Amplification of the c-yes oncogene in canine mammary tumors

Genomic DNAs of 14 mammary tumors were analyzed by Southern blot hybridization using a human c-yes-1 oncogene probe. The amplification was successful in half of the cases (7 adenocarcinomas). The degree of amplification was approximately 4-fold, and a high proportion was seen in malignant tumors. In addition, DNA polymorphism was detected in two adenocarcinomas.     

Cellular immunity to canine mammary tumor cells demonstrated by the leucocyte migration technique.

Cellular immunity to canine mammary tumor cells was studied by means of the leucocyte migration technique (LMT). Intact tumor cells, separated either by enzymatical or mechanical disruption, were used as antigen, and efforts were made to cultivate tumor cells in vitro. Fifteen female tumorous dogs were studied, and 12 non-tumorous mainly male dags were used as controls. Leucocytes from tumor-bearing females were mixed with own autologous or foreign homologous tumor cells, and control leucocytes were presented with cells from the same source. In addition, leucocytes from tumorous animals and controls were mixed.Animal group A comprised 8 tumor-bearing females. In this group mixtures of different cell numbers and different tumor cell/leucocyte ratios were tried. Animal group B comprised 7 tumor-bearing females, and 40 × 10⁶ leucocytes from these were mixed with 2 × 10⁶ antigencells, antigen-cell/leucocyte ratio 0.05. A great number of tumor cells (tumor cell/leucocyte ratio > 0.05) caused strong non-specific inhibition of leucocyte migration, but in spite of marked inhibition (< 61%) in the homologous system in animal group A, inhibition in the autologous system was found to be stronger (72.2–92.3%). In animal group B, dogs presented with own tumor cells showed marked inhibition (23.7–90.1%), while the controls showed a migration inhibition below 20%. Mixtures of homologous leucocytes showed inhibition of the same order as mixtures of control leucocytes and tumor cells. Thus evidence of cellular immunity against own canine mammary tumor cells was obtained. It proved difficult to cultivate the tumor cells for more than 2–3 passages. Some evidence of antigenic cross reactivity was obtained between 2 adenocarcinomas. Enzymatical separation of tumor cells did not seem to alter antigenic characteristics of the cell surface. Mechanical separation, however, proved to be simpler, more rapid and yielded cell suspensions largely free of debris, and is therefore recommended for further work.     

Immunohistochemical analysis of c-yes and c-erbB-2 oncogene products and p53 tumor suppressor protein in canine mammary tumors

In order to evaluate the involvement of c-yes and c-erbB-2 oncogene products, and p53 tumor suppressor protein in canine mammary neoplastic lesions, sections of archived paraffin-embedded samples of 79 mammary tumors were analyzed immunohistochemically using antibodies against human c-yes p62 and c-erbB-2 products and p53. These 79 tumors were divided into 2 groups: 32 benign (2 adenosis, 7 simple adenomas, 14 complex adenomas, and 9 benign mixed mammary tumors) and 47 malignant tumors (26 simple adenocarcinomas, 7 complex adenocarcinomas, 5 solid carcinomas, 2 sclerosing carcinomas, 6 malignant mixed mammary tumors, and 1 malignant myoepithelioma). As a result of immunostaining, 40.6% (13/32) of the benign tumors and 21.3% (10/47) of the malignant tumors expressed the c-Yes oncogene product, ErbB-2 expression was detected in 50% (16/32) of the benign tumors and in 19.1% (9/47) of the malignant tumors. P53 expression was detected in 16% (4/25) of the benign tumors and in 30.6% (11/36) of the malignant tumors. Co-expression of c-Yes and ErbB-2, ErbB-2 and p53, and all 3 products was detected in 6, 1 and 7 tumors, respectively.     

The expression of carbonic anhydrase in canine mammary gland and mammary gland tumor

Carbonic anhydrase (CA), a metallo-enzyme containing zinc, broadly distributes in mammalian tissues and participates in physiological regulation such as respiration, acid-base balance, ion transport, bone resorption, as well as the development of tumor by the reversible hydration of carbon dioxide. However the expression of CA in the tissue of mammary gland tumor was not documented. In this study we examine the histolocalization and gene expression of CA in both normal canine mammary gland tissue and mammary gland tumor by histochemical examination, and RT-PCR. Four mRNA expression of CA isoenzymes, such as CA II, IV, VI and IX were found under RT-PCR analysis and different band patterns were found between normal canine mammary tissue and canine mammary gland tumor tissue. CA II, IV, VI and IX gene mRNA expression were found in the normal mammary gland tissue, indicating CA II, IV, VI and IX are likely to be the essential enzymes to maintain the normal physiological condition of canine mammary gland tissue cells. However the expression of CA IV was not found in the tissue of malignant mammary gland tumor that may become the marker for the prognostic recognition of canine mammary gland tumor.     

