裸小鼠人大肠癌淋巴道转移模型的建立

 目的建立一种人大肠癌简便、可行、稳定的淋巴道转移研究动物模型。方法裸鼠爪垫皮下注射人结肠癌HCT-116细胞,接种后在1~6周及8周不同时间段取材;收集腹股沟、腘窝,髂血管旁,肾门淋巴结以及肝肺脏器;进行HE染色及CEA免疫组化检测。观察种植瘤的成瘤率、生长情况以及淋巴结转移规律。结果爪垫种植1周后成瘤率100%。3周后淋巴结开始转移,到6周时第一级腹股沟腘窝淋巴结完全转移,转移率100%,其中腹股沟淋巴结转移阳性率76.9%(10/13);第二级髂血管旁淋巴结部分转移,转移率40%(2/5);未见第三级肾门淋巴结转移。到8周时见髂血管旁淋巴结转移率60%(3/5),肾门淋巴结开始转移(1/5),但均未见肝肺远处转移。HE染色及CEA免疫组化染色发现淋巴结有弥漫性癌细胞浸润。结论裸鼠爪垫皮下注射可成功建立人大肠癌淋巴道转移模型。此模型快速简便、转移集中、转移率高,可为研究结直肠癌淋巴道转移机制,药物干预等抗转移治疗提供理想的动物模型。     

Bone Metastasis in Advanced Breast Cancer: Analysis of Gene Expression Microarray

Background

Approximately 30% to 40% of breast cancer recurrences involve bone metastasis (BM). Certain genes have been linked to BM; however, none have been able to predict bone involvement. In this study, we analyzed gene expression profiles in advanced breast cancer patients to elucidate genes that can be used to predict BM.

Establishment of a Fluorescent Implantation Metastasis Model of Bladder Cancer and Real-time Microscopic Detection in Nude Mice

Objective: To establish a fluorescent implantation metastasis model of bladder carcinoma with high metastaticpotential in nude mice and observe development and metastasis. Methods: Human bladder cancer EJ cells withhigh invasive ability were screened and transfected with GFP plasmid to screen stable enhanced GFP-expressingclones instilled into the bladders of nude mice. Subsequent growth, invasion, and metastasis of the implantedtumors were observed and evaluated with a whole-body fluorescence optical imaging system. Results: Thetransfected bladder cancer EJ cells stably and efficiently expressed EGFP. The growth, invasion and metastasisof the implant bladder tumor were readily observed and accurately evaluated by fluorescent microscopy. Inthe bladders of nude mice, the rates of EGFP expression detected by flow cytometry at weeks 1-4 were 22.6%,46.7%, 62.3% and 72.7%, respectively, with clear increase over time. Conclusion: GFP-labeled bladder cancerEJ cells display green fluorescence under fluorescent microscopy and show stable GFP expression. The model willprovide a simple and reliable means for studying the mechanism of implantation metastasis of human bladdercancers in vivo.     

Core Needle Biopsy of Breast Cancer Tumors Increases Distant Metastases in a Mouse Model

INTRODUCTION: Incisional biopsies, including the diagnostic core needle biopsy (CNB), routinely performed before surgical excision of breast cancer tumors are hypothesized to increase the risk of metastatic disease. In this study, we experimentally determined whether CNB of breast cancer tumors results in increased distant metastases and examine important resultant changes in the primary tumor and tumor microenvironment associated with this outcome. METHOD: To evaluate the effect of CNB on metastasis development, we implanted murine mammary 4T1 tumor cells in BALB/c mice and performed CNB on palpable tumors in half the mice. Subsequently, emulating the human scenario, all mice underwent complete tumor excision and were allowed to recover, with attendant metastasis development. Tumor growth, lung metastasis, circulating tumor cell (CTC) levels, variation in gene expression, composition of the tumor microenvironment, and changes in immunologic markers were compared in biopsied and non-biopsied mice. RESULTS: Mice with biopsied tumors developed significantly more lung metastases compared to non-biopsied mice. Tumors from biopsied mice contained a higher frequency of myeloid-derived suppressor cells (MDSCs) accompanied by reduced CD4 + T cells, CD8 + T cells, and macrophages, suggesting biopsy-mediated development of an increasingly immunosuppressive tumor microenvironment. We also observed a CNB-dependent up-regulation in the expression of SOX4, Ezh2, and other key epithelial-mesenchymal transition (EMT) genes, as well as increased CTC levels among the biopsy group. CONCLUSION: CNB creates an immunosuppressive tumor microenvironment, increases EMT, and facilitates release of CTCs, all of which likely contribute to the observed increase in development of distant metastases.Abbreviations: CCAC, Canadian Council on Animal Care; CNB, core needle biopsy; CTCs, circulating tumor cells; EMT, epithelial-mesenchymal transition; H&E, hematoxylin and eosin; MDSCs, myeloid-derived suppressor cells; PGE2, prostaglandin E2     

