ED-110, a Novel Indolocarbazole, Prevents the Growth of Experimental Tumors in Mice

A new indolocarbazole compound, ED-110, which was obtained by glucosylating a microbial product (BE-13793C) and is a potent topoisomerase I inhibitor, showed characteristic inhibitory effects on the growth of 12 human tumor cell lines tested. The IC₅₀ values of ED-110 against 9 of the 12 lines ranged from 11.5 μg/ml to 0.07 μ g /ml, while the remaining 3 lines were quite resistant (IC₅₀, >100μg/ml). In in vivo experiments, i.p. treatment with ED-110 increased the survival period by more than two-fold in mice implanted i.p. with P388, L1210, L5178Y or EL4 murine leukemic cells. The minimum effective dose increasing the life-span of mice bearing P388 leukemia by 25% was <2.5 mg/kg/day × 10 and the maximum tolerated dose was > 160 mg/kg/day × 10. ED-110 was also effective against the spontaneous metastasis of mouse Meth A fibrosarcoma cells and the growth of xenografted MKN- 45 human stomach cancer cells as well as s.c. implanted mouse colon 26 and IMC carcinoma cells. These results indicated that ED-110 may have potential as a new antineoplastic agent with a large chemotherapeutic index and a wide range of effective doses.     

Antimetastatic Effect of a Novel Indolocarbazole (NB-506) on IMC-HM Murine Tumor Cells Metastasized to the Liver

IMC-HM cells were isolated from spontaneously induced ascitic IMC carcinoma cells that had been maintained intraperitoneally in CDF₁ mice. Metastasis to the liver of subcutaneously implanted IMC-HM cells was detected 10 days after implantation into the flanks of mice (day 10), but metastasis to other organs was limited. Thereafter, however, tumor cells spread rapidly to lymph nodes, lung, spleen, ovary and other organs, and the mice died on day 13 to 18. We report here, together with the properties of IMC-HM cells, the effects of adriamycin, cisplatin, etoposide and a new indolocarbazole antitumor compound (NB-506) on this model of metastasis. Although these anticancer agents all inhibited the growth of the subcutaneous tumors, their effects on the life span of the tumor-bearing mice varied. Treatment with NB-506, started on day 1, more than doubled the survival period at doses 30 mg/m² to 900 mg/m². Further, treatment with NB-506, started on day 4 after resection of the primary tumor, inhibited growth of the metastasized tumor in the liver and other organs. Etoposide also increased the life span at a limited range of doses. However, the life-prolonging effects of adriamycin and cisplatin were marginal. These results demonstrate that IMC-HM carcinoma is a good model for spontaneous metastasis to the liver followed by lethal spread to many organs. Moreover, NB-506 was found to be highly effective against the growth not only of subcutaneous tumors, but also of tumors metastasized to the liver.     

A phase I study of the safety and pharmacokinetics of edotecarin (J-107088), a novel topoisomerase I inhibitor, in patients with advanced solid tumors

Purpose To assess the maximum tolerated dose, safety, and pharmacokinetic (PK) profile of escalating doses of the novel topoisomerase I (topo I) inhibitor edotecarin (J-107088) given as a 2-h intravenous (IV) infusion once every 21 days in patients with advanced solid tumors who had not responded to standard therapy. Patients and methods Twenty-nine patients (18M:11F) received a 2-h IV infusion of edotecarin in doses of 6, 8, 11, 13, or 15 mg/m² every 21 days (with an additional 1–2 weeks permitted for recovery) and were evaluated for safety, PK, and tumor response. Results The most common non-hematologic toxicities were grade 1–2 nausea, fatigue, anorexia, vomiting, and fever. The most common hematologic toxicities were grade 1–2 thrombocytopenia and grade 3–4 neutropenia, leukopenia, and anemia. No grade 3–4 diarrhea was reported. Dose-limiting toxicities were observed in four patients at the 15 mg/m² dose and one patient at the 13 mg/m² dose. These toxicities included grade 3 nausea, vomiting, headache, and fatigue, as well as grade 4 neutropenia and febrile neutropenia. The maximum tolerated dose was declared at 15 mg/m². One patient with bladder cancer had a confirmed partial response at a dose of 13 mg/m². There was a trend to dose-proportional increases in edotecarin peak plasma concentrations and area under the curve values. Renal excretion of edotecarin was minimal (3–8% of the dose). Conclusion The recommended Phase II dose of edotecarin is 13 mg/m² once every 21 days. The toxicities in this study were those typical of cytotoxic chemotherapy and less severe than those associated with other topo I inhibitors. The observed safety profile and preliminary evidence of clinical benefit warrant further investigation of this drug as monotherapy or part of combination therapy in patients with solid tumors.Presented at the American Society of Clinical Oncology 2000 Annual Meeting, abstract #767.     