MicroRNA-21 expression,serum tumor markers,and immunohistochemistry in canine mammary tumors

Background

Canine mammary tumors (CMTs) are one of the most common malignancies in dogs and are associated with significant mortality. Serum tumor markers and non-coding microRNAs have gained widespread popularity in human oncology studies. The present study has two aims, first one is to investigate the miR-21 expression compared with changes in serum tumor markers (CEA and CA15-3) in CMT. The second aim is to detect the immunohistochemistry markers as vimentin, P63, and -SMA in CMT.

Methods

This study enrolled 17 female dogs: 10 with mammary tumors and seven controls without tumors. Blood samples were collected to measure miR-21, CEA, and CA 15-3, and histological samples were prepared for histological grading and immunohistochemistry.

Results

CA 15-3 was elevated in all animals, whereas CEA levels showed no change compared with controls. miR-21 was upregulated 12.84-fold in animals with CMT. The most frequently recorded CMT was the mixed type. Myoepithelial cells were identified by P63 immunoreactivity, but not SMA. High expression of miR-21 was observed with positive vimentin immunoreactivity, indicating the mesenchymal origin of the tumor cells.

Conclusion

The present study showed that miR-21 was elevated to a greater extent than CA 15-3 (12.84-fold vs. threefold). Tumors that was positive for vimentin immunoreactivity was also associated with an elevation in the levels of miR-21, showing that miR-21 is released from mesenchymal cells. These findings support the hypothesis that miR-21 may be a more sensitive, noninvasive indicator for CMT.

     

Expression of a tumor-associated antigen, RCAS1, in canine mammary tumors

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1), one of novel cancer cell-surface antigens, is strongly expressed in invasive cancers. RCAS1 inhibits the in vitro growth of lymphocytes such as T cells and natural killer (NK) cells, and induces apoptotic cell death. We investigated the expression of RCAS1 in canine mammary tumor cell lines and tumor cells by immunohistochemistry, and also in situ deoxyribonucleic acid (DNA) fragmentation in tumor-infiltrating lymphocytes (TILs) by the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. All canine mammary tumor cell lines expressed RCAS1 at both the messenger ribonucleic acid (mRNA) and protein level. Immunohistochemically, RCAS1 was negative in 100% of normal mammary glands, but was expressed in 100% of malignant tumors examined. In most malignant mammary tumors, RCAS1 was localized in the cytoplasm with no polarity of expression. In benign mammary tumors, it was detected on the luminal surface of the tumor cell. RCAS1 expression or localization was significantly correlated with malignancy. In situ DNA fragmentation of CD3-positive TILs was observed in RCAS1-expressing tumors. RCAS1-expressing tumors, indicating a possible induction of apoptotic cell death in TILs through RCAS1 expression. These observations suggest that RCAS1 probably plays an important role in tumor progression and escape from immune surveillance in canine mammary tumors.     

Plasticity of cloned canine mammary spindle cell tumor, osteosarcoma and carcinoma cells

Female dogs are frequently affected by mammary tumors, both carcinomas and sarcomas. The mechanisms behind mammary-tumor formation and the high degree of heterogeneity are not understood. To provide insight into this issue, it is important to determine the properties of the cells forming the different types of tumors. One question is if individual neoplastic cells can give rise to phenotypically distinct tumor types, i.e., show plasticity. We studied 3 different tumors (a spindle-cell tumor, an osteosarcoma, and a carcinoma) and followed the change of lineage marker expression between the primary canine mammary tumors, the clones derived from the corresponding tumors and in tumors generated after inoculation of tumor clones into nude mice (n = 75). Inoculation of clones derived from the spindle-cell tumor gave rise to spindle-cell tumors in nude mice. Several of these contained bone tissue, a sign of plasticity. Clones derived from the osteosarcoma were negative for a panel of lineage markers but, when inoculated into nude mice, they were able to form bone, again a sign of plasticity. In contrast to the primary carcinoma, most of the clones derived thereof lacked keratin expression, but keratin expression was recovered in most of the tumors formed after inoculation of clones into nude mice. Moreover, tumors generated from the carcinoma clones, in contrast to the primary tumor, were positive for smooth-muscle-cell markers. Our results point to plasticity in canine mammary tumors, as shown both by morphologic criteria and by expression patterns for lineage specific markers.     

