Vascular endothelial growth factor immunoneutralization in combination with cisplatin reduces EAC tumor growth

In the present study, we evaluated the effects of a neutralizing anti-Vascular Endothelial Growth Factor (VEGF) polyclonal antibody on murine EAC tumor growth both in vitro and in vivo. Furthermore, we investigated if in the presence of effective VEGF blockade, a conventional chemotherapeutic drug Cisplatin could be effective, and if so would there be an additive effect of the combination regimen. An in vitro cell proliferation assay using MTT kit showed that VEGF antibody alone inhibited proliferation of EAC cells significantly in all the three time intervals (p<0.05). But cisplatin treatment in combination with VEGF antibody resulted in highly significant inhibition (p<0.001) of cell proliferation. Apoptosis assay by FACS analysis showed that VEGF antibody-cisplatin combination treatment induced apoptosis in cultured EAC cells. Intraperitoneal administration of VEGF antibody (100 mug/dose) and cisplatin (0.5 mg/kg/dose) combination was observed to be more effective in reducing tumor burden and increasing life span when compared to VEGF antibody or cisplatin treatment alone in EAC solid tumor bearing mice. In EAC ascites tumor model, all the three types of treatment inhibited tumor burden and increased life span, but the inhibition was less compared to EAC solid tumor bearing mice. VEGF antibody singly and in combination with cisplatin reduced neoangiogenesis and vascular hyperpermeability. However, it is clear from the results that the combination treatment had no additive effect in reducing vascular hyperpermeability. Serum VEGF was not reduced significantly after treatment in EAC ascites tumor bearing mice, whereas in EAC solid tumor bearing mice it was reduced significantly after treatment. The results clearly show that though alone cisplatin showed antitumor efficacy but it had no significant inhibitory effect on neoangiogenesis and vascular hyperpermeability. Thus the present study suggests that anti-VEGF agent can be combined with traditional treatment modalities to ensure more effectiveness.     

Dendrimer-platinate: a novel approach to cancer chemotherapy

A polyamidoamine (PAMAM) dendrimer generation 3.5 with a sodium carboxylate surface was conjugated to cisplatin giving a dendrimer-platinate (dendrimer-Pt; 20-25 wt% platinum) which was highly water soluble and released platinum slowly in vitro. In vivo the dendrimer-Pt and cisplatin were equi-active i.p. against i.p. L1210, and at high dose dendrimer-Pt given i.p. showed activity against i.p. B16F10 whereas cisplatin did not. Additionally, when administered i.v. to treat a palpable s.c. B16F10 melanoma, the dendrimer-Pt displayed antitumor activity whereas cisplatin was inactive. Measurement of platinum levels in blood and tissues after i.v. injection of cisplatin (1 mg/kg) or dendrimer-Pt (15 mg/kg)-the maximum tolerated dose (MTD) of these compounds-showed selective accumulation of the dendrimer-Pt in solid tumor tissue by the EPR effect (a 50-fold increase in area under curve compared with cisplatin). The dendrimer-Pt was also less toxic (3- to 15-fold) than cisplatin and thus has potential for further investigation as a novel antitumor approach.     

Antimetastatic activity of MONCPT in preclinical melanoma mice model

Previous study demonstrated that MONCPT, a topoisomerase I inhibitor, exhibited potent anti-proliferation and anti-angiogenesis activity in vitro and in vivo. In this study, we report the efficacy of MONCPT against the development of melanoma metastasis by an intravenous injection of green fluorescent protein-transfected mice melanoma carcinoma (B16F10-GFP) cells in C57BL/6 mice. MONCPT (2.0, 5.0 and 12.5 mg/kg/2 days) markedly decreased B16F10-GFP pulmonary metastases by 12.8%, 53.1% and 76.3%, respectively; whereas higher doses of MONCPT (31.0 mg/kg/2 days) significantly inhibited the tumor growth of B16F10 xenograft model. In the in vitro experiment, MONCPT suppressed the B16F10-GFP cell invasion and migration without affecting cell survival. Further studies demonstrated that MONCPT decreased the secretion of matrix metalloproteinase (MMP)-9 and VEGF, and reduced the protein expression of HIF-1α as well as the phosphorylation level of ERK in B16F10-GFP cells. These in vivo and in vitro results indicate that MONCPT possesses both the potent antimetastatic ability and the tumor growth-inhibition activity, and the dual function promises MONCPT as a potential therapeutic agent for tumor metastasis and tumor growth of melanoma carcinoma.     

