人KB细胞和CCL227细胞与肿瘤球细胞超微结构的比较

目的:比较人口腔癌KB细胞和结肠癌CCL227细胞与肿瘤球细胞的超微结构,为肿瘤干细胞研究提供更多的资料.方法:使用有血清培养液培养两种肿瘤细胞,无血清培养液分别诱导两种肿瘤细胞生成肿瘤球.常规方法制备KB细胞、CCL227细胞、KB肿瘤球细胞、CCL227肿瘤球细胞透射电子显微镜切片,透射电子显微镜观察、拍照.结果:在四组样本中,细胞基本表现两种形态.一种细胞表面有突起,核糖体、线粒体数量相对较多.另一种细胞表面无突起,细胞核周围出现微丝,核糖体、线粒体数量减少,核内染色质出现靠边,后一种细胞在肿瘤球细胞中较多见.结论:伴随生理功能的改变,肿瘤干细胞的结构也发生了一些改变,这些改变可能会使蛋白合成下降.     

人KB细胞和CCL227细胞与肿瘤球细胞超微结构的比较

目的：比较人口腔癌KB细胞和结肠癌CCL227细胞与肿瘤球细胞的超微结构,为肿瘤干细胞研究提供更多的资料。方法：使用有血清培养液培养两种肿瘤细胞,无血清培养液分别诱导两种肿瘤细胞生成肿瘤球。常规方法制备KB细胞、CCL227细胞、KB肿瘤球细胞、CCL227肿瘤球细胞透射电子显微镜切片,透射电子显微镜观察、拍照。结果：在四组样本中,细胞基本表现两种形态。一种细胞表面有突起,核糖体、线粒体数量相对较多。另一种细胞表面无突起,细胞核周围出现微丝,核糖体、线粒体数量减少,核内染色质出现靠边,后一种细胞在肿瘤球细胞中较多见。结论：伴随生理功能的改变,肿瘤干细胞的结构也发生了一些改变,这些改变可能会使蛋白合成下降。     

Dietary fat and breast cancer metastasis by human tumor xenografts

Human breast cancer cell lines growing as xenografts in athymic nude mice have been used to examine the effects of dietary fat and fatty acids on tumor progression. The estrogen independent MDA-MB-435 cell line has the advantage that it metastasizes consistently to the lungs and forms quantifiable secondary nodules when injected into the mammary fat pads. With these breast cancer cells, the stimulating effects of polyunsaturated omega-6 fatty acids on both primary tumor growth and metastasis were demonstrated; in contrast, the long-chain omega-3 fatty acids were inhibitory. The model can also be adapted to examine dietary fatty acids, and inhibitors of their metabolism, as experimental adjuvant therapy after surgical excision of the primary tumors. Unfortunately, estrogen dependent human breast cancer cells do not metastasize, or do so rarely, in nude mice; in consequence, it is not possible to use the model to study estrogen-fatty acid interactions on the metastatic process. In addition to metastasis from a primary location, intravenous injection of MDA-MB-435 cells into the nude mouse host, particularly when combined with studies using Matrigel-based in vitro invasion assays, permits further dissection of the steps in the metastatic cascade which are influenced by dietary fatty acids. The results obtained by these several approaches have demonstrated distinct roles for the cyclooxygenase and lipoxygenase-mediated products of omega-6 fatty acid metabolism, and suggest new approaches to experimental breast cancer therapy.     

Inhibitory effect of endothelin A receptor blockade on tumor growth and liver metastasis of a human gastric cancer cell line

Background With metastatic progression, gastric cancer is incurable. Using a DNA microarray, we performed differential gene expression analysis of established highly metastatic gastric cancer cell lines and compared the findings with those from a low-metastatic parental cell line. The results demonstrated that the endothelin A receptor (ET-A) gene was the only one from the highly metastatic cell lines that was generally up-regulated. Methods To investigate the role that ET-A plays in gastric cancer metastasis, we studied the effect of an ET-A-selective antagonist, YM598, on cell proliferation, tumor growth, and liver metastasis of the highly liver metastatic cell line AZ-H5c, established from the low metastatic human gastric cancer cell line AZ-521. Results An in vivo study using nude mice demonstrated that YM598 had a significant growth inhibition effect on AZ-H5c at doses of 0.5–10.0 mg/kg. The liver metastatic rate was also significantly reduced by YM598: control, 83.3%; 1 mg/kg dosage, 16.7%; 10 mg/kg, 20%; and pretreatment at 1 mg/kg, 16.7%. There was no evidence of gross toxicity resulting from the YM598 treatment. Conclusion The ET-A blockade by YM598 had a strong inhibitory effect against tumor growth and liver metastasis of the gastric cancer cell lines. These data suggest that YM598 has potential as a novel therapeutic agent for inhibiting liver metastasis of gastric cancer.     