In vivo anti-tumor activity of a novel indolocarbazole compound, J-107088, on murine and human tumors transplanted into mice.

J-107088 (6-N-(1-hydroxymethyl-2-hydroxy)ethylamino-12,13-dihydro-2,10-dihydroxy- 13-(beta-D-glucopyranosyl)-5H-indolo[2,3-a]-pyrrolo [3,4-c]carbazole-5,7(6H)-dione) is a derivative of NB-506, an indolocarbazole compound previously reported as an anti-tumor agent targeting topoisomerase I. The optimal administration schedule of J-107088 was found to be intermittent injections. The GID75 (75% growth inhibiting total dose) values of J-107088 against LX-1 lung cancer and PC-3 prostate cancer when given by intermittent injection (twice a week for 2 consecutive weeks) were 200 and 15 mg/m2, respectively, whereas the 10% lethal dose (LD10) values of J-107088 against LX-1- and PC-3-bearing mice were 578 and 1200 mg/m2. The ratio of LD10/GID75 indicates the therapeutic window of an anti-tumor agent. Although the ratios of doxorubicin, paclitaxel and cisplatin against PC-3 were <0.3, <0.5 and <0.2, J-107088 showed the widest therapeutic window among the anti-tumor drugs tested. J-107088 was also effective on cells that had acquired resistance related to P-glycoprotein. Furthermore, J-107088 was found to be highly effective in inhibiting proliferation of micro-metastases of tumors to the liver in mice. Therefore, J-107088 is considered to be a promising candidate as an anti-tumor drug for treatment of solid tumors in humans.     

Anti-tumor Activities of Novel Estrogen Compound 17aα-D-Homo-Ethynylestradiol-3-Acetate

Objective:To study the anti-tumor activities of novel estrogen compound 17a α-D-homo-ethvnvlestradiol-3-acetate in vitro and in vivo. Methods:In vitro anti-tumor activity was assayed in adenoma cells A549 and human liver cancer cells Bel-7402 using MTT method,and half-inhibitory concentration (IC50)were observed. In vivo the pulmonary adenoma LA795 cells was selected and the conventional assay method of anti-tumor activity was employed.5,7.5,10 mg/kg of 17a α-D-homo-ethynylestradiol-3-acetate was administered by i.P., and tumor-inhibitory rate, thymus and spleen indexes,bone marrow cells(BMC)were observed. Results:IC50 of 17a α-D-homo-ethynylestradiol-3-acetate in vitro for A549 and Bel-7402 cells were 12.28 μg/ml and 17.79 μg/ml, respectively.In vivo the highest tumor-inhibitory rates for LA795 was 60.0%(P＜0.01).The drug had hardly any side-effect in spleen indexes,thymus indexes,and BMC compared with control mice. Nevertheless,compared with the positive control drug cyclophosphamide(CY),thymus and spleen indexes,BMC showed obvious diffefences(P＜0.01). Conclusion:17a α-D-homo-ethynylestradiol-3-acetate has obvious anti-tumor activities in vitro and in vivo with low side-effect, thus worth further investigation.     