CCI-779 plus cisplatin is highly effective against human melanoma in a SCID mouse xenotranplantation model

BACKGROUND: This study set out to investigate the antitumor effects of a treatment strategy combining the mTOR inhibitor CCI-779 with cisplatin in vitro and in a human melanoma SCID mouse model. METHODS: In vitro 518A2, Mel-JUSO or 607B cell lines were incubated with CCI-779, cisplatin and CCI-779 plus cisplatin. Based on these results, a 4-group, parallel, controlled experimental study design was initiated in vivo. SCID mice were injected with melanoma cells, and after the development of tumors the mice received daily injections of CCI-779 or solvent. On treatment days 2 and 6 cisplatin or mock solution were administered. RESULTS: In vitro a synergistic antitumor effect was observed for the treatment regimen of CCI-779 plus cisplatin. In SCID mice after 2 weeks of therapy with CCI-779 plus cisplatin 4 of 6 tumors of the 518A2 cell line were completely eradicated. In the two remaining 518A2 xenografts this treatment strategy reduced the tumor weight by 94 +/- 9% compared to solvent. CCI-779 plus cisplatin also exerted a significant antitumor effect in Mel-JUSO and 607B xenografts compared to mock-treated animals. CONCLUSION: We provide circumstantial evidence that the use of CCI-779 plus cisplatin might qualify as a promising strategy in the treatment of human melanoma.     

Antitumor effect of cytosine deaminase／5-fluorocytosine suicide gene therapy system mediated by Bifidobacterium infantis on melanoma

Aim: To construct a Bifidobacterium infantis/CD targeting gene therapy system and observe the antitumor effect of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system mediated by Bifidobacterium infantis on melanoma in vitro and in vivo. Methods: A recombinant CD/pGEX-1 LamdaT plasmid was transfected into Bifidobacterium infantis by electroporation. Bifidobacterium infantis transfected by recombinant CD/pGEX-1LamdaT plasmid was incubated with 5-FC anaerobically. Then the supernatant fluid was collected and added to melanoma B 16-F10 cells to observe the killing effect for B 16-F10 cells.Mice were inoculated with melanoma B 16-F10 cells to establish animal models.The mice were then injected with 5-FC and Bifidobacterium infantis transfected by recombinant CD/pGEX-1LamdaT plasmid. Results:Two segments of approximate 4.9kb and 1.3 kb were extracted from the 6.2 kb recombinant plasmid, which were equal to the size of the pGEX-1LamdaT plasmid and CD gene, respectively.Sequencing results showed that the full length and sequence of nucleotide acid of the inserted gene in extracted recombinant plasmid was completely identical to the CD gene. In vitro, B 16-F10 cells treated by supernatant fluid were remarkably damaged morphologically, and the cell growth was significantly inhibited. Experiments on the mice melanoma model showed that after treatment with a combination of transfected Bifidobacterium infantis and 5-FC, the tumor volume was significantly inhibited compared with controls. Conclusion: The foreign gene,CD gene, was correctly inserted into pGEX-1LambdaT plasmid and transferred into Bifidobacterium infantis. CD/5-FC suicide gene therapy system mediated by Bifidobacterium infantis demonstrated a good antitumor effect on melanoma in vitro and in vivo.     