A novel matrix metalloproteinase inhibitor,FYK-1388 suppresses tumor growth,metastasis and angiogenesis by human fibrosarcoma cell line

The matrix metalloproteinases (MMPs) are likely to contribute to tumor cell invasion, metastasis and angiogenesis. Several MMP inhibitors have been developed, recently and their anti-tumor efficacy is being evaluated in clinical trials. FYK-1388 is a novel broad MMP inhibitor which blocks the activity of MMP-1, -2, -3, -7, -9, -13 and -14 (MT-MMP-1). It is especially effective against MMP-2 and -9 more so than other MMP inhibitors such as Marimastat, Ro 32-3555 and D-2163. Here, we investigated the anti-tumor efficacy of FYK-1388 using the human fibrosarcoma cell line HT-1080. These cells produced MMP-2 and -9, which FYK-1388 inhibited at a dose of 10(-8) M. FYK-1388 at 0.2 mg/mouse/day significantly suppressed tumor growth when given by s.c. injection for 22 days, experimental lung metastasis after 5 days s.c. injection and also suppressed tumor-induced angiogenesis in the dorsal air sac assay after 7 days s.c. injection. In the MTT assay, FYK-1388 had no effect on the in vitro growth of HT-1080 cells. These results suggest that FYK-1388 possesses anti-tumor efficacy as a result of inhibiting angiogenesis through the suppression of MMP-2 and -9 activity.     

Enhancement of angiogenesis, tumor growth, and metastasis by transfection of vascular endothelial growth factor into LoVo human colon cancer cell line.

The expression of vascular endothelial growth factor (VEGF), a highly potent angiogenic molecule, is thought to be correlated with the development of colon cancer; however, direct evidence for a role of VEGF in metastasis is lacking. This study was designed to more directly establish the role of VEGF in the growth and metastasis of human colon cancer using a genetically engineered cancer cell line. A stable VEGF gene-transfected human colon cancer cell line, LoVo, was made by genetic manipulation using eukaryotic expression constructs designed to express the complete VEGF121 cDNA in the sense orientation. Transfected clones were screened for VEGF121 mRNA expression by Northern blot analysis and for VEGF121 protein expression by Western blot analysis. Consequently, we obtained S17 cells that expressed a high level of both VEGF mRNA and VEGF protein. A vector-transfected clone (V7 cell) was used as a control. The experiment with the dorsal air sac method revealed that S17 cells elicited a stronger directional out-growth of capillaries than V7 cells. S17 cells formed faster-growing tumors than did V7 cells when xenografted s.c. into nude mice, although there was no significant difference in their in vitro proliferation. Tumors derived from S17 cells had more vascularity, as assessed by counting capillary vessels after staining with factor VIII, than did tumors derived from V7 cells (P < 0.05). With regard to the metastatic potential, S17 cells exhibited a higher capacity for both hepatic metastasis after the splenic portal inoculation and peritoneal dissemination after i.p. injection than did V7 cells. However, S17 cells showed no apparent metastasis, despite their rapid growth after orthotopic implantation. In conclusion, the present study showed clearly that VEGF plays an important role in cancer growth due to stimulation of angiogenesis by accelerating cell growth after reaching the target organs.     

Effect of troglitazone on tumor growth and pulmonary metastasis development of the mouse osteosarcoma cell line LM8

Background  

Osteosarcoma often develops micrometastases in the lung prior to diagnosis, causing a fatal outcome. Therefore, the prevention of pulmonary metastases is critical for the improvement of the prognosis of patients with osteosarcoma. The purpose of this study was to investigate whether troglitazone (TGZ) is considered as possible therapeutics in the treatment of growth and metastasis of osteosarcoma.     