低磁场核磁共振对小鼠原发性和移植性肿瘤的成像效果

目的 利用小鼠原发性和移植性肿瘤模型检测0.5T低磁场小动物核磁共振（MRI）的成像效果。方法 采用0.5T低磁场MRI仪对小鼠皮下移植瘤（HepG2、S180、H-ras12V转基因小鼠肝肿瘤组织）和原发性肝肿瘤（H-ras12V转基因肝癌小鼠）进行检测,观察其影像学表现并对H-ras12V转基因小鼠原发性肝肿瘤进行病理学确认。结果 皮下移植瘤小鼠（S180、HepG2、H-ras12V转基因小鼠肝肿瘤组织）的肿瘤生长状态良好,肉眼及X光检测均可观察到显著的肿瘤团块。MRI成像结果表明,皮下肿瘤部位的T1WI上表现为低信号、T2WI上表现为高信号、成像清晰、效果良好,且三种小鼠皮下移植瘤的MRI成像效果相似。对于H-ras12V转基因小鼠原发性肝肿瘤的MRI成像结果表明,在转基因小鼠的肝区出现了T1WI上表现为低信号的多个区域,这些相应区域在T2WI上表现为高信号。病理解剖及病理切片证实,这些区域为多发性肝肿瘤。结论 利用低磁场MRI可以对小鼠原发性肝肿瘤和移植性肿瘤进行有效的检测,可作为小鼠肿瘤无创检测的有效方法。     

A Novel Combretastatin A-4 Derivative, AC-7700, Shows Marked Antitumor Activity against Advanced Solid Tumors and Orthotopically Transplanted Tumors

AC-7700, a novel combretastatin A-4 derivative, suppresses the growth of solid tumors by inhibiting tumor perfusion. We evaluated the antitumor activity of AC-7700 on solid tumors in two experimental models, an advanced tumor model (murine colon 26 (c26) adenocarcinoma, colon 38 (c38) adenocarcinoma, MethA fibrosarcoma, Sarcoma 180 (S180), Lewis lung carcinoma (3LL), human LS180 adenocarcinoma) and an orthotopically transplanted tumor model (c26), compared with that of cisplatin (CDDP). The maximum tolerable dose (MTD) of CDDP suppressed early-stage c26 and c38 tumor growth when treatment was started after the tumor volume (TV) reached 0.2–0.5 cm³, but it showed reduced activity against the same tumors at an advanced growth stage when TV exceeded 2 cm³. At its MTD, AC-7700 was active against all tumors tested except 3LL in both early and advanced growth stages, reducing the tumor mass and having a curative effect in advanced c38 tumors. AC-7700 was also effective on orthotopically transplanted c26 tumors, showing a comparable activity to that on subcutaneous tumors. Unlike flavon acetic acid, which damages tumor vasculature by inducing endogenous tumor necrosis factor-α production, AC-7700 potently suppressed the growth of advanced c26 tumors in athymic as well as euthymic mice. These results suggest that AC-7700 is a novel antivascular agent that may have potent activity against advanced-stage cancer in the clinical setting.     

Antitumor Activity of ME2303, a Fluorine-containing Anthracycline, against Human Tumors Implanted in Nude Mice

A fluorine-containing anthracyctine, ME2303, given intravenously once a week for 4 weeks at the maximum tolerated dose showed better therapeutic effects against 2 gastric, 3 lung and 2 human breast tumor xenografts than did adriamycin (ADM) at the maximum tolerated dose. Among the tumors, ME2303 showed a better effect against St-40, a well-differentiated human gastric adenocarcinoma, against which ADM showed only a marginal effect. Likewise, ME2303 was more effective against Lu-24 human small cell carcinoma and MX-1 human medullary tubular adenocarcinoma than ADM. Notably, the Lu-24 tumor, developed in nude mice, disappeared after the treatment in 3 out of 6 mice. ME2303 would be an interesting compound for phase I and II clinical studies in the future     