铂类抗癌新药双环铂的体内外抗肿瘤活性

目的观察铂类抗癌新药双环铂的体内外抗肿瘤活性及其对细胞周期的影响。方法MTT法观察双环铂对人肿瘤细胞增殖的抑制作用;小鼠动物肿瘤模型观察双环铂对肿瘤的体内抑制作用;碘化丙锭PI染色流式细胞术分析药物所致人卵巢癌细胞A2780细胞的周期变化。结果双环铂于体外抑制多种人肿瘤细胞增殖,体内抑制小鼠肉瘤S180、肝癌Heps及黑色素瘤B16的生长,并导致A2780细胞S期细胞明显增加及G2/M期细胞少许增加。结论双环铂具有明显的体内外抗肿瘤活性,并影响肿瘤细胞的细胞周期分布。     

Hyperthermia-induced antitumor activity of thermosensitive polymer modified temperature-sensitive liposomes

Temperature-sensitive liposomes (TS-liposomes) have been studied for chemotherapeutic purposes to enhance the release of anticancer drugs at tumor sites. In this study, we prepared poly(N-isopropylacrylamide-co-acrylamide) (PNIPAM-AAM) and polyethylene glycol (PEG)-modified TS-liposomes (PETS-liposomes). PETS-liposomes significantly increased in vitro drug release in serum compared with PEG-fixed or PNIPAM-AAM-modified liposomes. Furthermore, incorporation of both PNIPAM-AAM and PEG into PETS-liposomes enhanced the stabilities of liposomes in serum by inhibiting protein adsorption. In addition, to investigate the therapeutic efficacy of doxorubicin (DOX)-loaded PETS-liposomes, the in vivo antitumor activity of liposomes in combination with hyperthermia was evaluated in a B16F10 melanoma tumor-bearing mouse model. PETS-liposomes showed much higher levels of tumor growth inhibition than PEG-fixed or PNIPAM-AAM-modified TS-liposomes. Moreover, the antitumor activity of PETS-liposomes was enhanced significantly when they were administered in combination with hyperthermia. PETS-liposomes were found to be highly efficacious carriers for the in vivo delivery of anticancer drugs, and to have potential anticancer applications in combination with hyperthermia.     

乙烷硒啉与顺铂或氟尿嘧啶联合应用对胃癌BGC-823的治疗作用

目的观察乙烷硒啉与顺铂或氟尿嘧啶联合应用对胃癌BGC-823的体内、外抗肿瘤作用。方法MTT法测定5、10、20、40μmol·L~(-1)乙烷硒啉单药及固定其浓度为5μmol·L~(-1)与顺铂或氟尿嘧啶联合时对BGC-823的生长抑制作用。建立裸鼠移植瘤模型,采用乙烷硒啉、顺铂、氟尿嘧啶单药及乙烷硒啉与后两者联合的不同给药方案,观察抗肿瘤作用。结果乙烷硒啉对BGC-823有明显增殖抑制作用,24、48、72h的IC_(50)值分别是30.23、19.70和11.67μmol·L~(-1),联合后效果明显增强(P<0.05)。体内实验,联合组肿瘤增长率明显降低,与单药组有非常显著差异(P<0.01)。结论乙烷硒啉单药表现明显抗肿瘤作用,与顺铂或氟尿嘧啶联合后可以增效。     

Possible reduction of hepatoma formation by Smmu 7721 cells in SCID mice and metastasis formation by B16F10 melanoma cells in C57BL/6 mice by Agaricus blazei murill extract

Agaricus blazei Murill extract (ABM) has been reported to possess antitumor effects. In this study, the role of ABM in tumor growth and metastasis in vivo was evaluated in experimental Smmu 7721 hepatoma cells in severe combined immunodeficiency (SCID) mice and B16F10 melanoma cells lung metastasis in C57BL/6 mice. For the tumor growth model, the size of the liver tumor mass was about 10 mm to 20 mm in the control group. In comparison with the control group, the tumor mass seem to grow slowly with ABM treatment, especially at the high dose. For the tumor metastasis model, after a six-week treatment, the survival rates of B6 mice were 0%, 30%, 10% and 50% for control group, low, median and high concentration ABM treatment groups, respectively. The survival rate showed that pretreatment of C57BL/6 (B6) mice with ABM lengthened their lifespan after tumor cell inoculation, which supports the notion that ABM successfully reduced lung metastasis formation by B16F10 melanoma cells. The treatment effect was dependent on the concentration of ABM for tumor growth and metastasis in these models.     

