Antitumor effect of intermittent oral administration of UFT against human rectal cancer xenografted in nude mice

Effect and toxicities of oral administration of UFT were examined with tumor xenografts (COK-7LiM) in nude mice. Special attention was paid to the differences between daily (Q1D X 9) and intermittent (Q4D X 3) treatments with this agent. The optimal doses of UFT were determined on the basis of the maximal tolerated dose of the agent in nude mice. It was remarkable that the chemotherapeutic effect by intermittent administration of UFT showed a significantly better result than that by daily administration. No difference was seen in the toxicities between the two methods of administration of UFT. Moreover, the concentration of 5-FU in the tumor tissue treated with UFT intermittently was significantly higher than that by daily administration method.     

Antitumor effect of monoclonal antibody-carboplatin conjugates in nude mice bearing human ovarian cancer cells

Background. The antitumor effect and toxicity of immunoconjugates were studied in nude mice bearing a human ovarian cancer cell line, OVA-1. Methods. We studied the tissue distribution of an anti-cytokeratin-8 monoclonal antibody (6D7) in OVA-1-bearing nude mice by giving 6D7 labelled with ¹²⁵I. The immuno conjugate consisted of 6D7 and carboplatin (6D7-conjugate), coupled via carboxymethyl dextran, and this was intraperitoneally administered to OVA-1 bearing nude mice. The tumor volume and the body weight were measured for 5 weeks. Tissue platinum concentrations in the OVA-1 tumor, blood, liver, kidney, and spleen, were measured from 3 to 120 min after administration of the conjugate. The results were compared with those in nude mice treated with nonspecific mouse IgG coupled with carboplatin (IgG-conjugate) or carboplatin alone. Results. The coupling rate of the drug to 6D7 was approximately 80%, and was stable over several measurements at various times. In-vivo accumulation of 6D7 labelled with ¹²⁵I in the OVA-1 tumors was significantly higher than that in mice that received nonspecific mouse- IgG-¹²⁵I, with tumor/ blood radioactivity ratios of 14.0 and 1.28, respectively. The tumor growth rate in mice that were administered 6D7-conjugate was (at a maximum) 40% lower than the tumor growth rate in mice administered carboplatin. The body weight of the mice that received 6D7-conjugate did not decrease during the 5-week observation period, while the body weight of the mice that received carboplatin decreased by a maximum of 10%. In addition, upon administration of 6D7-conjugate, the platinum concentration in the tumor was maintained for a longer period than after the administration of carboplatin alone. Conclusions. The tumor growth suppression effect was significantly higher in the mice bearing the OVA-1 tumor that received 6D7-conjugate than in the animals that received carboplatin alone. This difference could be caused by differences in the platinum concentrations in the tumor between the two groups. Received: November 9, 1998 / Accepted: March 23, 1999     

Level of 5-FU in cancerous and normal tissues of nude mice after oral administration of tegafur coadministered with uracil (UFT)

In order to investigate the effect of UFT, a new antitumor agent, 5-fluorouracil (5-FU) levels in serum and various tissues were measured by the gas chromatographic-mass fragmentographic method. The subjects used for the study were nude mice which had received implants of human endometrial carcinoma. The results were as follows: As compared with tegafur, the concentration of 5-FU in serum rose quickly when UFT was administered, and the values were clearly high. The concentration of 5-FU obtained in tumor tissues with the use of UFT were 2.5 times higher than those obtained by the use of tegafur. Even with one third of the dose of UFT, values were still 1.5 times higher. In normal tissues, the administration of UFT against that of tegafur resulted in higher concentrations of 5-FU. On the other hand, when one third of the dose of UFT was used, 5-FU concentrations in major organs, such as the liver or kidney, showed clearly low values. Based on these findings, it became clear that the 5-FU concentration in tumor tissue is specifically raised by tegafur coadministered with Uracil (UFT), while such an effect is prevented from proceeding in normal tissue.     

Response of human renal cancer to UFT in nude mice

A primary human renal cell carcinoma was developed as a xenograft (NT-25) and maintained by serial transplantation in nude mice. The effect of UFT on this neogrowth was tested and evaluated as well its distribution in the animal tissues. The concentration of UFT was higher in tumor tissues than that in other tissues and in the animal experimentation UFT was found to be effective on human renal cell carcinoma.     

