Increasing evidence suggests that cancer stem cells (CSCs) are responsible for tumor initiation and maintenance. Additionally, it is becoming apparent that cyclooxygenase (COX) signaling is associated with canine mammary tumor development. The goals of the present study were to investigate COX-2 expression patterns and their effect on CSC-mediated tumor initiation in primary canine mammary tissues and tumorsphere models using immunohistochemistry. Patterns of COX-2, CD44, octamer-binding transcription factor (Oct)-3/4, and epidermal growth factor receptor (EGFR) expression were examined in malignant mammary tumor (MMT) samples and analyzed in terms of clinicopathological characteristics. COX-2 and Oct-3/4 expression was higher in MMTs compared to other histological samples with heterogeneous patterns. In MMTs, COX-2 expression correlated with tumor malignancy features. Significant associations between COX-2, CD44, and EGFR were observed in low-differentiated MMTs. Comparative analysis showed that the levels of COX-2, CD44, and Oct-3/4 expression varied significantly among TSs of three histological grades. Enhanced COX-2 staining was consistently observed in TSs. Similar levels of staining intensity were found for CD44 and Oct-3/4, but EGFR expression was weak. Our findings indicate the potential role of COX-2 in CSC-mediated tumor initiation, and suggest that COX-2 inhibition may help treat canine mammary tumors by targeting CSCs.
Animals ; Antigens, CD44/genetics/metabolism ; Biomarkers, Tumor/genetics/metabolism ; Cell Transformation, Neoplastic/*genetics/metabolism ; Cyclooxygenase 2/*genetics/metabolism ; Dog Diseases/*genetics/metabolism ; Dogs ; Female ; Immunohistochemistry/veterinary ; Mammary Neoplasms, Animal/*genetics/metabolism ; Mammary Neoplasms, Experimental/*genetics/metabolism ; Neoplastic Stem Cells/*metabolism ; Octamer Transcription Factor-3/genetics/metabolism ; Receptor, Epidermal Growth Factor/genetics/metabolism ; Retrospective Studies

OBJECTIVETo study the effect of Runing II on expression of vascular endothelial growth factor (VEGF) in transplanted tumor of mammary cancer MA-891 in TA2 mice.

METHODSThe MA-981 mice mammary cancer cell cultivated in vivo was inoculated into the right axilla subcutaneously of TA2 mice to establish the transplanted tumor model, which were treated with Runing II.

RESULTSRuning II could inhibit the growth of transplanted tumor and the occurrence of lung metastasis (P < 0.05), reduce the expression of VEGF protein and mRNA in tumor tissue (P < 0.05).

CONCLUSIONRuning II could reduce the expression of VEGF protein and mRNA, hence to inhibit the growth of tumor and lung metastasis.

Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Female ; Mammary Neoplasms, Experimental ; metabolism ; Mice ; Neoplasm Transplantation ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A ; biosynthesis ; genetics

OBJECTIVETo establish a whole-body visualization model of breast cancer with high hepatic metastatic potential in nude mice and observe the development and metastasis of breast cancer by real-time imaging.

METHODSpEGFP-N1 plasmid was transfected into human breast cancer cell line MDA-MB-231 to obtain pEGFP-MDA-MB-231 cells that emitted fluorescence. pEGFP-MDA-MB-231 cells were inoculated orthotopically in BALB/C nude mice and cultured in vivo through serial passage, thereby establishing the mouse model bearing tumors with high hepatic metastasis potential. The fluorescence emitted from the tumors was quantitatively detected and imaged with a fluorescence stereo microscope for real-time visualization of the tumor growth and metastasis.

RESULTSThe transfected breast cancer cells stably and efficiently expressed EGFP. After inoculation of the transfected cells in nude mice, 20% of the first-generation cells showed hepatic metastasis, and the rate increased to 80% among the second-generation and up to 100% among the third-generation cells. The reliability of this visualization model was validated with conventional pathological methods.

CONCLUSIONThe whole-body visualization model bearing breast cancer with high hepatic metastasis potential provides a reliable means for studying the mechanisms of hepatic tumor metastasis, and can be instrumental in the exploration of novel means for breast cancer treatment.

Animals ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Disease Models, Animal ; Female ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Liver Neoplasms ; genetics ; metabolism ; secondary ; Mammary Neoplasms, Experimental ; genetics ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Microscopy, Fluorescence ; Neoplasm Transplantation ; Transplantation, Heterologous

OBJECTIVETo evaluate the feasibility of oral cytokine gene therapy against tumor using live attenuated Salmonella as a vector.

METHODSA live attenuated AraA- autotrophic mutant of Salmonella typhimurium (SL3261) was used as carrier for eukaryotic expression vectors EGFPN1 and pCMVmIL-12 administered orally in BALB/c and C57BL/6 mice. After 6 weeks, the mice were challenged with 4T1 or Lewis tumor cells, respectively, and flow cytometry and confocal microscopy were used to detect the expression of green fluorescence protein (GFP) in the tissues. PCR and ELISA were performed to detect the integration and expression of mIL-12 gene, and the survival time of the mice was also recorded.