Antitumor Activity and Pharmacokinetics of a Morpholino-anthracycline Derivative (KRN8602) against Human Breast Carcinoma Xenografts Serially Transplanted into Nude Mice

The antitumor activity and pharmacokinetics of (7 R , 8 S , 10 S )-10-((3-deamino-3-(4-morpholino)-2,3,6-trideoxy-α- l - lyxo -hexopyranosyl)oxy)-8-ethyl-7,8,9,10-tetrahydro-1,6,7,8,11-pentahydroxy-5,12-naphthacenedione hydrochloride (KRN8602) were evaluated using five human breast carcinoma xenografts in nude mice. The maximum non-toxic dose of KRN8602 was 2 mg/kg by q4d×3 intraperitoneal and peroral administration. KRN8602 showed significant antitumor activity against MX-1, which is less sensitive to adriamycin, with the chemotherapeutic indices of 13.0 for po administration and 9.5 for ip injection. Although KRN8602 also inhibited the growth of T-61 significantly, the antitumor activity of this agent against the other three breast carcinoma xenografts was limited. To elucidate this discrepancy, pharmacokinetic analysis and MTT assay were conducted using the KRN8602-sensitive MX-1 and KRN8602-insensitive R-27. While no differences were observed in the area under the curve and the peak concentration of KRN8602 for each tumor, a difference in the sensitivity of the tumor strains was obvious in MTT assay. The efficacy of this agent seemed to depend on the sensitivity of each type of tumor cell rather than the concentration of agent in tumor tissues. If it were possible to select patients with sensitive tumor cells to this agent by the MTT assay, the phase II trial might be completed within a short period by reducing the number of studied patients.     

In vitro and In vivo Antitumor Activity of Tiliacorinine in Human Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a fatal cancer with poor prognosis and less than 10% of CCA patients can be offered surgical cure. Conventional chemotherapy results in unfavorable outcomes. At present, plant-derived compounds are gaining interest as potential cancer therapeutics, particularly for treatment-refractory cancers. In this study, antitumor activity of tiliacorinine, the major alkaloid isolated from a tropical plant, on CCA was first demonstrated. Antiproliferative effects of tiliacorinine on human CCA cell lines were investigated using SRB assays. Acridine orange/ethidium bromide staining, flow cytometric analysis and DNA laddering assays were used for apoptotic determination. Apoptosis-related proteins were verified by Western blotting and antitumor activity of tiliacorinine in vivo was demonstrated in CCA xenografted mice. Tiliacorinine significantly inhibited proliferation of human CCA cell lines with IC50 4.5-7 μM by inducing apoptosis through caspase activation, upregulation of BAX, and down-regulation of BclxL and XIAP. Tiliacorinine considerably reduced tumor growth in CCA xenografted mice. These results demonstrated antitumor effects of tiliacorinine on human CCA in vitro and in vivo. Tiliacorinine may be an effective agent for CCA treatment.     

Rapid Growth and Spontaneous Metastasis of Human Germinal Tumors Ectopically Transplanted into Scid (Severe Combined Immunodeficiency) and Scid-nudestreaker Mice