5-FU concentration in tumor tissue and the antitumor effect in patients with gastric cancer after oral administration of UFT

Serum and tumor tissue concentration of FT, 5-FU and uracil were measured in 23 patients with gastric cancer who were administered UFT preoperatively. The degeneration of cancer cells was evaluated histologically and the correlation between 5-FU concentration in the tumor tissue and the antitumor effect was assessed. The average concentration of 5-FU in tumor tissue (0.122 microgram/g) was significantly higher than that in normal gastric tissues. Serum 5-FU concentration was very low, suggesting no accumulation of 5-FU in blood. A positive correlation between the concentration of 5-FU and uracil in tumor tissues was found. A 5-FU level higher than 0.05 microgram/g was frequently demonstrated in tumor tissue, resulting in moderate degeneration of cancer cells in many cases. When tumors were classified according to histological type, intratumoral 5-FU concentration was not always correlated with degeneration of cancer cells. The above results suggested that UFT was a very effective drug for stomach cancer because of high tumor affinity for 5-FU, but that it is necessary to consider the sensitivity of tumor cells to antitumor drugs in order to obtain an excellent antitumor effect.     

5-FU concentration in the tissues (tumor and lymph node) of breast cancer patients given preoperative administration of UFT and FT

In 16 patients with breast cancer who were administered UFT or FT-207 (UFT: 9 cases, FT-207: 7 cases) for a were prior to surgery, we studied the concentrations of 5-FU in the blood and tumor tissues, and in normal and metastatic lymph nodes sampled during surgery. As a result, a high level of 5-FU was found in tumors, especially in metastatic lymph nodes, in the patients who were administered UFT. On the other hand, no significant difference was found between the 5-FU levels of blood in UFT- and FT-treated patients. These facts suggest that UFT can be expected to increase antitumor activity without side effects, especially in cases of metastatic lymph nodes.     

Antitumor effect of docetaxel against human esophagus tumor cell lines and tumor xenografts in nude mice

The antitumor effect of docetaxel against cultured human esophagus tumor cell lines and tumor xenografts in nude mice was investigated. In the in vitro study, docetaxel showed concentration-dependent inhibition of the growth of 4 tumor cell lines having different degrees of differentiation (T. T, TE-5, TE-9 and TE-15) with IC(50) values ranging from 0.84 to 1.68 ng/ml when exposed for 72 h. These values represent ca. 1/2,700-1/1,400 of the mean maximum plasma concentration of 2.27 microg/ml attained in the clinical setting. In addition, the activity was found to be ca. two-fold stronger than that of paclitaxel, and much more potent than fluorouracil and cisplatin. The in vivo antitumor effect of docetaxel was also investigated against xenografts of human esophagus squamous cell carcinoma H-190 (highly differentiated) and H-204 (moderately differentiated) in nude mice. Docetaxel at its Maximum Tolerated Dose (MTD) and the lower dose (4.5, 6.7 mg/kg/dose, q 4 d x 3, iv) showed a significant growth inhibition of ca. 100% against H-190 tumor, resulting in the tumor shrinkage. Paclitaxel (6.7, 10 mg/kg/dose, q 4 d x 3, iv) showed a tumor-shrinking effect similar to that seen with docetaxel. In the H-204 xenograft model, docetaxel (4.5, 6.7, 10 mg/kg/dose) exhibited a dose-dependent effect in delaying the tumor growth, while paclitaxel failed to suppress the tumor growth even at its MTD. These results demonstrated that docetaxel has potent antitumor efficacy against human esophagus tumor cells, leading to the expectation that it will be useful as a therapeutic agent for esophagus cancer.     

Antitumor activities of ME 2303 on human gastrointestinal cancer xenografted to nude mice

The antitumor activity of ME 2303 was evaluated on 3 human stomach and 3 colon cancers xenografted to nude mice, which were established in our laboratory. The activity was compared with that of doxorubicin in terms of the inhibition of tumor growth and the histopathological changes. The dosage of ME 2303 was 35 or 50 mg/kg and that of doxorubicin was 5 mg/kg. Both drugs were administered intravenously 4 times at 5-day intervals. Thirty-five mg/kg of ME 2303 was effectively inhibited tumor growth against 3 lines, with marked efficacy against 2 lines. On the other hand, 50 mg/kg of ME 2303 was also effective against 4 lines tested (2 each of gastric and colorectal cancers), with marked efficacy against 3. In all, ME 2303 was more effective than doxorubicin except one of stomach cancer. The histopathological findings also revealed that 35 mg/kg of ME 2303 was equal or slightly superior to doxorubicin in efficacy. The side effects of ME 2303 such as weight loss were as mild as those with doxorubicin, except in the female mice administered 30 mg/kg of ME 2303 and no other adverse effect was observed. ME 2303 seems promising for clinical application in human since the increased efficacy in nude mice human xenograft might be found after more adequate modification of the dosage and administration schedule.     