TSU-68 (SU6668) inhibits local tumor growth and liver metastasis of human colon cancer xenografts via anti-angiogenesis

A number of receptor tyrosine kinases (RTKs) are involved in angiogenesis. TSU-68 (SU-6668) was developed as an inhibitor of RTKs involved in VEGF, bFGF and PDGF signaling, which then inhibits endothelial cell proliferation. We investigated the antitumor effects of TSU-68 against human colon cancer xenografts in male SCID mice and its anti-angiogenic activity using a dorsal air-sac (DAS) assay. TSU-68 was administered orally at a dose of 200 mg/kg twice daily. Mice bearing human colon carcinoma, HT-29, or WiDr xenografts were treated for 16 days. To determine the effect on hepatic metastasis, cell suspensions of HT-29 or WAV-I were injected into the spleen of mice on day 0, and mice treated for 28 days starting from day 1. For the DAS assay, HT-29, WiDr or WAV-I cells suspended in PBS at 2 x 10(7) cells/Millipore chamber were implanted subcutaneously into SCID mice, which were then treated from day 0 to 5, On day 6, the anti-angiogenic effects were assessed. Results indicated that TSU-68 significantly inhibited the growth of subcutaneous tumors. In the hepatic metastasis model, liver weights of the TSU-68-treated group were significantly reduced, compared to those of control mice. In the DAS assay, the angiogenic indices of the treated groups were significantly decreased for HT-29, WiDr and WAV-I tumors, with T/C ratios of 13.4, 50 and 35.3%, respectively. As TSU-68 significantly inhibited tumor growth and liver metastasis formation of human colon cancer xenografts, probably through anti-angiogenic activity, this agent may be useful for the treatment of colon cancer.     

DNA amplification and metastasis of the human melanoma cell line MeWo

A positive correlation was found between the presence of amplified DNA in the form of homogeneously staining regions (HSRs), and the formation of spontaneous metastases by the human melanoma cell line MeWo. HSR+ and HSR- MeWo sublines and clones were injected s.c. into BALB/c nude mice. All MeWo lines produced primary tumors that were allowed to grow to a similar size before the animals were sacrificed and examined for the presence of metastatic nodules in the lungs and abdominal cavity. HSR+ lines gave extensive metastases (greater than 100 nodules) in the lungs and/or liver and abdomen in 18 of 19 animals. The HSR- MeWo lines were effectively nonmetastatic, producing metastases in 3 of 20 animals, two of which had only a single metastatic lung nodule each. Evidence for the presence of HSRs in the primary tumors and metastatic nodules was obtained by DNA dot-blot hybridization to a sequence (D15Z1) amplified in the HSRs, flow cytofluorometry for cellular DNA content, and quinacrine staining of metaphase spreads. The HSR+ clones also colonized the lung to a much greater extent than HSR- clones following i.v. injection. In addition, the HSR+ clone had a selective advantage in lung colonization, since i.v. injection of a 50:50 mixture of HSR+ and HSR- clones resulted in extensive metastases populated exclusively by HSR+ cells. The results suggest that DNA sequences amplified in the HSRs of human melanoma MeWo cells may confer enhanced metastatic properties to these cells.     

Paris Saponin II suppresses the growth of human ovarian cancer xenografts via modulating VEGF-mediated angiogenesis and tumor cell migration

Purpose

Paris Saponin II (PSII) is an active component of Rhizoma Paridis—an essential ingredient in traditional Chinese herbal medicines. PSII can induce cytotoxic effects in cancer cells and inhibit ovarian cancer growth. Since pathological angiogenesis (henceforth, angiogenesis) is often associated with gynecological cancers, here, we investigated whether PSII renders effects on angiogenesis and examined possible molecular mechanisms underlying the effects of PSII.

Methods

The effects of PSII on the biofunctions of endothelial cells (EC), the crucial components of blood vessels, were examined by standardized angiogenesis in vitro and ex vivo assays, Western blot analysis, ELISA, and kinase assay. Angiogenesis in a xenograft mouse model of ovarian cancer was evaluated by color Doppler ultrasound and immunohistochemistry.

Results

PSII exerted marked inhibitory effect on the growth of VEGF-stimulated human umbilical vein endothelial cells in a dose–time-dependent manner, inhibited cell’s motility, and interfered with tubulogenesis. PSII also blocked microvessel outgrowth in a rat aortic ring assay and compromised angiogenesis in a mouse model of ovarian carcinoma using either SKOV3 or HOC-7 cell lines. VEGF levels in PSII-treated EC and tumor cells were reduced. In EC, PSII blocked the activation of VEGFR2 in dose-dependent manner leading to the reduction of VEGF-induced phosphorylation on several intracellular pro-angiogenic kinase, including the extracellular signal-related kinase, Src family kinase, focal adhesion kinase, and AKT kinase.

Conclusions

The results provided the first insight into the anti-angiogenesis properties of Saponin family in solid tumors and suggested a promising therapeutic potential of PSII in the ovarian cancer treatment.     