Xenograft acceptance, growth and spontaneous metastasis of ectopically transplanted human germinal tumors were compared among scid mice, athymic nude mice and F₂ hybrids constructed from scid and nude mice, in relation to the impairments of T and B cell functions in these mice. In scid mice which are deficient in T and B cell functions, human yolk sac tumor (YST-2) that originated from the ovary grew to enormous sizes in 100% of the animals after both subcutaneous and intraperitoneal transplantation, while only half (59.1% and 51.9%) of the subcutaneous and none of the intraperitoneal transplants were accepted in usual athymic nude mice (BALB/c- nu/nu and CDl- nu/nu ). The YST-2 grew rapidly in scid mice, developing 3 to 10 times larger tumors compared to nude-streaker (AKR/J- nu^str/nu^str ) and usual nude mice, respectively. Furthermore, ectopically transplanted tumors spontaneously metastasized to distant organs (mostly to the lung) in scid mice (but less frequently in leaky scid mice), while metastases have never been found in nude mice. Although a xenograft of human classic (typical or pure) seminoma of the testis has never been established in nude mice, it grows slowly in one-third (36.4%) of scid mice and very rapidly in all of scid-nu ( scid/scid; nu^str/nu^str ) double mutant mice. Spontaneous metastases of xenografted seminomas were also observed in distant organs (lymph node, lung, liver, spleen, and kidney). The metastastic distribution of the two human germinal tumors in scid and scid- nu^str mice mimics that found in human. These results (xenograft acceptance, growth of transplanted tumors and degree of metastatic spread) were compatible with the level of T and B cell impairments indicated by FACS analysis, as well as mitogen responses, serum IgG and morphological features of the thymus.     

Anti-Metastatic Potential of a Novel Xanthone Sourced by Swertia chirata Against In Vivo and In Vitro Breast Adenocarcinoma Frameworks

Background: The Anticancer property of Swertia chirata has been well established. It forms a rich source of compounds to which its anticancer property can be attributed, among the compounds found in S. chirata xanthones form an important group. Among the most abundant xanthones found in S. chirata, 1,5,8-trihydroxy-3-methoxy xanthone (TMX) was found to be most effective. As metastasis is the underlying cause of most cancer-related deaths, in this study, we evaluated the anti-metastatic potential of TMX against adenocarcinoma both in vivo and in vitro. Materials and Methods: In vivo anti-metastatic potential was proved by histological evidence of different organs, giemsa staining of bone marrow, subcutaneous re-injection of the aberrant bone marrow cells into the right flank of the mice to observe the formation of tumors and analyzing the markers related to metastasis by immunohistochemistry (IHC) and western blot. In vitro validation of anti-metastatic potential was carried out against human breast adenocarcinoma cell line MCF-7 by primarily analyzing the migratory property of cells through scratch wound healing assay and the ability of cells to form colonies. The re-validation part was performed by western blot of markers related to metastasis and real-time analysis of EMT related markers. Results: In vivo, TMX treatment restricted metastasis of EAC induced solid tumor to liver, lung, bone marrow, and validation of this finding was achieved by down regulation of metastatic and EMT markers.  In vitro, TMX treatment restricted migratory and colony forming ability of MCF-7 cells by down regulating metastatic and EMT markers. Conclusion: It was proved from our study that TMX treatment successfully reduced the metastatic potential of EAC induced solid tumor, with in vitro validation TMX on the MCF-7 cell line.     

FK317, a Novel Substituted Dihydrobenzoxazine, Exhibits Potent Antitumor Activity against Human Tumor Xenografts in Nude Mice

The antitumor effects of FK317, a novel substituted dihydrobenzoxazine, were evaluated using human tumor xenografts (small cell lung cancer, non-small cell lung cancer, stomach cancer, colon cancer, pancreatic cancer, breast cancer, cervical cancer and ovarian cancer). Tumor growth-inhibitory effects and the effective dose-range of FK317 were much stronger and broader, respectively, than those of reference drugs such as mitomycin C, adriamycin, cisplatin, taxol and irinotecan. Furthermore, the body weight decrease and myelosuppression in FK317-treated mice were less than in the animals given any of the reference drugs. To explain this tumor selectivity, the distribution of FK317 was investigated after dosing tumor-bearing mice with the ¹⁴C-labelled compound. The concentration of FK317 in tumor tissues was relatively low, and long tumor retention was not observed. However, thin-layer chromatographic separation revealed that the radioactivity in the tumor resided mainly in strongly cytotoxic metabolites, while that in other tissues resided mainly in non-cytotoxic metabolites. These results suggest that FK317 shows strong antitumor activity without side effects, and one reason for this is its specific metabolite pattern. FK317 is now undergoing phase I clinical trials.     