Antitumor activity of N-phosphonacetyl-L-aspartic acid in combination with nitrobenzylthioinosine

N-Phosphonacetyl-L-aspartic acid (PALA) resistance may be due to the ability of tumor cells to utilize preformed circulating pyrimidine nucleosides, thereby overcoming the block of de novo pyrimidine biosynthesis which PALA causes. To test this hypothesis we examined the effects of PALA and nitrobenzylthioinosine (NBMPR) alone and in combination on B16 melanoma cells in vitro using a clonogenic assay and in vivo using growth delay. In medium containing purine and pyrimidine nucleosides at a final concentration of 28 microM, exposure to PALA (100 microM) alone or to NBMPR (10 microM) alone for periods up to 72 hr did not result in any cytotoxicity. However, exposures to PALA (100 microM) plus NBMPR (10 microM) resulted in a decrease in clonogenic survival to 0.011 at 72 hr. In medium without nucleosides, PALA (100 microM) exposure for 72 hr caused a similar decrease in survival to 0.015, whereas NBMPR (10 microM) had no effect on survival. The addition of uridine resulted in a concentration-dependent reversal of the cytotoxic effects of PALA. C57 Bl female mice bearing B16 melanoma were treated intraperitoneally daily for 4 days with PALA, the phosphate of NBMPR (NBMPR-P), or PALA plus NBMPR-P. PALA, 300 mg/kg daily X 4, resulted in a 6-day tumor growth delay but NBMPR-P, 100 mg/kg daily X 4, had no effect. PALA, 150 mg/kg daily X 4, plus NBMPR, 50 or 100 mg/kg daily X 4, resulted in a 6-day tumor growth delay also. These studies demonstrate that: (1) circulating pyrimidine nucleosides are determinants of the cytotoxic effects of PALA; (2) in vitro PALA and NBMPR combine to cause significant cytotoxicity whereas either agent alone has no effect; (3) in vivo the combination of PALA and NBMPR-P results in the same antitumor affect as PALA alone at twice the dose; and (4) due to an increase in animal toxicity, no therapeutic advantage could be demonstrated for the combination over PALA alone in vivo. We conclude that the cytotoxic effect of PALA is modulated by the levels of the preformed circulating nucleosides and that combining PALA with an inhibitor of salvage pyrimidine uptake would not increase the therapeutic efficacy of PALA because of an increase in toxicity.     

Novel anticancer prodrugs of butyric acid. 2.

The antitumor activity of novel prodrugs butyric acid was examined. The in vitro effect of the compounds on induction of cytodifferentiation and on inhibition of proliferation and clonogenicity showed that (pivaloyloxy)methyl butyrate (1a) (labeled AN-9) was the most active agent. SAR's suggested that its activity stemmed from hydrolytically released butyric acid. In vivo, 1a displayed antitumor activity in B16F0 melanoma primary cancer model, manifested by a significant increase in the life span of the treated animals. Murine lung tumor burden, induced by injection of the highly metastatic melanoma cells (B16F10.9), was decreased by 1a. It also displayed a significant therapeutic activity against spontaneous metastases which were induced by 3LL Lewis lung carcinoma cells. Moreover, 1a has the advantage of low toxicity, with an acute LD50 = 1.36 +/- 0.1 g/kg (n = 5). These results suggest that 1a is a potential antineoplastic agent.     

Methylglyoxal bis(butylamidinohydrazone) exhibits antitumor effect on human malignant melanoma cells but reduces the antitumor action of cisplatin.

The antitumor effect of a polyamine biosynthetic pathway inhibitor methylglyloxal bis(butylamidinohydrazone) (MGBB) on human malignant melanoma (HMG) cells and its combination effect with cisplatin were investigated. The growth of cultured HMG cells was inhibited in a dose dependent manner by either MGBB or cisplatin; complete inhibition of cell proliferation was attained with 5 micrograms/ml of MGBB or 50 micrograms/ml of cisplatin. Pretreatment of HMG cells with MGBB diminished the antitumor action of cisplatin. The cultured HMG cells were inoculated in nude mice and aliquots of the resulting solid tumors (HMG tumor) were transplanted. The growth of transplanted HMG tumors in mice was inhibited markedly by cisplatin (3.8 mg/kg) and moderately by MGBB (10 or 20 mg/kg). The in vivo antitumor effect of cisplatin was also reduced by combined treatment with MGBB.     

