p53 expression overcomes p21WAF1/CIP1-mediated G1 arrest and induces apoptosis in human cancer cells.

The p21WAF1/CIP1 gene, which encodes a cyclin-dependent kinase inhibitor, may be critical for tumor suppressor gene p53-induced cell cycle arrest. The p53 gene is known to regulate G1 checkpoint, which can either induce G1 arrest or initiate apoptosis. To directly examine the role of p21WAF1/CIP1 in the control of p53 function, we have introduced human p21WAF1/CIP1 gene into a p53-deficient human non-small cell lung cancer cell line H1299 using a p21WAF1/CIP1-expressing adenoviral vector (AdCMVp21). Infection with AdCMVp21 resulted in high levels of p21WAF1/CIP1 expression and significantly suppressed the growth of H1299 cells through the G1 arrest of the cell cycle. In contrast, transient expression of the wild-type p53 gene by a recombinant adenoviral vector (AdCMVp53) in H1299 cells induced apoptotic cell death and resulted in a rapid loss of cell viability. We then examined the effects of combined infection with AdCMVp21 and AdCMVp53 on H1299 cells to explore the dominant function of these molecules. Interestingly, introduction of exogenous p53 overcame p21WAF1/CIP1-mediated cell cycle arrest at G1 and induced apoptosis, although viral-transduced p21WAF1/CIP1 expression level was unaffected. These observations suggest that p53 expression converts a p21WAF1/CIP1-mediated growth arrest into apoptosis. The result was repeated with two additional human colon adenocarcinoma cell lines with the different p53 status, mutant p53-expressing DLD-1 and wild-type p53-expressing LoVo, suggesting that this phemonenon is a general event among human cancer cells. Thus, p53-mediated apoptotic pathway is dominant over the growth arrest pathway, indicating that p53 may be an essential upstream mediator of p21WAF1/CIP1 in the regulation of a cell process leading either to growth arrest or to apoptotic suicide.

Differential involvement of the CD95 (Fas/APO-1) receptor/ligand system on apoptosis induced by the wild-type p53 gene transfer in human cancer cells.

The CD95 (Fas/APO-1) system regulates a number of physiological and pathological processes of cell death. The ligand for CD95 induces apoptosis in sensitive target cells by interacting with a transmembrane cell surface CD95 receptor. We previously reported that the recombinant adenovirus-mediated transfer of the wild-type p53 gene caused apoptotic cell death in a variety of human cancer cells. To better understand the mechanism responsible for this cell death signaling, we have investigated the potential involvement of the CD95 receptor/ligand system in p53-mediated apoptosis. The transient expression of the wild-type p53 gene upregulated the CD95 ligand mRNA as well as protein expression in H1299 human lung cancer cells deficient for p53 and in DLD-1 and SW620 human colon cancer cells with mutated p53, all of which constitutively expressed CD95 receptor as shown by a flow cytometric analysis, and induced rapid apoptotic cell death as early as 24 h after gene transfer. However, the sensitivity to the cytolytic effect of agonistic anti-CD95 antibody (CH11) varied among these cell lines: CH11 induced apoptosis in H1299 cells, but not in DLD-1 and SW620 cells despite their abundant CD95 receptor expression, suggesting that the CD95 receptors on DLD-1 and SW620 cells might be inactivated. In addition, an antagonistic anti-CD95 ligand antibody (4H9) that interfered with the CD95-receptor-ligand interaction partially reduced the apoptosis induced by the wild-type p53 gene transfer in H1299 cells, whereas apoptosis of DLD-1 and SW620 cells occurred in the presence of 4H9. Taken together, these findings led us to conclude that the CD95 receptor/ligand system is differentially involved in p53-mediated apoptosis, suggesting that the restoration of the wild-type p53 function may mediate apoptosis through CD95 receptor/ligand interactions as well as an alternative pathway.

Recombinant adenovirus expressing wild-type p53 is antiangiogenic: a proposed mechanism for bystander effect.

