Induction of apoptosis in human tumour xenografts after oral administration of uracil and tegafur to nude mice bearing tumours

Effect of Tegafur-Uracil in Resected Stage IB Lung Adenocarcinoma According to Presence or Absence of Epidermal Growth Factor Receptor Gene Mutation: A Retrospective Cohort Study

PURPOSE

Tegafur-uracil (UFT) is the standard postoperative adjuvant therapy for stage IB lung adenocarcinoma (LUAD) in Japan. This study aimed to determine whether UFT is effective in stage IB LUAD with and without epidermal growth factor receptor (EGFR) mutations.

METHODS

This retrospective study included 169 patients with stage IB LUAD who underwent complete resection at our department between 2010 and 2021. We investigated the clinicopathological and prognostic impact of EGFR mutations as well as the postoperative use of UFT.

RESULTS

EGFR mutation-positive cases tended to show a higher cumulative recurrence rate than EGFR mutation-negative cases (p = 0.081), while overall survival was comparable between the groups (p = 0.238). In the entire cohort, UFT administration was not an independent prognostic factor in the multivariate regression analysis (p = 0.112). According to a stratification analysis, UFT administration was independently associated with favorable overall survival (p = 0.031) in EGFR mutation-negative cases, while it was not associated with recurrence-free survival (p = 0.991) or overall survival (p = 0.398) in EGFR mutation-positive cases.

CONCLUSION

UFT administration can improve the prognosis of EGFR mutation-negative LUAD but not EGFR mutation-positive LUAD. Thus, clinical trials of adjuvant-targeted therapy for EGFR mutation-positive stage IB LUAD should also be conducted in Japan.

Tumor mutation burden as a biomarker for lung cancer patients treated with pemetrexed and cisplatin (the JIPANG-TR)

The JIPANG study is a randomized phase III study of pemetrexed/cisplatin (Pem/Cis) versus vinorelbine/cisplatin (Vnr/Cis) for completely resected stage II-IIIA non-squamous non-small cell lung cancer (Ns-NSCLC). This study did not meet the primary endpoint (recurrence-free survival, RFS) but Pem/Cis had a similar efficacy to Vnr/Cis with a better tolerability. Tumor mutation burden (TMB) is thought to have a predictive value of immune checkpoint inhibitors. However, the relevance of TMB to cytotoxic chemotherapy remains unknown. This exploratory study investigates the relationship between tumor mutation profiles and clinical outcome of Pem/Cis. Formalin-fixed, paraffin-embedded tumor tissues (n = 389) were obtained from the patients. Mutation status of tissue DNA was analyzed by targeted deep sequencing. Epidermal growth factor receptor (EGFR) mutations were detected frequently in Ns-NSCLC (139/374). Patients without any EGFR mutations experienced longer RFS in the Pem/Cis arm versus Vnr/Cis arms. Pem/Cis in patients with high TMB (≥12-16 mut/Mb) tended to have improved survival. In patients with wild-type EGFR, TMB ≥ 12 mut/Mb was significantly associated with improved RFS with Pem/Cis versus Vnr/Cis (not reached vs 52.5 months; hazard ratio (HR) 0.477). It could be proposed that TMB was predictive of RFS benefit with Pem/Cis versus Vnr/Cis in Ns-NSCLC. Further investigation is required to determine whether TMB combined with EGFR mutation status could be used as a predictive biomarker.

Roles of microRNA let-7b in papillary thyroid carcinoma by regulating HMGA2

The incidence of thyroid cancer has increased significantly in the last decade, and the most frequent type of this cancer is papillary thyroid carcinoma. MicroRNAs have been demonstrated to be abnormally expressed in tumors and associated with the development of the tumors. Our aim was to analyze the role and molecular mechanisms of tumor suppressor let-7b in the papillary thyroid carcinoma. Expression of let-7b and high-mobility group A2 in papillary thyroid carcinoma tissues and cell lines was assessed using quantitative reverse transcription polymerase chain reaction and western blot analysis. To explore the role of let-7b or high-mobility group A2 in the BCPAP and TPC-1 cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell methods were used. Let-7b expression was significantly downregulated while expression of high-mobility group A2 was upregulated dramatically in papillary thyroid carcinoma tissues and cells compared with that in normal thyroid tissues and cells. In addition, overexpression of let-7b or knockdown of high-mobility group A2 inhibited cell migration and invasion compared with that of control. Besides, high-mobility group A2 was negatively regulated by let-7b in BCPAP cells. Moreover, high-mobility group A2 reintroduction reversed the anti-proliferation, anti-migration, and anti-invasion roles of let-7b. Let-7b might function as a tumor suppressor in papillary thyroid carcinoma by suppressing the expression of high-mobility group A2, and therefore might provide a promising therapeutic target for patients with papillary thyroid carcinoma.

