显示局部或完全的肌上皮细胞消失,CEA85%的乳头状癌阳性.23例导管内乳头状瘤乳头存在肌上皮层,免疫组化结果与导管内乳头状癌相反.5例非典型乳头状瘤局部(＜1/3的区域)显示有不典型上皮增生,局部有肌上皮缺失.结论:乳腺导管内乳头状癌是一种具有乳头状癌样结构基础上的原位恶性上皮增生,但无浸润的癌.预后好于其他型导管原位癌,免疫标记SMA、p63和CEA可以帮助该肿瘤的诊断及与乳腺导管内乳头状瘤、非典型导管内乳头状瘤鉴别诊断.     

Expression of transforming growth factor alpha (TGF alpha) in differentiated rat mammary tumors: estrogen induction of TGF alpha production

Primary well-differentiated dimethylbenzene alpha-anthracene (DMBA)-or nitrosomethylurea (NMU)-induced rat mammary adenocarcinomas that are estrogen dependent possess biologically active and immunoreactive transforming growth factor alpha (TGF alpha), which can be detected in a sort agar growth-promoting assay and by a specific liquid-phase competitive RIA, respectively. In contrast, tissue extracts prepared from transplantable undifferentiated DMBA-I and NMU-II rat mammary carcinomas that are estrogen independent and metastatic exhibit low or undetectable levels of TGF alpha. In addition, the primary DMBA- and NMU-induced rat mammary adenocarcinomas express a specific 4.8-kilobase TGF alpha mRNA species, whereas little or no TGF alpha mRNA can be detected in the transplantable DMBA-I and NMU-II tumors. Primary tumors synthesize type IV basement membrane collagen, whereas the transplantable tumors elaborate very little type IV collagen. Either TGF alpha or estrogens can differentially enhance the synthesis of type IV collagen by 0.5- to 4-fold over total protein synthesis in primary cultures of normal mouse mammary epithelial cells or in primary NMU-induced tumor cells, respectively. Therefore, TGF alpha could function as an estrogen-inducible autocrine growth factor for well differentiated rat mammary tumor cells by its ability to selectively regulate type IV collagen synthesis. Estrogens can modulate TGF alpha production in vivo in primary DMBA-induced rat mammary tumors, because ovariectomy results in a rapid decline (within 6 h) of TGF alpha mRNA levels. This response to estrogens can also be observed in vitro. Primary DMBA- or NMU-induced rat mammary tumor cells cultured in the presence of 17 beta-estradiol (10(-8) M) for 4 days show an increase in the level of TGF alpha mRNA over cells not treated with estrogen. This increase in TGF alpha mRNA is paralleled by a 2- to 3-fold increase in the levels of immunoreactive TGF alpha that can be detected and in the conditioned medium from estrogen-treated cells. These results suggest that TGF alpha may be an adjunct marker for those mammary tumors that are well differentiated adenocarcinomas and estrogen dependent and that estrogen-independent tumors do not constitutively produce TGF alpha or express TGF alpha mRNA.     

Immunocytochemical localization of insulin- and somatostatin-like material in human breast tumors

Four types of human breast lesions and C3H mouse mammary adenocarcinomas (type A) were examined for the immunocytochemical localization of cells containing hormone-like substances. Insulin- or somatostatin-like immunoreactive material was observed in scattered single cells and nests of tumor cells in seven of eight infiltrating duct carcinomas, and in the majority of tumor cells from an anaplastic carcinoma. A few somatostatin-immunoreactive cells were observed in only one of seven fibroadenomas studied. No immunoreactive cells were observed in mouse adenocarcinomas or in human breast dysplasias. These results suggest that cells with hormone-like immunoreactivity may be a common feature in two types of malignant human breast tumors.     

Keratin-like proteins in normal and neoplastic cells of human and rat mammary gland as revealed by immunofluorescence microscopy

Normal and neoplastic human breast tissue as well as lactating and nonlactating rat mammary glands and 7,12-dimethylbenz(alpha)-anthracene-induced mammary adenocarcinomas of rat, were examined by indirect immunofluorescence microscopy using guinea pig antibodies to human and bovine epidermal prekeratin and to cytokeratin polypeptide D from mouse hepatocytes. In normal mammary glands of both species, lactating rats included, the antibodies raised against human and bovine epidermal prekeratins strongly stained ductal and myoepithelial cells, whereas antibodies to hepatic cytokeratin D revealed, in addition, fibrillar staining in cells of the alveolus-like terminal lobular units and in milk secreting cells of the rat. The presence of some finely dispersed intermediate-sized filaments of the cytokeratin type in lactating alveolar cells of rat mammary gland was also demonstrated by electron microscopy. In human intraductal mammary carcinomas the antibodies to epidermal prekeratins showed staining in myoepithelial cells and intralumenal papillary protrusions of the tumor, whereas the antibodies to hepatic cytokeratin D presented an almost complementary pattern in that they showed strongest staining in the more basally located layers of tumor cells. Intraductal adenocarcinomas of rats showed strong staining with all keratin antibodies examined. In contrast to previous studies using exclusively antisera raised against epidermal prekeratin, out results show that all types of neoplastic and non-neoplastic epithelial cells of mammary gland of both species contain-at least some-filaments of the cytokeratin type identifiable by immunologic reaction, if antibodies are used that recognize a broad range of epidermal and nonepidermal cytokeratins. Consequently, such broad range antibodies to keratin-like proteins provide adequate tools to identify and characterize neoplastic and non-neoplastic epithelial cells and to eliminate false negative immunocytochemical findings in tumor diagnosis. In addition, our observation that in the same human carcinoma two cell types can be distinguished by their reaction with two different antibodies to cytokeratins from epidermis and liver, respectively, indicates that the cells of a given carcinoma can differ in their cytoskeletal composition, thus presenting further criteria for diagnostic differentiation.     