RESULTSGFP expression and mIL-12 gene integration could be detected in the liver, spleen, intestinal, kidney and tumor tissues of the mice. The serum level of mIFN-gamma, mIL-12 increased significantly in mice with oral mIL-12 administration (P<0.05), which resulted in the survival prolongation of the mice as compared with the control mice (P<0.05).

CONCLUSIONOral gene therapy using live attenuated Salmonella can be potentially a simple, effective and above all, safe means for tumor treatment.

Administration, Oral ; Animals ; Carcinoma, Lewis Lung ; therapy ; Flow Cytometry ; Genetic Therapy ; methods ; Genetic Vectors ; administration & dosage ; genetics ; metabolism ; Green Fluorescent Proteins ; genetics ; metabolism ; Interleukin-12 ; genetics ; metabolism ; Mammary Neoplasms, Animal ; therapy ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Microscopy, Confocal ; Neoplasms, Experimental ; therapy ; Salmonella typhimurium ; genetics ; immunology ; metabolism ; Vaccines, Attenuated ; immunology

Tumor migration/invasion is the main cause of tumor progression and STAT3 is needed to enhance tumor migration/invasion by up-regulating MMP-9. Thus, agents that inhibit STAT3 activation may be used as an anticancer drug. We present herein that 6-methyl-2-propylimino-6, 7-dihydro-5H-benzo [1, 3]-oxathiol- 4-one (LYR71) , a derivative of trimeric resveratrol, has an anticancer activity through inhibition of STAT3 activation. We found that LYR71 suppressed STAT3 activation and inhibited the expression and activity of MMP-9 in RANTES-stimulated breast cancer cells. In addition, LYR71 reduced RANTES-induced MMP-9 transcripts by blocking STAT3 recruitment, dissociating p300 and deacetylating histone H3 and H4 on the MMP-9 promoter. Furthermore, LYR71 inhibited tumor migration/invasion in RANTES-treated breast cancer cells and consequently blocked tumor progression in tumor-bearing mice. Taken together, the results of this study suggest that LYR71 can be therapeutically useful due to the inhibition effect of STAT3-mediated MMP-9 expression in breast cancer cells.
Animals ; Antineoplastic Agents/chemistry/*pharmacology ; Bicyclo Compounds, Heterocyclic/chemistry/*pharmacology ; Blotting, Western ; Breast Neoplasms/genetics/metabolism/pathology ; Cell Line, Tumor ; Cell Movement/drug effects ; Cell Survival/drug effects ; Chromatin Immunoprecipitation ; Female ; Gene Expression/drug effects ; Humans ; Imines/chemistry/*pharmacology ; Immunohistochemistry ; Mammary Neoplasms, Experimental/pathology/prevention & control ; Matrix Metalloproteinase 9/genetics/*metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Molecular Structure ; Phosphorylation/drug effects ; Reverse Transcriptase Polymerase Chain Reaction ; STAT3 Transcription Factor/genetics/*metabolism ; Stilbenes/chemistry ; Xenograft Model Antitumor Assays/methods

OBJECTIVEThe chemopreventive activity and mechanism of dehydroepiandrosterone (DHEA) were studied.

METHODSModel of 7, 12-dimethylbenz (alpha) anthracene (DMBA) induced breast carcinoma in Sprague-Dawley rats, uitra-violet (UV)-induced DNA damage and Salmonella mutation assay were used.

RESULTSIn DMBA-induced rat mammary tumor model, the rats were orally given daily DHEA for 2 weeks before DMBA and continued for 10 weeks after DMBA administration. The results showed significant inhibition of tumor development by DHEA. The incidence of mammary carcinoma also decreased significantly on daily dose of oral 25 mg/kg DHEA with the mean tumor volume per rat also remarkably reduced by 92%. Moreover, 25 mg/kg DHEA treatment could significantly increase the carcinoma latency for about 3.5 weeks as compared with the control. Using polymerase chain reaction (PCR) assay, in vitro 10(-9) mol/L DHEA showed significant inhibitory effect on UV-induced DNA damage by 90%. In Ames test, DHEA was found to decrease DMBA and benzo (alpha) pyrene-induced TA98 and TA100 His(+) revertants markedly and the number of Salmonella clones were significantly reduced by 53.2% and 73.0% on dose of 5 microgram DHEA/plate. It was also shown that in vitro 10(-7) mol/L DHEA could also effectively inhibit the G-6-PDH activity, which might play an important role in its chemoprophylaxis activities.

CONCLUSIONThe results strongly prove that DHEA is a potent cancer chemoprophylaxis agent, which exhibits inhibitory potential on mutation and chemical carcinogen in vivo and in vitro.

9,10-Dimethyl-1,2-benzanthracene ; administration & dosage ; Adjuvants, Immunologic ; pharmacology ; Animals ; Antimutagenic Agents ; pharmacology ; DNA Damage ; drug effects ; Dehydroepiandrosterone ; pharmacology ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Glucosephosphate Dehydrogenase ; antagonists & inhibitors ; metabolism ; Mammary Neoplasms, Experimental ; chemically induced ; prevention & control ; Mutagenicity Tests ; Rats ; Rats, Sprague-Dawley ; Salmonella ; drug effects ; genetics ; Time Factors ; Tumor Cells, Cultured