人口腔上皮样癌KB细胞系SP细胞及肿瘤球生长的研究

目的 :研究不同条件下口腔上皮样癌KB细胞及肿瘤球的生长特点.方法:用荧光染料Hoechst33342染色培养在有血清和无血清培养基中的KB细胞,用荧光显微镜观察SP细胞的形态.MTT法绘制KB细胞生长曲线.显微镜观察肿瘤球的生长.结果:用荧光显微镜在有血清和无血清培养基中均观察到KB细胞系中存在浅染和拒染的SP细胞,部分细胞出现偏染现象.酶标仪检测结果显示在有血清和无血清培养液培养的KB细胞,繁殖能力不同.在无血清培养液中可以培育出肿瘤球.结论:有血清和无血清培养液培养的KB细胞生长存在差异,肿瘤细胞可能存在不对称分裂,无血清培养液可培育出繁殖能力强的肿瘤球.     

Cadmium-induced inhibition of the growth and metastasis of human lung carcinoma xenografts: role of apoptosis

Our previous studies indicate that cadmium in mice can inhibitthe formation of chemically induced and spontaneously occurringtumors in the liver and lung. Cadmium is an effective anti-tumoragent when given at non-toxic doses and even when given wellafter tumor formation, implying a unique sensitivity in certaintumor cells. The present studies tested the ability of cadmiumto inhibit growth and progression of transplanted human pulmonarytumor xenografts. Male athymic nude mice were inoculated witheither H460 cells, originally derived from a non-small cellpulmonary carcinoma, or DMS 114 cells, originally derived froma small cell lung carcinoma, under the left renal capsule. Starting1 week later mice received 0, 125 or 250 p.p.m. cadmium in thedrinking water, levels without effect on host animal growthor survival, and were observed over the next 4 weeks (H460 cells)or 100 days (DMS 114 cells). An additional experiment gave cadmiumas an i.v. loading dose (20 µmol/kg) 4 days after renalinoculation with H460 cells and 200 p.p.m. cadmium in the drinkingwater from 7 days onward, with an observation period of 28 days.Cadmium caused dose-related reductions in the growth of tumorsresulting from the inoculation of either H460 or DMS 114 cellsof up to 83%. Additionally, cadmium reduced the rate of tumormetastasis to the lung by up to 58%. Cadmium treatment had noeffects on either Bcl-2 or Bax protein expression in tumor xenografts,indicating that apoptotic pathways probably do not contributeto this anti-neoplastic effect. These studies show cadmium caneffectively reduce growth and progression of human lung carcinomaxenografts in a fashion that is probably independent of apoptosis.     

塞来昔布抑制人类三阴性乳腺癌裸鼠移植瘤生长的实验研究

 【摘要】　目的　探讨塞来昔布（celecoxib）对人类三阴性乳腺癌（TNBC）肿瘤生长及细胞凋亡的影响。方法　32只裸鼠于背部皮下接种人类TNBC细胞株MDA-MB-231,随机分为空白对照组及低、中、高剂量塞来昔布组（25、50、100 mg?kg-1?d-1）。实验结束后,留取移植瘤标本,观察用药前后裸鼠肿瘤体积的变化;流式细胞术（FCM）检测肿瘤细胞凋亡率;免疫组织化学法检测NF-κB p65和p50分子的表达;Western blot法检测凋亡相关分子Caspase-3、Survivin蛋白的表达。结果　塞来昔布治疗组肿瘤体积较对照组均明显减小。中、高剂量塞来昔布治疗组凋亡率分别为（13.58±3.16）％、（21.91±4.75）％,与对照组的（3.15±1.73）％相比差异有统计学意义（t＝6.736,12.151,均P＜0.05）,塞来昔布低、中、高剂量组p65表达阳性率分别为79.3 %、46.7 %、23.9 %,与对照组（89.7 %）相比差异有统计学意义（χ2＝3.312,10.785,15.900,均P＜0.05）。Western blot结果显示,塞来昔布治疗后肿瘤组织中Caspase-3蛋白出现了裂解片段,并且随药物浓度增加,裂解片段表达量逐渐增加。Survivin蛋白随药物浓度增加表达逐渐下调。结论　塞来昔布可以诱导TNBC裸鼠移植瘤细胞凋亡,抑制肿瘤生长,其抗肿瘤作用机制可能部分与抑制p65分子以及下调Survivin蛋白表达有关。     