Synergistic chemopreventive effects of nobiletin and atorvastatin on colon carcinogenesis

Different cancer chemopreventive agents may act synergistically and their combination may produce enhanced protective effects against carcinogenesis than each individual agent alone. Herein, we investigated the chemopreventive effects of nobiletin (NBT, a citrus polymethoxyflavone) and atorvastatin (ATST, a lipid-lowering drug) in colon cancer cells/macrophages and an azoxymethane (AOM)-induced colon carcinogenesis rat model. The results demonstrated that co-treatments of NBT/ATST produced enhanced growth inhibitory and anti-inflammatory effects on the colon cancer cells and macrophages, respectively. Isobologram analysis confirmed that these interactions between NBT and ATST were synergistic. NBT/ATST co-treatment also synergistically induced extensive cell cycle arrest and apoptosis in colon cancer cells. Oral administration of NBT (0.1%, w/w in diet) or ATST (0.04%, w/w in diet) significantly decreased colonic tumor incidence and multiplicity in AOM-treated rats. Most importantly, co-treatment of NBT/ATST at their half doses (0.05% NBT + 0.02% ATST, w/w in diet) resulted in even stronger inhibitory effects on colonic tumor incidence and multiplicity than did NBT or ATST alone at higher doses. Statistical analysis confirmed that the enhanced chemopreventive activities against colon carcinogenesis in rats by the NBT/ATST combination were highly synergistic. Our results further demonstrated that NBT/ATST co-treatment profoundly modulated key cellular signaling regulators associated with inflammation, cell proliferation, cell cycle progression, apoptosis, angiogenesis and metastasis in the colon of AOM-treated rats. In conclusion, for the first time, our results demonstrated a strong synergy in inhibiting colon carcinogenesis produced by the co-treatment of NBT and ATST, which provided a scientific basis for using NBT in combination with ATST for colon cancer chemoprevention in humans.

Chemopreventive effects of nobiletin and its colonic metabolites on colon carcinogenesis

SCOPE

Nobiletin (NBT) is a major citrus flavonoid with various health benefits. Herein, we investigated the colon cancer chemopreventive effects of NBT and its colonic metabolites in a colitis-associated colon carcinogenesis mouse model as well as in human colon cancer cell models.

METHODS AND RESULTS

In azoxymethane/dextran sulfate sodium treated mice, oral administration of NBT effectively decreased both incidence and multiplicity of colonic tumors. NBT showed significant antiproliferative, proapoptotic, and anti-inflammatory effects in the mouse colon. HPLC analysis revealed that oral administration of NBT resulted in high levels of metabolites, i.e. 3'-demethylnobiletin (M1), 4'-demethylnobiletin (M2), and 3',4'-didemethylnobiletin (M3) in the colonic mucosa. In contrast, the colonic level of NBT was about 20-fold lower than the total colonic level of three metabolites. Cell culture studies demonstrated that the colonic metabolites of NBT significantly inhibited the growth of human colon cancer cells, caused cell-cycle arrest, induced apoptosis, and profoundly modulated signaling proteins related with cell proliferation and cell death. All of these effects were much stronger than those produced by NBT alone.

CONCLUSION

Our results demonstrated that oral administration of NBT significantly inhibited colitis-associated colon carcinogenesis in mice, and this chemopreventive effect was strongly associated with its colonic metabolites.