Anti-tumour effect of UFT on human renal cell carcinoma heterotransplanted into nude mice

1) Using two histologically different human renal cell carcinomas heterotransplanted into nude mice, the antitumour effect of UFT was investigated, and an attempt was made to analyze the properties of the tumour strains where a drug efficacy was noted. 2) The two strains used were the JRC 1 strain (tumour doubling time of 9.4 days, clear cell type, papillary histologic pattern, grade 3) and the JRC 11 strain (tumour doubling time of 2.72 days, granular cell type, anaplastic histologic pattern, grade 4). 3) Two dose groups were set up, one receiving 10 mg/kg of tegafur (FT) and 22.4 mg/kg of uracil and the other receiving 20 mg/kg of FT and 44.8 mg/kg of uracil. Each group was further divided into an early administration group (start of administration 3 days after the tumour transplantation) and a late administration group (start of administration at a time when the transplanted tumour proliferated to weight of 100 to 300 mg). 4) Effect as noted in the tumour proliferation inhibition rate was seen only in the group receiving 20 mg/kg of FT and 44.8 mg/kg of uracil in both early and late administration groups of the JRC 1 strain. Among these groups only the early administration groups showed a histological positive effect. 5) The fact that the measured 5-FU intra-tumour concentration in the JRC 1 strain was only 1/4 that of the JRC 11 strain demonstrates more susceptibility of JRC 1 strain to UFT. Moreover, intratumoral concentration of 5-FU differed markedly even with the same administration method and dosage level. This result indicates that intra-tumour concentration will be different if the histological pattern differs.     

Relationship between the anti-metastatic effect of UFT and in vitro chemosensitivity to 5-FU in metastatic tumors from orthotopic implanted colon cancer in nude rats

We have investigated the correlation between the in vitro chemosensitivity to 5-FU, measured using the collagen gel droplet embedded culture drug sensitivity test (CD-DST), and the anti-tumor effect of UFT, a prodrug of 5-FU, in metastatic tumors from orthotopic implanted colon cancer in nude rats. Human colon cancer cells (KM12SM) were injected into the cecal wall of the nude rats. Five weeks later, the implanted cecal tumors were removed. Oral UFT (a daily dose of 30 mg/kg) was administered postoperatively for four weeks. After the UFT administration period, the lung and lymph nodes were analyzed macroscopically and microscopically. In vitro chemosensitivity to 5-FU in the lung and lymph node metastases was tested using CD-DST, and the enzymatic activities of thymidine synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) in the lung and lymph node metastases were measured. A daily administration of UFT produced an inhibitory effect on lung metastasis compared with the control group. However, there was no difference in the frequency of lymph node metastasis. The inhibition rate produced by 5-FU in CD-DST was significantly higher for lung metastases than for lymph node metastases. There was no difference in the TS and DPD activities between the metastatic tumoral tissues. These results suggest that the organ specificity of the anti-tumor effects of UFT on colon metastases may be determined by CD-DST of 5-FU for individual tumors. The TS and DPD activity in the tumoral tissues may not affect the organ specificity of the anti-tumor effect of UFT on colon metastases.     

含CpG寡核苷酸在人神经母细胞瘤裸鼠移植瘤模型中的抗肿瘤效应

背景与目的：含有非甲基化CpG二核苷酸的寡脱氧核苷酸（CpG oligonucleotides,CpGODN）序列可以模拟细菌DNA特征,作为“异己信号”刺激机体免疫系统,发挥抗肿瘤作用。本研究探讨在人神经母细胞瘤（neuroblastoma,NB）裸鼠移植瘤模型中,CpGODN是否可以通过调节非特异性免疫来介导抗肿瘤效应。方法：体外WST-1实验明确CpGODN对神经母细胞瘤细胞株SK—N—MC的生长影响,建立NB荷瘤动物模型,当肿瘤生长到皮下可触及时,随机分组后给予不同注射处理（生理盐水、non—CpGODN、CpGODN）、观察各组小鼠肿瘤生长情况,病理组织学方法检测各组肿瘤组织的异同,免疫荧光组化法检测自然杀伤细胞（natural kill cell,NK）和巨噬细胞的浸润。结果：体外实验证明CpGODN对SK—N—MC细胞无明显的直接细胞毒性及生长抑制作用。CpGODN处理组与non—CpGODN、生理盐水组相比,肿瘤细胞生长明显受到抑制[（0．14±0．03）cm^3vs．（2．97±0．40）cm^3、（3．80±1．12）cm^3,（P〈0．01）]。HE染色显示与肿瘤细胞生长活跃的对照组相比,CpGODN处理组肿瘤组织中有较多的炎性细胞浸润及大片坏死灶。免疫荧光染色发现CpGODN处理组与生理盐水组、non—CpGODN组相比较瘤体内有明显的NK、巨噬细胞浸润。结论：具有免疫刺激作用的CpGODN可能通过调节NK、巨噬细胞的活性来抑制NB生长,发挥抗肿瘤作用。     