Daunorubicin-induced DNA lesions in isolated rat hepatocytes and mammary epithelial cells

Daunorubicin, an anticancer drug, induces primarily mammary adenocarcinoma in Sprague-Dawley rats. We investigated daunorubicin-induced DNA lesions in enzymatically isolated mammary epithelial cells and hepatocytes from 7-8-week-old female Sprague-Dawley rats. Differences were observed in the type and quantity of DNA lesions in mammary epithelial cells and hepatocytes as determined by alkaline elution analysis. DNA single-strand breaks and proteinase-K-sensitive cross-linking lesions were observed in mammary epithelial cells. Hepatocytes appeared to have significantly lower relative frequencies of single-strand breaks than mammary epithelial cells when treated with daunorubicin (1.5-10.0 micrograms/10(6) cells). Hepatocytes displayed two types of cross-link. One form was sensitive to proteinase-K digestion, whereas the other form was insensitive. The metabolism of daunorubicin to the aglycone metabolites was substantially lower in mammary cells than in hepatocytes. However, the total uptake of the drug was similar in these two cell types. A metabolite, 7-deoxydaunorubicinol aglycone, was unable to induce single-strand breaks or cross-linking lesions in mammary epithelial cells. Both cell types exhibited a similar ability to repair radiation-induced single-strand breaks of DNA. However, the mammary cells may be less able to repair daunorubicin-mediated DNA damage. These results revealed that mammary epithelial cells are less able to metabolize the active mutagen/carcinogen, daunorubicin, than are hepatocytes. This, coupled with the observations of greater apparent DNA damage in mammary cells, may be of primary importance in the drug-induced carcinogenicity in the rat mammary tissue.     

Double primary lung cancers: with special reference to their exfoliative cytology and to the rare, malignant "mixed" tumor of the salivary-gland type

Two autopsy cases are reported in which double primary cancers of the lung had been strongly or definitely suspected before death by demonstration of two different types of malignant cells in the sputum as well as in smears of aspirates from pleural fluid and/or mediastinal tumor. By exfoliative cytology, one case was characterized by carcinoma cells of the small-cell type plus the large-cell and/or adenocarcinoma type; the other displayed small-cell-type and squamous-cell-type malignant cells. The autopsies definitely revealed in the first case an anaplastic carcinoma of the small-cell type in the left bronchus and a salivary-gland-type malignant "mixed" tumor in the right lower lobe and in the second case an anaplastic carcinoma of the small-cell type in the right upper lobe and a squamous-cell carcinoma in the left upper lobe. The frequence of occurrence and pathologic diagnosis of double primary lung cancers are reviewed and discussed. A rare type of lung cancer, salivary-gland-type malignant "mixed" tumor, is given special reference.     

Characterization of a monoclonal antibody for human aldo-keto reductase AKR1C3 (type 2 3alpha-hydroxysteroid dehydrogenase/type 5 17beta-hydroxysteroid dehydrogenase); immunohistochemical detection in breast and prostate

Human aldo-keto reductase AKR1C3 (type 2 3alpha-hydroxysteroid dehydrogenase/type 5 17beta-hydroxysteroid dehydrogenase) catalyzes the reduction of Delta(4)-androstene-3,17-dione to yield testosterone, the reduction of 5alpha-dihydrotestosterone to yield 3alpha- and 3beta-androstanediol, and the reduction of estrone to yield 17beta-estradiol. Relatively, high mRNA expression of AKR1C3 was found in human prostate and mammary gland where it is implicated in regulating ligand access to the androgen and estrogen receptor, respectively. AKR1C3 shares high sequence identity >86% with related plastic human 20alpha-hydroxysteroid dehydrogenases (AKR1C1), type 3 3alpha-hydroxysteroid dehydrogenase (AKR1C2) and type 1 3alpha-hydroxysteroid dehydrogenase (AKR1C4), and reagents are urgently needed to discriminate between these enzymes at the mRNA, protein and functional level. We describe the characterization of a high-titer isoform specific monoclonal antibody (Ab) for AKR1C3. It does not cross react with human AKR1C1, AKR1C2 or AKR1C4, human aldehyde reductase AKR1A1 or rat 3alpha-hydroxysteroid dehydrogenase (AKR1C9) on immunoblot analysis. The monoclonal Ab can be used to detect AKR1C3 expression by immunohistochemistry in sections of paraffin-embedded mammary gland and prostate. In the breast enzyme staining was detected in ductal carcinoma in situ where the cancerous cells were strongly immunoreactive. In normal prostate immunoreactivity was limited to stromal cells with only faint staining in the epithelial cells. In adenocarcinoma of the prostate elevated staining was observed in the endothelial cells and carcinoma cells. The reagent thus has utility to access the localized expression of AKR1C3 in hormonal dependent malignancies of the breast and prostate.     