In vivo Antitumor Activity of Hexamethylmelamine against Human Breast, Stomach and Colon Carcinoma Xenografts

We have evaluated the antitumor activity of Altretamine (hexamethylmelamine, HMM) on human carcinoma xenografts serially transplanted in nude mice. Five human breast carcinoma xenografts, MX-1, T-61, MCF-7, R-27 and Br-10, were inoculated subcutaneously into female nude mice. Two human stomach carcinoma xenografts, SC-1-NU and St-4, and three human colon carcinoma xenografts, Co-3, Co-4 and Co-6, were inoculated subcutaneously into male nude mice. One pellet of 17β-estradiol (0.1 mg/mouse) was inoculated subcutaneously in the mice transplanted with MCF-7 when the tumors were inoculated. HMM was administered per os daily for 4 weeks. MX-1 and T-61 tumors regressed completely after treatment with HMM at a dose of 75 mg/kg (the maximum tolerated dose: MTD) for MX-1 and 25 mg/kg for T-61. Br-10 was sensitive, whereas MCF-7 and R-27 were resistant to HMM at its MTD. HMM exerted the most potent antitumor effect against T-61. Against MX-1, it exerted an antitumor effect equivalent to that of cisplatin or cyclophosphamide. In addition, this agent was effective against all stomach and colon carcinoma xenografts, in particular St-4 (T/C%= 10.7: the mean tumor weight of treated group/the mean tumor weight of control group) and Co-3 (T/C%=31.5%) which are insensitive to presently available agents. HMM seems worthy of further clinical investigation as a candidate agent to treat breast, stomach, colon and other carcinomas.     

Cell-killing Activity and Kinetic Analysis of a Novel Antitumor Compound NC-190, a Benzo[a]phenazine Derivative

A novel antitumor compound, N-β-dimethylaminoethyl 9-carboxy-5-hydroxy-10-methoxybenzo[a]-phenazine-6-carboxamide sodium salt (NC-190), was evaluated for antitumor activity in vitro against cultured tumor cell lines, and the kinetics of cell killing was elucidated. NC-190 strongly inhibited the growth of all of 3 murine tumor cell lines, 7 human tumor cell lines and 2 normal cell lines. With continuous exposure, the 50% inhibition concentrations were in the range of 0.005–0.06 μg/ml, except for KATO-III (2.15 μ g/ml). By colony-forming assay, concentrations of NC-190 giving 90% cell kill (IC₉₀) at various exposure times were obtained with HeLa S3 cells. The plot of IC₉₀exposure time on a log-log scale was linear for NC-190 with a slope of -1, which is typical for cell cycle phase-nonspecific agents. A 2 h treatment with NC-190 induced a rapid reduction in cell viability at doses of more than 3 μ g/ml. At the dose where colony formation was completely inhibited, cell viability was persistently reduced to below 20% during the cell culture period. NC-190 cauced a dose- and time-dependent reduction in DNA synthesis. The inhibitions of RNA and protein synthesis were less than that of DNA synthesis. Spectroscopic studies of NC-190 mixed with calf thymus DNA demonstrated that NC-190 was capable of interacting with DNA. However, DNA thermal denaturation studies suggested that intercalation of NC-190 was weak in comparison with those of classical intercalating drugs.     

Antitumor Effect of DX-8951, a Novel Camptothecin Analog, on Human Pancreatic Tumor Cells and Their CPT-11-resistant Variants Cultured in vitro and Xenografted into Nude Mice