白桦酯醇对人卵巢癌裸鼠移植瘤的抑制作用

目的：观察白桦酯醇对人卵巢癌裸鼠移植瘤的抑制作用及对Bcl-2和Caspase-3表达的影响.方法：建立卵巢癌SKOV3裸鼠移植瘤模型,将30只荷瘤鼠随机分为5组：空白对照组、白桦酯醇高、中、低浓度组和顺铂组（阳性对照）.21天后处死裸鼠,称取瘤重量,观察抑瘤率;免疫组织化学SP法检测移植瘤Bcl-2和Caspase-3的表达.结果：高、中、低组抑瘤率为54.19％、35.75％、20.67％,与空白对照组比较差异有统计学意义（P＜0.05）;高剂量组抑瘤率与顺铂组无差异（P＞0.05）.免疫组化显示,各治疗组Bcl-2的表达较空白对照组明显下调;Caspase-3的表达较空白组明显活化,其高剂量组表达与阳性药物顺铂相当.结论：白桦酯醇有一定的抑制卵巢癌生长的作用,可能与其诱导细胞凋亡有关.     

二烯丙基二硫对人胃癌细胞裸鼠移植瘤的抗肿瘤作用

背景与目的:既往研究发现二烯丙基二硫(diallyldisulfide,DADS)在体外可抑制多种肿瘤细胞生长,但在体内抗肿瘤作用的研究报道较少。本实验旨在探讨DADS对人胃癌细胞移植瘤在BALB/C裸鼠体内生长的影响。方法:未经药物处理和经30mg/LDADS处理1天的胃癌细胞MGC803接种于裸鼠皮下;观察体外DADS处理MGC803细胞裸鼠移植瘤的成瘤情况和未处理MGC803细胞移植瘤成瘤后腹腔注射DADS对胃癌移植瘤在BALB/c裸鼠体内生长情况的影响。Westernblot检测瘤组织中增殖细胞核抗原(proliferatingcellnuclearantigen,PCNA)的表达情况。结果:30mg/LDADS处理的MGC803细胞移植裸鼠体内无一成瘤。荷瘤裸鼠腹腔注射DADS剂量为50、100和200mg/kg时的抑瘤率分别为27.8%、66.1%和73.0%,同时可抑制移植瘤癌细胞PCNA的表达。结论:DADS可明显降低胃癌细胞裸鼠移植瘤的成瘤性,并对移植瘤生长有明显抑制作用。     

Antitumor effect of human leukocyte interferon on human osteosarcoma transplanted into nude mice

We studied the effect of human leukocyte interferon (HuIFN-α) on a human osteosarcoma (OS-OH) transplanted and passed serially in athymic mice. The growth of OS-OH was strikingly inhibited by HuIFN-α (50,000 IU/mouse), regardless of whether the interferon treatment was initiated 24 hr after tumor inoculation or 2 weeks later, when tumors had grown to an appreciable size (4–6 mm). The antitumor effect of HuIFN-α was found to be dose-dependent and a daily administration of HuIFN-α(50,000 IU/mouse) all but completely arrested the tumor growth.     

Intraperitoneal xenografts of human epithelial ovarian cancer in nude mice

Using continuous human ovarian cancer cell lines, i.p. xenografts were successfully established in nude mice from four of four attempts. When primary tumor material was used, xenografts grew in 8 of 10 attempts. From these eight, three passageable xenograft cell lines have been established. To our knowledge, this is the first report published of such xenografts. I.p. xenografts closely mimic the clinical behavior of human ovarian cancer, and those developed from primary tumor material maintain close morphological similarity to the parent primary tumor. When expression of placental alkaline phosphatase and the tumor associated antigens defined by the monoclonal antibodies HMFG1, HMFG2, AUA1, and F36/22 by these models was determined, those i.p. xenografts derived from primary tumor material exactly matched the original tumor, while none of the xenografts derived from the cell lines expressed these antigens. These models will be useful for investigating the biology and treatment of ovarian cancer.     