ALDH1-High Ovarian Cancer Stem-Like Cells Can Be Isolated from Serous and Clear Cell Adenocarcinoma Cells,and ALDH1 High Expression Is Associated with Poor Prognosis

Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are defined as a small population of cancer cells that have high tumorigenicity. Furthermore, CSCs/CICs are resistant to several cancer therapies, and CSCs/CICs are therefore thought to be responsible for cancer recurrence after treatment and distant metastasis. In epithelial ovarian cancer (EOC) cases, disease recurrence after chemotherapy is frequently observed, suggesting ovarian CSCs/CICs are involved. There are four major histological subtypes in EOC, and serous adenocarcinoma and clear cell adenocarcinoma are high-grade malignancies. We therefore analyzed ovarian CSCs/CICs from ovarian carcinoma cell lines (serous adenocarcinoma and clear cell adenocarcinoma) and primary ovarian cancer cells in this study. We isolated ovarian CSCs/CICs as an aldehyde dehydrogenase 1 high (ALDH1^high) population from 6 EOC cell lines (3 serous adenocarcinomas and 3 clear cell adenocarcinomas) by the ALDEFLUOR assay. ALDH1^high cells showed greater sphere-forming ability, higher tumorigenicity and greater invasive capability, indicating that ovarian CSCs/CICs are enriched in ALDH1^high cells. ALDH1^high cells could also be isolated from 8 of 11 primary ovarian carcinoma samples. Immunohistochemical staining revealed that higher ALDH1 expression levels in ovary cancer cases are related to poorer prognosis in both serous adenocarcinoma cases and clear cell adenocarcinoma cases. Taken together, the results indicate that ALDH1 is a marker for ovarian CSCs/CICs and that the expression level of ALDH1 might be a novel biomarker for prediction of poor prognosis.     

G1 cell cycle regulatory proteins in chemically-induced rat mammary adenocarcinomas in vivo and tumor promotion-sensitive, -resistant and transformed mouse epidermal cells in vitro

Tumor promotion is characterized by selective proliferation of initiated cells resulting in their clonal expansion. Cyclin Dl is frequently upregulated in this process, but its expression does not necessarily correlate positively with cyclin A. In the present article, expression of G1 cell cycle regulatory proteins was systematically analyzed using two models of carcinogenesis: (a) N-methyl-N-nitrosourea (MNU)-induced rat mammary adenocarcinomas and normal rat mammary epithelial cells in vivo and (b) promotion-sensitive, -resistant, and transformed JB6 mouse epidermal cells in vitro. The results of this analysis revealed that p27Kipl negatively correlated with cyclin Dl. In addition, there were two types of correlations between p27Kipl and cyclin A. First, p27Kipl negatively correlated with cyclin A (type-l correlation). This scenario was observed in normal rat mammary epithelial cells in vivo and promotion-sensitive (P+) JB6 mouse epidermal cells, stimulated with phorbol ester (TPA) in vitro. Second, p27Kipl positively correlated with cyclin A (type-ll correlation). This correlation was observed in MNU-induced rat mammary adenocarcinomas in vivo and TPA-stimulated (P+) JB6 cells, treated with retinoic acid in vitro.     

Electrophysiological study of coupling between cultured cells of the mouse mammary gland in five distinct physiological states.

Electrical coupling has been observed between cultured cells of the mouse mammary gland in five distinct physiological or pathological states. We have employed young primary cultures of cells dissociated from the following tissues: normal glands from young virgin or midpregnant females, hyperplastic alveolar nodules (believed to be precancerous) transplanted in gland-free mammary fat pads, and spontaneous mammary adenocarcinomas and their pulmonary metastases. All successfully impaled pairs of cells (a total of 97 pairs) were found to be ionically coupled. Furthermore, in normal and tumor cell cultures, electrical coupling was observed between dome-dome and dome-nondome cell pairs. This study correlates with electronmicroscopic studies of fresh normal, hyperplastic, and tumor samples, which show the presence of gap junctions in all three.