Antimetastatic potential of vernolide-A, a sesquiterpenoid from Vernonia cinerea L

The inhibitory effect of vernolide-A (C(21)H(28)O(7)) on lung metastasis induced by B16F-10 melanoma cells was studied using C57BL/6 mice. Vernolide-A was administered in three different modalities such as simultaneously with tumor, prophylactic to tumor and after tumor development. Maximum inhibition in the metastasis was observed when vernolide-A was administered simultaneously with tumor. There was 89.39% inhibition of lung tumor nodule formation and 88.51% increase in the life span of metastatic tumor-bearing animals. Highly elevated levels of lung hydroxyproline, lung uronic acid, lung hexosamine, serum sialic acid, serum γ-glutamyl transpeptidase (GGT) and serum vascular endothelial growth factor (VEGF) in the metastatic control animals were found to be significantly lowered in the vernolide-A-treated animals. Histopathological analysis of lung tissues also correlated with these results. Vernolide-A administration downregulated the expression of matrix metalloproteinase-2 (MMP-2), MMP-9, extracellular-signal-regulated kinase-1 (ERK-1), ERK-2 and VEGF in the lung tissue of B16F-10 melanoma challenged animals. In the in vitro system, vernolide-A showed a significant inhibition of invasion of B16F-10 melanoma cells across the collagen matrix. Vernolide-A treatment also inhibited the migration of B16F-10 melanoma cells across a polycarbonate filter in vitro. Vernolide-A could inhibit MMP-2 and MMP-9 protein expression in gelatin zymographic analysis of B16F-10 cells. (3)H-thymidine proliferation assay showed that vernolide-A could inhibit the proliferation of B16F-10 melanoma cells in vitro. These results indicate that vernolide-A could inhibit the metastatic progression of B16F-10 melanoma cells in mice.     

STAT3-siRNA induced B16.F10 melanoma cell death: more association with VEGF downregulation than p-STAT3 knockdown

STAT3 knockdown by small interfering RNA (siRNA) has been described to inhibit carcinogenic growth in various types of tumors. Earlier we have reported delivery of siRNA by oleic acid- and stearic acid-modified-polyethylenimine and enhancement of silencing of STAT3 by small interfering RNA (siRNA) in B16.F10 melanoma cell lines and consequent tumor suppression. Present investigation mainly focused on the downstream events involved in B16.F10 melanoma cell death and consequent tumor suppression following knockdown of p-STAT3 by siRNA. Lipid-substituted polyethylenimine (PEI)-p-STAT3-siRNA were prepared and characterized by measuring its N/P ratio, zeta potential, size, association and dissociation with siRNA. B16.F10 melanoma cells were treated with six different concentrations of PEI-p-STAT3-siRNA (200, 100, 50, 25, 12.5 and 6.25?nM). Downregulation of p-STAT3 and VEGF were studied using western blot and ELISA in association with the melanoma cell death. PEI-p-STAT3-siRNA hydrodynamic diameter ranged from 110 to 270?nm. PEI assisted p-STAT3-siRNA delivery exhibited increased uptake by B16.F10, when analyzed by fluorescent and confocal microscopy along with flowcytometry. It induced concentration-dependent knockdown of the p-STAT3 that also downregulated VEGF expression in similar fashion and induced B16.F10 cell death. Higher concentrations of p-STAT3-siRNA appear to significantly downregulate the VEGF expression via p-STAT3 knockdown. Decreasing survival of B16.F10 cells with the increasing concentration of p-STAT3-siRNA significantly correlated with VEGF downregulation, not with p-STAT3 expression. Data suggest that VEGF downregulation following knockdown of p-STAT3 may be a key event in survival reduction in B16.F10 melanoma cells and.     