Conversion of 5'-deoxy-5-fluorouridine to 5-FU by pyrimidine nucleoside phosphorylases in normal and tumor tissues from rodents bearing tumors and cancer patients

Enzyme levels of pyrimidine nucleoside phosphorylase, which is an essential enzyme for the phosphorolysis of 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil (5-FU), in normal and tumor tissues were investigated. In all mouse strains tested, the enzyme level was found to be higher in the small intestine and stomach than other tissues, while in rats a higher level of the enzyme in the lung was also observed additionally. The enzyme levels of tumor tissues varied in tumor cell lines transplanted. P388 leukemia, Ehrlich ascites carcinoma, sarcoma 180, colon 26 carcinoma, and Lewis lung carcinoma cells contained high levels of the enzyme and the mice bearing these tumors responded well to the therapy with 5'-DFUR than its active metabolite 5-FU, while 5'-DFUR did not show clear advantage over 5-FU against L1210 or LSTRA leukemia, in which the enzyme levels were low. These results indicate that there is some correlation between the enzyme level and antitumor efficacy of 5'-DFUR. In human specimens, the enzyme levels were 2-6 times higher in tumors than those of the corresponding normal tissues and those adjacent to the tumors. These results predict that 5'-DFUR seemed to be converted efficiently to 5-FU also in human tumors.     

Efficacy of intra-hepatectomy 5-FU on recurrence and metastasis of human hepatocellular carcinoma in nude mice

A novel intra-operative chemotherapy nude mouse model for human hepatocellular carcinoma (HCC) has been developed. Intra-peritoneal (i.p.) administration of 5-fluorouracil (5-FU) was begun 2 hr before hepatic resection of HCC and then continued post-operatively for 4 consecutive days. This regime, termed intra-hepatectomy chemotherapy (IHC), significantly prolonged animal survival compared with pre-operative 5-FU, neoadjuvant therapy, 5-FU post-operative adjuvant therapy, surgery alone, 5-FU without surgery, and the untreated control. The median survival of the intra-operative 5-FU-treated group was 127 days compared with 78 days for the neoadjuvantly-treated animals and 53 days for the control group (p<0.006). When all animals with neoadjuvant 5-FU treatment had died, 60% of the animals in the IHC group were still alive (p<0.011). Survival of all other treatment groups, including 5-FU without surgery, surgery alone, and adjuvant post-operative chemotherapy, was not significantly different from the untreated control group. Five animals in the IHC group were free of tumor when sacrificed at day 150 post-surgically. While 100% of animals in the control group had lymph nodes draining the liver involved with metastases, only 20% of animals in the IHC group had lymph node metastases. These data suggested that IHC therapy increased survival by preventing metastases of cancer cells not removed in the liver resection procedure. The results of this study indicate that IHC therapy for resection of HCC should be investigated clinically.     

Antitumor effect of trimelamol against human breast carcinoma xenografts in nude mice

The antitumor effect of N-2, N-4, N-6-trihydroxymethyl-N-2, N-4, N-6-trimethylmelamine (trimelamol), a synthetic analogue of hexamethylmelamine, was investigated using human breast carcinoma xenografts in nude mice. Four tumor models, T-61, Br-10, R-27 and MCF-7 were estrogen receptor (ER)-positive and their growth was estradiol-dependent. The MX-1 model was ER-negative and grew estradiol-independently. Sixty mg of trimelamol per kg dissolved in 5% dimethylsulphoxide (DMSO) with 5% glucose was administered intraperitoneally for 5 days weekly for three weeks. Trimelamol showed potent antitumor activity on T-61 and MX-1 in a dose-responsive manner with a marginal effect on Br-10, whilst R-27 and MCF-7 were insensitive to this agent. This antitumor spectrum on human breast carcinoma xenografts was similar to that of hexamethylmelamine previously reported using the same xenograft models. Trimelamol is water-soluble and does not require metabolic activation which is needed for hexamethylmelamine. These advantages allow the paraenteral administration of trimelamol, and warrant the further investigation of this drug for breast carcinomas.