DX-8951 is a novel water-soluble derivative of camptothecin. We evaluated the effects of DX-8951 on the growth of several pancreatic tumor cell lines in vitro and in vivo. In vitro cytotoxic activity of DX-8951 against SUIT-2 and KP-1N cells, as indicated by IC₅₀ value, was several times more potent than that of SN-38, an active metabolite of CPT-11, and dozens of times more potent than that of SK&F104864 (topotecan). DX-8951 also showed the greatest cytotoxicity against CPT-11-resis-tant variants, SUIT-2/CPT-11 and KP-1N/CPT-11 cells, and the cross-resistance of these cells to DX-8951 was lower than that to SN-38 and SK&F104864. Topoisomerase 1 inhibitory activity of DX-8951 was about three-fold stronger than that of SN-38, as measured in crude nuclear extract obtained from SUIT-2 cells. DX-8951 induced DNA fragmentation, a specific feature of apoptosis, in SUIT-2 cells more effectively than SN-38. DX-8951 exhibited potent antitumor effects against SUIT-2 in a solid tumor model and in a liver metastasis model, in which tumor cells were xenografted sub-cutaneously and intrasplenically, respectively, into nude mice. The in vivo effects were closely similar to or somewhat superior to those of CPT-11, DX-8951 also showed significant antitumor effects against SUIT-2/CPT-11 solid tumors, against which CPT-11 had no effect. These results suggest that, on the basis of its strong antitumor activity and effectiveness against CPT-11-resistant tumors, DX-8951 may be a useful therapeutic agent in the treatment of human cancer. The potent cytotoxicity of DX-8951 may result from strong inhibition of topoisomerase I, which may then trigger apoptotic cell death.     

TL对人胰腺癌细胞裸鼠移植瘤的治疗作用及抑制血管生成的研究

目的：探讨雷公藤内酯醇（TL）对人胰腺癌细胞SW1990移植瘤的生长及新生血管生成的抑制作用。方法：通过人胰腺癌裸鼠皮下移植实验，观察不同剂量TL对移植瘤生长抑制作用；应用免疫组化和RT-PCR研究裸鼠移植瘤组织VEGF表达变化，计算肿瘤组织微血管密度（MVD）。结果：各实验组（TL0．125、0．25和0．5mg·^-1kg·day^-1）抑瘤率分别达到66．16％、78．14％和89．92％，与对照组相比，肿瘤生长明显受抑，并具有剂量和时间依赖性。对照组和各实验纽瘤组织MVD分别为36．25±8．64、22．75±6．67、17．65±7．11和9．87±3．34（P〈0．01）；TL抑制移植瘤VEGF基因和蛋白表达．且VEGF基因下调与MVD的减少具有相关性（r=0．7424，P〈0．01）．结论：TL具有显著的抗胰腺癌移植瘤作用．其机制可能与抑制肿瘤新生血管生成有关。     

Cdx2过表达对裸鼠人胃癌移植瘤生长和转移的影响

目的观察Cdx2基因过表达对裸鼠人胃癌移植瘤生长和转移的影响。方法利用脂质体将pCMV-Cdx2-HA质粒或pCMV-HA质粒分别转染人胃癌MGC-803细胞,命名为MGC-803/Cdx2细胞或MGC-803/EV细胞。将两种细胞分别注射入裸鼠近腋右背侧皮下,待皮下成瘤后将瘤组织接种于胃,建立裸鼠人胃癌移植瘤模型：接种MGC-803/Cdx2皮下瘤的裸鼠为实验组,接种MGC-803/EV皮下瘤的裸鼠为对照组;30 d后处死裸鼠,观察移植瘤生长、转移情况,并应用半定量逆转录-聚合酶链反应(RT-PCR）和Western blot技术检测移植瘤中Cdx2 mRNA和蛋白的表达。结果实验组肿瘤体积为(13.42±2.34）mm3,明显低于对照组的肿瘤体积(17.59±2.80）mm3(P<0.05）;实验组成瘤率(73.3%）低于对照组成瘤率(86.7%）;两组肿瘤转移情况比较,差异无统计学意义(P>0.05）;实验组肿瘤组织Cdx2 mRNA和蛋白表达明显增加(P<0.05）。结论 Cdx2过表达抑制裸鼠人胃癌移植瘤的生长,但对肿瘤转移无明显影响。