Potent anti-cancer effects of citrus peel flavonoids in human prostate xenograft tumors

Prostate cancer is one of the most prevalent malignancies and is the second leading cause of cancer-related deaths in men. Fruit and vegetable consumption is a novel, non-toxic therapeutic approach that can be used to prevent and treat prostate cancer. Citrus peels and their extracts have been reported to have potent pharmacological activities and health benefits due to the abundance of flavonoids in citrus fruits, particularly in the peels. Our previous studies demonstrated that oral administration of Gold Lotion (GL), an extract of multiple varieties of citrus peels containing abundant flavonoids, including a large percentage of polymethoxyflavones (PMFs), effectively suppressed azoxymethane (AOM)-induced colonic tumorigenesis. However, the efficacy of GL against prostate cancer has not yet been investigated. Here, we explored the anti-tumor effects of GL using a human prostate tumor xenograft mouse model. Our data demonstrated that treatment with GL by both intraperitoneal (i.p.) injection and oral administration dramatically reduced both the weights (57%-100% inhibition) and volumes (78%-94% inhibition) of the tumors without any observed toxicity. These inhibitory effects were accompanied by mechanistic down-regulation of the protein levels of inflammatory enzymes (inducible nitric oxide synthase, iNOS and cyclooxygenase-2, COX-2), metastasis (matrix metallopeptidase-2, MMP-2 and MMP-9), angiogenesis (vascular endothelial growth factor, VEGF), and proliferative molecules, as well as by the induction of apoptosis in prostate tumors. Our findings suggest that GL is an effective anti-cancer agent that may potentially serve as a novel therapeutic option for prostate cancer treatment.

P27/Kip1 is responsible for magnolol-induced U373 apoptosis in vitro and in vivo

Previously, we demonstrated that magnolol, a hydroxylated biphenyl compound isolated from the bark of Magnolia officinalis, at low concentrations (3-10 μM) exerted an antiproliferation effect in colon cancer, hepatoma, and glioblastoma (U373) cell lines through upregulation of the p21/Cip1 protein. Magnolol at a higher concentration of 100 μM, however, induced apoptosis and upregulated p27/Kip1 expression in U373. In the present study, we further studied whether the increased p27/Kip1 expression contributes to the magnolol-induced apoptosis in U373. Our data show that knock-down of p27/Kip1 expression significantly suppressed the magnolol-induced apoptosis, suggesting that p27/Kip1 might play an important role in the regulation of magnolol-induced apoptosis. This notion was further supported by demonstrating that magnolol induced an increase of the caspase activity in U373 in vitro and in vivo, and these effects were abolished by pretransfection of the cell with p27/Kip1 siRNA. To delineate the possible signaling pathways involved in the magnolol-induced increases of p27/Kip1 expression and apoptosis, we found that magnolol (100 μM) increased the levels of phosphorylated cSrc (p-cSrc), p-ERK, p-p38 MAP kinase (p-p38 MAPK), and p-AKT but not p-JNK in U373. Moreover, pretreatment of U373 with a cSrc inhibitor (PP2), a PI3K inhibitor (LY294002), an ERK inhibitor (PD98059), or a p38 MAPK inhibitor (SB203580) but not a JNK inhibitor (SP600125) significantly reduced the magnolol-induced increases of p27/Kip1 protein levels and apoptosis. Taken together, our data suggest that magnolol at a higher concentration of 100 μM induced apopotosis in U373 cells through cSrc-mediated upregulation of p27/Kip1.

In vivo antitumor effects of 4,7-dimethoxy-5-methyl-1,3-benzodioxole isolated from the fruiting body of Antrodia camphorata through activation of the p53-mediated p27/Kip1 signaling pathway

In this study, 4,7-dimethoxy-5-methyl-1,3-benzodioxole (SY-1) was isolated from three different sources of dried Antrodia camphorata (AC) fruiting bodies. AC is a medicinal mushroom that grows on the inner heartwood wall of Cinnamomum kanehirai Hay (Lauraceae), which is an endemic species that is used in Chinese medicine for its antitumor properties. We demonstrated that SY-1 [given as a 1-30 mg/kg body weight intraperitoneal (ip) injection three times per week] profoundly decreased the growth of COLO-205 human colon cancer cell tumor xenografts in an athymic nude mouse model. We further demonstrated that significant AC extract-mediated antitumor effects were observed at the highest concentration (5 g/kg body weight/day). No gross toxicity signs were observed (i.e., body weight changes, general appearance, or individual organ effects). Frozen COLO-205 xenograft tumors were pulverized in liquid N(2), and the expression of cell cycle regulatory proteins was detected by immunoblotting. We found that the p53-mediated p27/Kip1 protein was significantly induced in the low-dose (1 mg/kg body weight) SY-1-treated tumors, whereas the p21/Cip1 protein levels did not change. The G0/G1 phase cell cycle regulators induced by SY-1 were also associated with a significant decrease in cyclins D1, D3, and A. These results provide further evidence that SY-1 may have significance for cancer chemotherapy.