Expression of the glutamine metabolism‐related proteins glutaminase 1 and glutamate dehydrogenase in canine mammary tumours

Glutamine metabolism is an important metabolic pathway for cancer cell survival, and there is a critical connection between tumour growth and glutamine metabolism. Because of their similarities, canine mammary carcinomas are useful for studying human breast cancer. Accordingly, we investigated the correlations between the expression of glutamine metabolism‐related proteins and the pathological features of canine mammary tumours. We performed immunohistochemical and western blot analysis of 39 mammary tumour tissues. In immunohistochemical analysis, the expression of glutaminase 1 (GLS1) in the epithelial region increased according to the histological grade (P < .005). In the stromal region, complex‐type tumours displayed significantly higher GLS1 intensity than simple‐type tumours. However, glutamate dehydrogenase expression did not show the same tendencies as GLS1. The western blot results were consistent with the immunohistochemical findings. These results suggest that the expression of GLS1 is correlates with clinicopathological factors in canine mammary tumours and shows a similar pattern to human breast cancer.     

实时荧光定量PCR对犬乳腺肿瘤组织TNFR1基因的定量检测

乳腺肿瘤是母犬中最为常见的肿瘤,运用实时荧光定量PCR检测了37例犬乳腺肿瘤病例和37份正常乳腺组织.结果表明:犬乳腺肿瘤组织中肿瘤坏死因子受体(TNFR1)的表达量显著低于正常对照组织(P<0.05).该试验结果说明,犬乳腺肿瘤的发生很可能与TNFR1表达降低有关,为深人研究肿瘤形成的分子机理提供了重要参考.     

Insulin receptor is expressed in normal canine mammary gland and benign adenomas but decreased in metastatic canine mammary carcinomas similar to human breast cancer

Insulin receptor (INSR) or insulin-like growth factor (IGF) signalling is speculated to be involved in mammary tumour development. Expression levels of members of the insulin receptor family (INSR, IGF1R, IGF2R, GHR) and their ligands IGF1and IGF2 were quantified in macro- and microdissected tissue samples of normal canine mammary gland, adenomas, carcinomas and their lymph node metastases to evaluate their potential impact on the carcinogenesis of canine mammary tumours. Normal mammary gland and adenomas had strong INSR expression, while carcinomas and metastases had significantly decreased expression. No differences were observed for IGF1R expression. IGF1, IGF2 and GHR mRNA expressions were strongly decreased in adenomas, carcinomas and metastases. INSR and IGF1R are therefore expressed in normal gland and adenomas and an increased stimulus by their ligands may be a proliferative stimulus in those tissues. However, decreased INSR expression carcinomas and their metastases render questionable its impact at late stages of carcinogenesis.     

Oncolytic reovirus synergizes with chemotherapeutic agents to promote cell death in canine mammary gland tumor

The oncolytic effects of reovirus in various cancers have been proven in many clinical trials in human medicine. Oncolytic virotherapy using reovirus for canine cancers is being developed in our laboratory. The objective of this study was to examine the synergistic anti-cancer effects of a combination of reovirus and low doses of various chemotherapeutic agents on mammary gland tumors (MGTs) in dogs. The first part of this study demonstrated the efficacy of reovirus in canine MGTs in vitro and in vivo. Reovirus alone exerted significant cell death by means of caspase-dependent apoptosis in canine MGT cell lines. A single injection of reovirus impeded growth of canine MGT tumors in xenografted mice, but was insufficient to induce complete tumor regression. The second part of this study highlighted the anti-tumor effects of reovirus in combination with low doses of paclitaxel, carboplatin, gemcitabine, or toceranib. Enhanced synergistic activity was observed in the MGT cell line treated concomitantly with reovirus and in all the chemotherapeutic agents except toceranib. In addition, combining reovirus with paclitaxel or gemcitabine at half dosage of half maximal inhibitory concentration (IC₅₀) enhanced cytotoxicity by activating caspase 3. Our data suggest that the combination of reovirus and low dose chemotherapeutic agents provides an attractive option in canine cancer therapy.     

犬乳腺肿瘤病理组织学观察及ER PR C-erbB-2的表达分析

通过对20例犬乳腺肿瘤进行病理组织学观察、免疫组织化学染色,探讨犬乳腺肿瘤病理形态学特点,ER、PR、Cerb B-2表达与乳腺肿瘤的关系。结果显示,20例犬乳腺肿瘤,70%为恶性肿瘤,其中良性肿瘤有导管内乳头状瘤和纤维性瘤,恶性肿瘤有浸润性导管癌,单纯癌,小叶原位癌,癌肉瘤,腺癌,恶性肿瘤发病率高于良性肿瘤。免疫组化结果显示-ER、PR在良性肿瘤的表达率均高于恶性肿瘤,P<0.05,差异显著;C-erb B-2在恶性肿瘤中的表达高于良性肿瘤,P<0.05,差异显著。提示,犬乳腺肿瘤恶性肿瘤发病率较高,ER、PR、C-erb B-2对犬乳腺肿瘤发病中的诊断、治疗及预后有重要意义。     