The cellular uptake and anti-tumor activity of conjugated linoleic acid-paclitaxel-loaded iRGD-modified lysolipid-containing thermosensitive liposomes

In the present study, we prepared the iRGD-modified lysolipid-containing thermosensitive liposomes (LTSL) containing conjugated linoleic acid-paclitaxel (CLA-PTX), also known as iRGD-LTSL-CLA-PTX. The in vitro cellular uptake and invitro cytotoxicity of iRGD-LTSL-CLA-PTX were evaluated in B16-F10 melanoma cells. The in vivo anti-tumor effect of iRGD-LTSL-CLA-PTX was investigated using B16-F10 tumor-bearing C57BL/6 mice. The results of the cellular uptake experimentindicated that the increased cellular uptake of CLA-PTX in the iRGD-LTSL-CLA-PTX-treated groups was 2.05-, 3.31- or 4.83-foldcompared with that in the SSL-CLA-PTX group after a 2-, 4- or 6-h incubation at 42°C, respectively. The in vivo antitumor results showed that iRGD-LTSL-CLA-PTX/heat significantly inhibited the growth of B16-F10 tumors compared with the CLA-PTX solution (LTSL-CLA-PTX, LTSL-CLA-PTX/heat and iRGD-LTSL-CLA-PTX) (P<0.01). In conclusion, the antitumor effect of iRGD-LTSL-CLA-PTX was confirmed on B16-F10 melanoma in vitro and in vivo, which was induced by both the effect of iRGD and LTSL.     

YoshixolTR inhibits B16 melanoma cell growth in vivo and induces apoptosis-like (quantum thermodynamic) cell death.

In this report, antitumor effects of YoshixolTR in vivo and in vitro were investigated in B16 melanoma cells. For in vivo experiments, the present study shows a dramatic inhibition of tumor growth of B16 melanoma transplanted on the leg or intraperitoneal cavity after treatment with YoshixolTR intraperitoneally. A proliferation of B16 cells in vitro was inhibited by YoshixolTR in a dose-and time-dependent manner. YoshixolTR induced apoptosis-like cell death in histological observations (phase-contrast, scanning and transmission electron microscopy), DNA fragmentation, and a smaller increase in lactate dehydrogenase (LDH) as a marker of cell leakage. Immunohistochemical investigation of cytoskeletal components, such as actin and tubulin, showed a cell wall disruption of B16 melanoma cells and a nuclear extrusion after the treatment with YoshixolTR. Treatment with YoshixolTR in vitro showed an arrest at the G0/G1 stage of the cell cycle, followed by a flow cytometric measurement. As a possible physiological mechanism of YoshixolTR on B16 melanoma cells, intracellular Ca++ was measured with Fura-2 technique. An adequate concentration of YoshixolTR, which induces apoptosis-like cell death, showed a decrease in intracellular free Ca++ concentration. In conclusion, YoshixolTR has an antitumor potency with a new biological mechanism of cell growth, proliferation, and differentiation, including cellular signalling pathways, and is a new candidate for an ideal chemotherapeutic agent against malignant tumors.     

Antimelanoma activity of 1,3,4-thiadiazolium mesoionics: a structure-activity relationship study

The effect of a series of 4-phenyl-5-(2'-Y, 4'-X or 4'-X-cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chlorides was evaluated against B16-F10 murine melanoma cells in vitro and against tumors resulting from implanted B16-F10 cells in C57BL/6 mice. These compounds differ from each other only at the cinnamoyl ring substituent (MI-J, X=OH; MI-2,4diF, X=Y=F; MI-4F, X=F and MI-D, X=NO2). The results were compared with those obtained for MI-D, which has already been shown to be a potent and promising drug against melanoma. On exposure of B16-F10 cells to MI-D, MI-2,4diF and MI-4F, all of them at the same micromolar concentration (50 microM) decreased the cell viability to 8, 50 and 22%, respectively, while MI-J did not show any significant effect under the same conditions. However, low doses such as 10 microM MI-D were sufficient to impair cell growth over 72 h, but for MI-2,4diF and MI-4F the effect on B16-F10 proliferation was only observed at a concentration of 25 microM. Furthermore, MI-4F had a slightly better effect than MI-2,4diF in vitro; its effect on tumor growth in vivo was not significant. MI-D inhibited tumor growth by 77%. The greater effectiveness of MI-D compared with MI-2,4diF, MI-4F and MI-J against B16-F10 melanoma cells is probably due to its stronger electron-withdrawing group (NO2), which increases the positive charge on the mesoionic ring and allows extensive conjugation of the side-chain with the exocyclic moiety. This seems to be important for degree of anti-tumor activity of these compounds.     