Frequent Development of Murine T-Cell Lymphomas with TcRα/β+, CD4-/8 Phenotype after Implantation of Human Inflammatory Breast Cancer Cells in BALB/c Nude Mice

Tumors developed quite frequently in some of the visceral organs, including spleen and liver, in BALB/c nude mice upon subcutaneously xenografting surgical specimens from five different inflammatory breast cancer patients. All of these tumors developed within two and a half months to one year after the subcutaneous inoculation of surgical specimens. From these tumors, five independent transplantable tumors, including tMK-2, tHK-1, tYK-1, tYK-2 and tTY-1 have been established. Chromosome analysis, morphologic studies by light and electron microscopy and phenotype analysis indicated that these tumors are of mouse origin. The tMK-2 tumor was highly metastatic to the spleen and liver when it was subcutaneously transplanted into the right scapular region. In addition, the region where the tMK-2 tumor cells were subcutaneously inoculated showed an apparently inflammatory process represented by erythema. After subcutaneous inoculation into the right scapular region, tHK-1, tYK-1,2, and tTY-1 tumors also metastasized to some of the visceral organs, including spleen and liver. From these tumors, in vitro cell lines were established. The cells grew in a stromal-cell dependent manner under in vitro culture conditions. The cells were again tumorigenic at the inoculated region and metastasized to various organs, including liver and spleen, of BALB/c nude mice. Histological examination revealed that the tumors showed features of malignant lymphoma. Phenotypically, these five tumors expressed early T lymphocyte markers as revealed by anti-mouse anti-TcR4aL/β, anti-CD3, CD4 and CDS monoclonal antibodies. To our knowledge, these cell lines are the first T-cell lines showing the phenotype of extrathymically differentiated T-cells in the liver.     

Inhibitory Effects of Ginsenoside Rh2 on Tumor Growth in Nude Mice Bearing Human Ovarian Cancer Cells

Ginsenoside Rh₂ (Rh₂), isolated from an ethanol extract of the processed root of Panax ginseng CA Meyer, inhibits the growth of B16 melanoma cells. This study was designed to evaluate the ability of Rh₂ to inhibit growth of human ovarian cancer cells (HRA) in vitro and in nude mouse. Rh₂ inhibited proliferations of various established human ovarian cancer cell lines in a dose-dependent manner between 10 and 60 μM in vitro and induced apoptosis at around the IC₅₀ dose. When HRA cells were inoculated s.c. into the right flank of nude mice, all mice formed a palpable tumor within 14 days. Although i.p. administration of Rh₂ alone hardly inhibited the tumor growth, when Rh₂ was combined with cis-diamminedichloroplatinum(II) (CDDP) the tumor growth was significantly inhibited, compared to treatment with CDDP alone. When mice were treated p.o. with Rh₂ daily (but not weekly), the tumor growth was significantly (P<0.01) inhibited, compared to CDDP treatment alone. When Rh₂ was combined with CDDP, the degree of tumor growth retardation was not potentiated. The survival time was significantly (P<, we examined whether p.o. administration of Rh₂ has a dose-dependent inhibitory effect on the tumor growth. I.p. and weekly administration of CDDP had more potent antitumor activity in the order of 1 mg/kg, 2 mg/kg and 4 mg/kg, whereas p.o. and daily administration of Rh₂ (0.4 to 1.6 mg/kg) not only had antitumor activity comparable to that of 4 mg/kg CDDP, but also resulted in a significant increase of the survival. Doses of Rh₂ used in this study did not result in any adverse side-effects as confirmed by monitoring hematocrit values and body weight, unlike 4 mg/kg CDDP, which had severe side-effects. It is noteworthy that p.o. but not i.p. treatment with Rh₂ resulted in induction of apoptotic cells in the tumor in addition to augmentation of the natural killer activity in spleen cells from tumor-bearing nude mice. Thus, particularly in view of the toxicity of CDDP, Rh₂ alone would seem to warrant further evaluation for treatment of recurrent or refractory ovarian tumor.     

Targeting Mutant p53 by a SIRT1 Activator YK-3-237 Inhibits the Proliferation of Triple-Negative Breast Cancer Cells

Many types of mutations in tumor suppressor p53 are oncogenic through gain-of-function. Therefore, targeting mutant p53 (mtp53) is a promising therapeutic approach to fight against many types of cancers. We report here a small molecule compound YK-3-237 that reduces acetylation of mtp53 and exhibits anti-proliferative effects toward triple-negative breast cancer (TNBC) cells carrying mtp53. YK-3-237 activates SIRT1 enzyme activities in vitro and deacetylation of both mtp53 and wild type p53 (WTp53) in a SIRT1-dependent manner. Deacetylation of mtp53 resulted in depletion of mtp53 protein level and up-regulated the expression of WTp53-target genes, PUMA and NOXA. YK-3-237 also induces PARP-dependent apoptotic cell death and arrests the cell cycle at G2/M phase in mtp53 TNBC cells. Taken together, our data suggest that targeting acetylation of mtp53 is a potential target to treat human cancers.