Pretreatment with an ethanolic extract of Taiwanofungus camphoratus (Antrodia camphorata) enhances the cytotoxic effects of amphotericin B

Taiwanofungus camphoratus, a well-known Chinese medicine used in Taiwan, possesses several pharmacological functions, including anticancer effects. In the present study, we aimed to investigate a novel anticancer effect by pretreating cancer cells with an ethanolic extract of T. camphoratus (TCEE) followed by the administration of an antifungal agent amphotericin B (AmB). Both TCEE and AmB showed significant dose-dependent cytotoxicity in HT29 cells. Pretreatment with a nontoxic dose of TCEE enhanced the cytotoxicity of AmB. Furthermore, significant apoptotic cell death was found in cells treated with TCEE and AmB. A combination treatment with AmB plus TCEE resulted in a significant repression of tumor growth in HT29 xenografts. Collectively, our results indicated that combined treatment with AmB and TCEE effectively induced apoptosis and inhibited tumor growth. In the future, TCEE may serve as a potential complementary and alternative medicine to treat patients suffering from colorectal cancer.

Epidermal Growth Factor Receptor Mutation Status and Adjuvant Chemotherapy With Uracil-Tegafur for Adenocarcinoma of the Lung

Purpose

Adjuvant chemotherapy with uracil-tegafur has been demonstrated to prolong survival among patients with resected lung adenocarcinomas. Epidermal growth factor receptor (EGFR) mutations have been reported to be present in lung adenocarcinomas. The present study evaluated whether the EGFR status could be used as a biologic predictor of the outcome of adjuvant chemotherapy with uracil-tegafur.

Patients and Methods

The EGFR mutational status of 187 patients with resected lung adenocarcinomas was determined using a polymerase chain reaction–based assay for EGFR exons 19 and 21; the results were then correlated with the effect of adjuvant uracil-tegafur chemotherapy on survival. The antiproliferative effect of fluorouracil (FU) on adenocarcinoma cell lines with EGFR wild-type or mutant type status was examined by measuring the inhibitory concentrations at 50% (IC50s).

Results

Among the 187 patients, 68 received uracil-tegafur as adjuvant chemotherapy, and 119 were not treated with any chemotherapeutic agents. EGFR mutations were present in 79 patients (43%). Overall, the adjuvant chemotherapy with uracil-tegafur significantly prolonged survival compared with the control group (hazard ratio = 0.38; P = .005). The survival benefit of adjuvant chemotherapy with uracil-tegafur was also examined after stratifying the patients according to EGFR mutation status. Adjuvant chemotherapy significantly prolonged survival among patients with EGFR wild-type tumors (hazard ratio = 0.34; P = .013) but not among patients with EGFR mutant tumors. In an in vitro experiment, the IC50s of EGFR mutant cells to FU were higher than those of wild-type cells, indicating that EGFR wild-type cells are more sensitive to FU than mutant cells.

Conclusion

EGFR status influenced the effect of adjuvant chemotherapy with uracil-tegafur. Adjuvant chemotherapy could be customized based on EGFR status.