Potential markers for detection of circulating canine mammary tumor cells in the peripheral blood

Major discrepancies exist between histological predictions and actual metastatic potential of canine mammary tumors. Detection of circulating tumor cells (CTC) has a proven prognostic value for human breast cancer but similar markers for canine CTC are lacking. In the present study a panel of 16 human CTC markers was tested for their ability to specifically and sensitively detect canine carcinoma cells in peripheral blood. PCR assays for CK19, ERBB2, EGFR, CLDN7 and ELF3 were able to sensitively detect one carcinoma cell in up to 10(7) peripheral blood leukocytes. These CTC markers are thus candidate markers for identifying canine mammary CTC in the peripheral blood and may serve as prognostic factors for metastatic behavior in the future.     

犬乳腺肿瘤的诊治1例

犬乳腺肿瘤在母犬中非常常见,是仅次于皮肤肿瘤的最常见肿瘤,母犬的发生率约0.2%,大约50%的犬乳腺肿瘤是恶性的.犬后面几个乳腺发生肿瘤的可能性更大,因它们相对大一些,含的细胞略多一些,恶变的可能性也大一些.笔者近日诊断并治疗了一病例,现介绍如下:一.病史与临床检查(一)症状2010年9月21日,安徽省来安县一头12岁雌性(未绝育)京巴犬来我院就诊,体重6.3千克,主诉该犬两年多前左侧最后乳腺能摸到豌豆大硬块,但生长速度不快,最近半年硬块变大,速度较快,约一周前硬块表面皮肤破溃,一直不愈合,最近两天吃食不香.     

MUC1 expression in canine malignant mammary tumours and relationship to clinicopathological features

Mucin-1 (MUC1) is over-expressed in human breast carcinomas and is linked to a poorer prognosis. In this study, MUC1 expression in 32 spontaneous canine malignant mammary tumours was characterised in relation to histological type, mode of growth, grade, lymph node metastases and distant metastases. All tumours exhibited immunostaining for MUC1. In the normal canine mammary gland, MUC1 was expressed mainly in the apical cellular membrane, while in carcinomas MUC1 was detected in the cytoplasm only (56.3%) or in the cytoplasm with membrane accentuation (43.7%). There was a significant association between development of distant metastases and MUC1 over-expression (P=0.03), but no association with histological type, histological grade, mode of growth or lymph node metastasis.     

Alteration of somatostatin receptor 2 expression in canine mammary gland tumor

Somatostatin receptor 2 (SSTR2) is a negative regulator of cell proliferation in human breast cancer. Since there is little information about SSTR2 in canine mammary gland tumor (MGT), we clarified its distribution and expression level in normal mammary gland, benign MGT and malignant MGT. SSTR2 expression determined by immunohistochemical staining was observed in the cytoplasm of luminal epithelial cells. The intensity was negatively correlated with malignancy: normal tissues and some of the benign tumors had the highest levels, while the malignant tumors had little or no SSTR2 expression. As for the Western blotting, SSTR2 protein level in benign tumors was significantly lower than the normal mammary gland. On the other hand, SSTR2 protein levels in two of three malignant tumors were higher than the other groups. These results suggest that SSTR2 expression alters according to the malignancy of canine MGT.     

二甲双胍对犬乳腺肿瘤细胞周期及其相关蛋白的影响

为研究二甲双胍对犬乳腺肿瘤细胞增殖和细胞周期的影响,以犬乳腺肿瘤CHMm和CHMp为模型,采用终浓度为0、5、10、20、40mmol/L二甲双胍对其进行干预,应用CCK-8法检测细胞增殖活性,流式细胞仪检测细胞周期分布比例,再通过Western blot检测细胞周期相关蛋白cyclin D1和p27的表达情况。二甲双胍作用48 h后,与对照组比较,CHMm细胞试验各组的成活率显著降低(P0.05),而CHMp细胞除了5 mmol/L组(P0.05),其他试验各组的成活率也显著低于对照组(P0.05),并且均呈现一定的浓度依赖性。流式细胞仪分析细胞分布比例发现,CHMm的G0/G1期细胞比例从(38.7±5.89)%增加到(70.36±5.78)%,CHMp的G0/G1期细胞比例也从(37.03±4.23)%增加到(54.92±4.67)%。随着二甲双胍作用浓度的增加,CHMm和CHMp细胞内cyclin D1表达量呈现减少的趋势,而p27表达量呈现上升的趋势。研究结果表明,二甲双胍可以抑制犬乳腺肿瘤细胞体外增殖能力,诱导细胞发生G0/G1期阻滞,并下调cyclin D1和上调p27细胞周期相关蛋白表达量,从而为犬乳腺肿瘤治疗提供一定的理论基础。