Inhibition of growth of subcutaneous xenografts and metastasis of human breast carcinoma by swainsonine: modulation of tumor cell HLA class I antigens and host immune effector mechanisms

Swainsonine, an indolizidine alkaloid, can decrease the organ colonization potential of metastatic murine tumor cells by augmentation of host immune effector mechanisms. In this report the above findings were extended by the demonstration that systemic administration of swainsonine strongly suppressed the growth of human breast carcinoma subcutaneous xenografts and experimentally induced lung metastases. This inhibition was not due to a direct effect of swainsonine on cell growth. However swainsonine treatment of tumor cells resulted in enhanced expression of HLA Class I antigens, and HLA class I mRNA. Swainsonine was a potent immunodulator as evidenced by the increased (a) cytotoxicity of splenocytes and macrophages, and, (b) proliferative potential of splenocytes and bone marrow cells. These data suggest that swainsonine-induced inhibition of tumor growth and metastases may be mediated via activation of host effector cells and/or alteration of tumor cell antigenicity.     

Heparanase and tumor invasion patterns in human oral squamous cell carcinoma xenografts

The role of heparanase, an endo-β-glucuronidase specifically degrading heparan sulfate (HS) glycosaminoglycans, in the mechanism of cancer cell invasion was investigated. Three human oral squamous cell carcinoma (SCC) cell lines (i.e., HSC-2, HSC-3 and LMF4), exhibiting various degrees of invasiveness to their surrounding tissues, were xenografted to the tongue of SCID mice in order to establish experimental cancer foci. Cancer cells and their surrounding tissues were examined for the expression of heparanase mRNA by an in situ hybridization technique, and for various basement membrane (BM)-associated molecules (i.e., perlecan, laminins and type IV collagen) by immunohistochemical procedures. BM structures surrounding cancer tissues were also examined by electron microscopy. Increasing levels of heparanase mRNA expression were observed with the progression of cancer invasiveness, as manifested by the destruction of BM structures. Enhanced heparanase enzyme activities in cancer tissues with more invasive properties were demonstrated by the disappearance of HS glycosaminoglycans in the face of retained HS pro-teoglycan core proteins. These results demonstrated a positive correlation between the heparanase enzyme activities and the invasiveness of human oral SCC. The roles of heparanase in cancer cell invasion were not precisely clarified by the present morphological study, but the enhanced heparanase activity in an early phase of BM destruction by cancer cells suggested the participation of this enzyme from the early phase of cancer invasion. (Cancer Sci 2003; 94: 277–285)     

Stimulation of tumor cell growth by vasoactive intestinal peptide

Vasoactive intestinal peptide (VIP) stimulated the growth of murine Lewis lung carcinoma cells in culture. The growth promoting effect was dependent on the concentration of VIP. Exposure to VIP for 12 hours followed by removal of the peptide resulted in sustained growth promotion for 4 to 5 days in culture. Synthetic fragments of VIP, i.e., VIP (1-16) and VIP (22-28), and the unrelated peptide neurotensin failed to stimulate the growth of the Lewis lung carcinoma cells. The growth-promoting effect of VIP was also observed in a murine mammary tumor cell line and a human lung adenocarcinoma cell line.     

Progesterone receptors A and B differentially affect the growth of estrogen-dependent human breast tumor xenografts

Sixty to seventy percent of all primary human breast cancers are estrogen-dependent and express both estrogen (ER) and progesterone receptors (PR). Whereas expression of the two naturally occurring PR isoforms, PR-A and PR-B, is close to equimolar in normal human tissues, the ratio of the two receptors varies extensively in tumors. This is important since the two PR are functionally distinct and have differential repressor effects on ER. The PR isoform content may, therefore, affect the outcome of endocrine therapies targeted at ER. Study of PR isoforms is difficult because the two receptors are co-expressed in cells under estradiol stimulation. We have engineered four sets of T47D human breast cancer cells that, independent of estrogen: (i) express only PR-A; (ii) express only PR-B; (iii) are PR-negative; or (iv) contain both PR isoforms. Each of these cell lines was grown into solid tumors in nude mice in a strictly 17-estradiol-dependent manner. Results show, first, that PR-A expressing cells grow into tumors that are approximately half the size of PR-B expressing tumors, and second, that the reduced growth of PR-A tumors occurs in the absence of PR ligand. Tamoxifen treatment preferentially inhibited the growth of PR-A tumors, whereas PR-B tumors were unaffected. Thus, PR are not just passive markers of functional ER; the prevalence of PR-A or PR-B may differentially influence tumor phenotype.