Amrubicin, a novel 9-aminoanthracycline, enhances the antitumor activity of chemotherapeutic agents against human cancer cells in vitro and in vivo

Amrubicin, a completely synthetic 9-aminoanthracycline derivative, is an active agent in the treatment of untreated extensive disease-small-cell lung cancer and advanced non-small-cell lung cancer. Amrubicin administered intravenously at 25 mg/kg substantially prevented the growth of five of six human lung cancer xenografts established in athymic nude mice, confirming that amrubicin as a single agent was active in human lung tumors. To survey which antitumor agent available for clinical use produces a synergistic interaction with amrubicin, we examined the effects in combinations with amrubicinol, an active metabolite of amrubicin, of several chemotherapeutic agents in vitro using five human cancer cell lines using the combination index (CI) method of Chou and Talalay. Synergistic effects were obtained on the simultaneous use of amrubicinol with cisplatin, irinotecan, gefitinib and trastuzumab, with CI values after 3 days of exposure being <1. Additive effect was observed with the combination containing vinorelbine with CI values indistinguishable from 1, while the combination of amrubicinol with gemcitabine was antagonistic. All combinations tested in vivo were well tolerated. The combinations of cisplatin, irinotecan, vinorelbine, trastuzumab, tegafur/uracil, and to a lesser extent, gemcitabine with amrubicin caused significant growth inhibition of human tumor xenografts without pronouncedly enhancing body weight loss, compared with treatment using amrubicin alone at the maximum tolerated dose. Growth inhibition of tumors by gefitinib was not antagonized by amrubicin. These results suggest that amrubicin appears to be a possible candidate for combined use with cisplatin, irinotecan, vinorelbine, gemcitabine, tegafur/uracil or trastuzumab.

Risk of recurrence after surgical resection of small-sized invasive lung adenocarcinoma

OBJECTIVE

It has been reported that small-sized invasive lung adenocarcinomas, i.e., those classified as type C through type F according to Noguchi's classification, may also recur even after complete resection. We evaluated the prognostic value of molecular biologic markers (apoptosis, Ki-67, p53, epidermal growth factor) and clinicopathological factors in patients with small-sized invasive lung adenocarcinomas.

METHODS

The clinical records of all patients who had had a peripheral adenocarcinoma surgically resected between 1996 and 2002, and histologically diagnosed as type C through type F according to Noguchi's classification were retrospectively reviewed. The apoptotic index (AI) was determined by the triphosphate biotin nick end-labeling method and the expression of Ki-67, aberrant p53 protein and epidermal growth factor receptor was determined by immunohistochemical staining.

RESULTS

Data from 28 patients who had been followed up for a mean period of 41.8 months (range: 16 to 89 months) were evaluated. During the follow-up period, recurrence was seen in 6 patients. The log-rank test showed that AI was a significant predictor of cancer recurrence. The 5-year disease-free survival rate of the 10 patients in the high AI group (AI > 0.3%) was 100%; while that of the 18 patients in the low AI group (AI < or = 0.3%) was 50.5% (p = 0.036). None of the other molecular biologic markers or clinicopathological factors were found to be a significant predictor of cancer recurrence.

CONCLUSION

Peripheral small-sized invasive lung adenocarcinomas with a low AI carry an increased risk of distant metastases, indicating that adjuvant chemotherapy after complete resection might be needed.

In vitro and in vivo studies of the anticancer action of terbinafine in human cancer cell lines: G0/G1 p53-associated cell cycle arrest

Terbinafine (TB) (Lamisil), a promising oral antifungal agent used worldwide, has been used in the treatment of superficial mycosis. In our study, we demonstrated that TB dose-dependently decreased cell number in various cultured human malignant cells. Flow cytometry analysis revealed that TB interrupts the cell cycle at the G0/G1 transition. The TB-induced cell cycle arrest in colon cancer cell line (COLO 205) occurred when the cyclin-dependent kinase (cdk) system was inhibited just as the levels of p53, p21/Cip1 and p27/Kip1 proteins were augmented. In the TB-treated COLO 205, the binding between p53 protein and p53 consensus binding site in p21/Cip1 promoter DNA probe was increased. Pretreatment of COLO 205 with p53-specific antisense oligodeoxynucleotide decreased the TB-induced elevations of p53 and p21/Cip1 proteins, which in turn led to arrest in the cell cycle at the G0/G1 phase. Moreover, in the p53 null cells, HL60, TB treatment did not induce cell cycle arrest. Taken together, these results suggest an involvement of the p53-associated signaling pathway in the TB-induced antiproliferation in COLO 205. We further examined whether administration of TB could affect the growth of tumors derived from human colon cancer cells in an in vivo setting. COLO 205 cells implanted subcutaneously in nude mice formed solid tumor; subsequent intraperitoneal injections of TB (50 mg/kg) led to obvious decline in tumor size, up to 50-60%. In these tumors, increases in the p21/Cip1, p27/Kip1 and p53 proteins and the occurrence of apoptosis were observed. Combined treatment with TB and nocodazole (ND), a clinically used anticancer agent, potentiated the apoptotic effect in COLO 205. These findings demonstrate for the first time that TB can inhibit the proliferation of tumor cells in vitro and in vivo.