Combination Therapy of Heparin–Deoxycholic Acid Conjugate and Doxorubicin against Squamous Cell Carcinoma and B16F10 Melanoma

Purpose Our previous study confirmed that heparin–deoxycholic acid conjugate (HD) had a potent antiangiogenic effect and safety to use for long-term treatment. Herein, the combined therapeutic effect of HD and doxorubicin (DOX) was evaluated against squamous cell carcinoma (SCC7) and B16F10 melanoma. Methods The inhibitory effect of cell proliferation and cellular uptake of HD was studied in SCC7 and B16F10. The combination effects of HD and DOX were evaluated by measuring cytotoxicity and apoptosis as well as tumor growth and apoptosis in vivo against SCC7 and B16F10 tumor-bearing mice. Results HD displayed potent inhibitory effect on SCC7 and B16F10 cell proliferation, but it showed a low cytotoxic effect. Concurrent treatment of HD and DOX displayed enhanced cytotoxic effects and apoptosis on SCC7 and B16F10. The cellular uptake of HD and DOX was affected by the collective cytotoxic effects of these two drugs: each drug suppressed the tumor growth, and their combined treatment enhanced apoptosis and collectively inhibited the tumor growth of SCC7 and B16F10 in vivo. Conclusion These results demonstrated that HD with cytostatic and antiangiogenetic activities, enhanced the antitumor activity of DOX against SCC7 and B16F10, and the combined treatment of these two drugs might have enhanced therapeutic efficacy.     

T-钙黏蛋白联合顺铂对黑色素瘤顺铂 耐药株的作用研究

摘要：目的 探讨T-钙黏蛋白联合顺铂对黑色素瘤顺铂耐药株的作用。方法 采用大剂量冲击和逐步增加剂 量相结合的方法诱导建立小鼠黑色素瘤B16F10顺铂耐药细胞株（CDDP-R B16F10）。MTT法检测CDDP-R B16F10 的增殖能力。将T-钙黏蛋白转染肿瘤细胞。分别采用反转录聚合酶链式反应（RT-PCR）和免疫组化SP法检测转染 后T-钙黏蛋白mRNA和蛋白的表达。实验将CDDP-R B16F10细胞分为空白对照组、pEGFP-N1组、pEGFP-N1-T cadherin组、顺铂组、pEGFP-N1联合顺铂组、pEGFP-N1-T-cadherin 联合顺铂组。采用Wound-healing 划痕实验和 transwell侵袭实验检测T-钙黏蛋白联合顺铂对CDDP-R B16F10细胞迁移和侵袭力的影响。结果 成功建立黑色素 瘤顺铂耐药细胞株。MTT法结果显示,CDDP-R B16F10细胞增殖能力与B16F10细胞相比差异无统计学意义（P＞ 0.05）。RT-PCR和免疫组化SP法检测表明,转染后细胞可稳定转录和表达T-钙黏蛋白。pEGFP-N1-T-cadherin联 合顺铂组细胞迁移率和穿膜细胞数低于pEGFP-N1-T-cadherin组（P＜0.05）,而pEGFP-N1-T-cadherin组低于空白 对照组、pEGFP-N1 组、顺铂组和 pEGFP-N1 联合顺铂组（P＜0.05）。析因分析显示,T-钙黏蛋白与顺铂联合对 CDDP-R B16F10细胞迁移率及侵袭力的抑制有交互作用（P＜0.05）。结论 T-钙黏蛋白可恢复顺铂对黑色素瘤顺 铂耐药细胞株迁移及侵袭力的抑制作用。