Ketoconazole potentiates the antitumor effects of nocodazole: In vivo therapy for human tumor xenografts in nude mice

Our previous studies demonstrated that the oral antifungal agent ketoconazole (KT) induces apoptosis and G0/G1 phase cell cycle arrest in human cancer cell lines. In this study, we first demonstrated that KT (1 microM) potentiated the apoptotic effects of nocodazole (ND, 1 nM) in COLO 205 cancer cells. We further demonstrated the therapeutic efficacy of a combined treatment of KT (50 mg/kg/three times per week) and ND (5 mg/kg/three times per week) in vivo by treating athymic mice bearing COLO 205 tumor xenografts. The antitumor effects of ND were significantly potentiated by KT in mice after 6 wk of treatment. No gross signs of toxicity were observed in mice receiving these treatment regimens. The apoptotic cells were detected in a microscopic view of the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining and by observation of DNA fragmentation in KT + ND-treated tumor tissues. The levels of cell cycle regulatory proteins were determined by Western blot analysis. Treatment with KT inhibits tumor growth through elevation of p53, p21/CIP1, and p27/KIP1 as well as inhibition of cyclin D3 and cyclin-dependent kinase 4 protein expression. Immunohistochemical staining analysis showed that p53, p21/CIP1, and p27/KIP1 immunoreactivity were induced in the tumor tissues. To clarify the roles of the p21/CIP1 and p27/KIP1 protein expression involved in G(0)/G(1) arrest and/or apoptosis induced by a combined treatment with KT and ND, antisense oligodeoxynucleotides (ODNs) specific to p21/CIP1 and p27/KIP1 were used. Our results demonstrated that apoptotic phenomena, including BAX induction and cytochrome C released from mitochondria induced by KT + ND, were significantly attenuated by pretreatment the cells with the p27/KIP1-specific antisense ODNs. These results indicate that p27/KIP1 protein does indeed play a critical role in the KT + ND-induced apoptosis. Our study revealed the molecular mechanism of KT + ND in regression of the tumor growth. The apoptotic effects of KT in a great variety of cancer cells make it a very attractive agent for cancer chemotherapy.

Antitumor effects of miconazole on human colon carcinoma xenografts in nude mice through induction of apoptosis and G0/G1 cell cycle arrest

Miconazole (MIC), a promising oral antifungal agent, has been used worldwide in the treatment of superficial mycosis. In this study, we demonstrated that MIC dose dependently arrested various human cancer cells at the G0/G1 phase of the cell cycle. The protein levels of p53, p21/Cip1, and p27/Kip1 were significantly elevated by MIC treatment in COLO 205 cells. Electrophoretic mobility gel shift assays showed that the nuclear extracts of the MIC-treated COLO 205 cells exerted a significant binding between wild-type p53 and its consensus-binding site present in the p21/Cip1 promoter. These results suggested that the p53-associated signaling pathway is involved in the regulation of MIC-induced cancer cell growth arrest. By immunoblot analysis, we demonstrated that cyclin D3 and cyclin-dependent kinase-4 (CDK4) protein levels were inhibited by MIC treatment in the cancer cells. Significant therapeutic effect was further demonstrated in vivo by treating nude mice bearing COLO 205 tumor xenografts with MIC (50 mg/kg ip). The protein expression of p53 was significantly increased in MIC-treated tumor tissues by immunohistochemical staining and Western blotting analysis. DNA fragmentation and TUNEL assay were performed and demonstrated that apoptosis occurred in tumor tissues treated with MIC. Our study provides the novel mechanisms of antitumor effects of MIC and such results may have significant applications for cancer chemotherapy.

Griseofulvin potentiates antitumorigenesis effects of nocodazole through induction of apoptosis and G2/M cell cycle arrest in human colorectal cancer cells

In this study, we demonstrate that apoptosis and G2/M cell cycle arrest were easily induced by treatment with the oral-antifungal agent, griseofulvin (GF). The mechanisms of GF-induced G2/M arrest were characterized as (a) induction of abnormal mitotic spindle formation, (b) elevation of cyclin B1/cdc2 kinase activity and (c) down-regulation of myt-1 protein expression. On the other hand, caspase 3 activation, Bcl-2 hyperphosphorylation and inhibition of the normal function of Bcl-2 associated with Bax were demonstrated to be the mechanisms of GF-induced apoptosis. DNA fragmentation and flow cytometry analyses demonstrated that combined treatment of GF with the cancer chemotherapeutic agent, nocodazole (ND), strongly potentiates the apoptotic effect and arrest of the G2/M cell cycle in 5 types of human cancer cells, but not in normal human keratinocytes (#76 KhGH). The combined treatment of GF and ND triggered the polymerization of purified tubulin in HT 29 but not in #76 KhGH cells. To further confirm these observations, the therapeutic efficacy was further examined in vivo by treating athymic mice bearing COLO 205 tumor xenografts, with GF (50 mg/kg), ND (5 mg/kg) or GF + ND. Combined treatment of GF and ND significantly enhanced the effect of ND, and led to cessation of tumor growth. These results suggest that chemotherapeutic agents (such as ND) administered in the presence of GF might provide a novel therapy for colorectal cancer.

Complete disappearance of recurrent hepatocellular carcinoma with peritoneal dissemination and splenic metastasis: a unique clinical course after surgery

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare phenomenon. We report a case of complete disappearance of intrahepatic, peritoneal and splenic metastases in HCC after hepatectomy using treatment with tegafur and uracil (UFT). The effect of UFT alone was not likely to have caused the disappearance of this tumour because HCC recurrence advance markedly within 5 months of surgery despite oral administration of UFT. This case demonstrates a unique postoperative clinical course that suggests spontaneous regression of HCC. This is the first case of complete disappearance of unresectable HCC with peritoneal seeding and splenic metastasis.

Preoperative treatment with tegafur suppositories enhances apoptosis and reduces the intratumoral microvessel density of human colorectal carcinoma

BACKGROUND

This study examined the effect of tegafur, a depot of 5-fluorouracil, in human colorectal carcinomas in terms of apoptosis, cell proliferation, and expression of p53 gene and angiogenesis-related molecules.

METHODS

A total of 32 patients with colorectal carcinoma were divided into 2 groups; 20 patients received tegafur suppositories (TS) at 1 g/day for 14 days before surgery, and 12 patients did not receive any chemotherapy. Surgically removed specimens were examined immunohistochemically for Ki-67, CD34, p53, p21, Bax, vascular endothelial growth factor (VEGF), and thymidine phosphorylase (dThdPase). Apoptotic tumor cells were visualized by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxigenin nick-end labeling (TUNEL) procedure.

RESULTS

The mean percentage of apoptotic index (AI) was 6.9 +/- 1.2 in the 20 TS-treated tumors and 4.4 +/- 1.0 in the 12 nontreated tumors (P < 0.001). In contrast, the mean percentage of Ki-67 labeling index (KI) became significantly lower in the former group (P < 0.05). The frequency of p21 expression was significantly higher in the TS-treated group than in the nontreated group (P < 0.05), whereas no difference was detected in p53 and Bax expression between the two groups. The mean intratumoral microvessel density was 47.8 +/- 19.8 in the TS-treated tumors and 66.8 +/- 16.5 in the nontreated tumors (P < 0.01). The frequency of dThdPase expression, but not of VEGF expression, became significantly lower with the TS treatment. p53 expression did not correlate with AI, KI, IMV density, or the expression of VEGF, p21, or Bax, except for dThdPase, which was significantly higher in the 18 p53 positive tumors (P < 0.05).

CONCLUSIONS

Preoperative TS treatment enhances apoptosis and suppresses angiogenesis of colorectal carcinomas in a p53-independent manner.