Angiogenesis is required for the growth and progression of malignancies. Recent studies have demonstrated that genetic alterations may accompany acquisition of the angiogenic phenotype. The tumor suppressor gene p53 is most frequently mutated in human cancers and is also known to be a transcriptional regulator of a variety of genes. Here, we investigated the antiangiogenic effect of the wild-type p53 (wt-p53) gene transfer on a human non-small cell lung cancer cell line. Mutant p53-expressing H226Br non-small cell lung cancer cells were transduced with the wt-p53 gene using a recombinant adenoviral vector (Ad5CMVp53) and applied to semiquantitative reverse transcription-PCRs for the detection of altered mRNA expression of angiogenic and/or antiangiogenic factors. In vivo neovascularization assay of Ad5CMVp53-infected cells was then performed using a membrane-diffusion chamber system s.c. transplanted in nu/nu mice. We also evaluated the effect of Ad5CMVp53-infected H226Br cells on nontransduced tumor cells in vivo by s.c. inoculating mixture of cells into nu/nu mice. Ad5CMVp53 infection markedly inhibited the expression of an angiogenic factor, vascular endothelial growth factor, and increased the expression of a novel antiangiogenic factor, brain-specific angiogenesis inhibitor 1, resulting in reduced neovascularization in vivo. Mixing experiments showed that tumor cells transduced with the wt-p53 gene inhibited the in vivo tumor growth of adjacent nontransduced cells. Our data suggest that a recombinant adenovirus expressing the wt-p53 gene is antiangiogenic, which may explain, in part, the mechanism of the bystander effect induced by the wt-p53 gene transfer on adjacent tumor cells.

Flow cytometric analysis on perforin induction in peripheral blood mononuclear cells with interleukin-2 or OK-432.

Perforin is a protein present in the cytoplasmic granules of killer cells and is considered to be an important effector molecule. We assessed the perforin appearance via flow cytometry in human peripheral blood mononuclear cells stimulated in vitro for 3 days by recombinant interleukin-2 (rIL-2) or OK-432, a biological response modifier. The relationship between the lymphocyte subsets and perforin was investigated via two-color assay. CD4-positive cells had almost no perforin, and most of the CD16-positive cells did. Regarding the relationship with CD8, some of the bright positive cells (which were likely T cells) and most of the dull positive cells (likely NK cells) had perforin. Mean fluorescence was greatest in perforin-positive cells incubated with rIL-2, less in cells incubated with OK-432, and minimal in cells incubated in a medium without additives. Immunohistochemical staining with antiperforin antibody revealed that blast-transformed and enlarge cells were stained positively and that the intensity of staining of each cell alone was enhanced in cells incubated with OK-432 or rIL-2. If the fluorescence intensity of perforin-positive cells correlates with the amount of perforin in those cells, then the appearance of perforin was enhanced with OK-432, more enhanced with rIL-2, and consistent for cytotoxicity against K562 and Daudi cells. IL-2 was induced by OK-432, suggesting that the indirect effect of this IL-2 may play a role in OK-432-perforin induction. The results suggest that perforin may be an effector molecule in killer cells induced by rIL-2 or OK-432.

The p53 gene is a potent determinant of chemosensitivity and radiosensitivity in gastric and colorectal cancers.

We previously reported that introduction of the wild-type p53 gene into human cancer cells with deleted p53 enhanced apoptosis induced by chemotherapy [Fujiwara et al. (1994) Cancer Res 54:2287]. This suggests that p53 status could be a potent determinant of the therapeutic efficacy of DNA-damaging cancer therapy. We analyzed 24 patients with gastric or colorectal cancer for p53 mutations and apoptotic changes in surgical specimens. Out of 11 patients with gastric cancer, 3 were treated with chemotherapeutic drugs before resection; 5 of 13 patients with colorectal cancer had 30 Gy radiation prior to surgery. p53 mutations were detected in 4 cases of gastric cancer (36.4%) and in 6 cases of colorectal cancer (46.2%) by immunohistochemical staining. The preoperative DNA-damaging therapies increased the number of apoptotic cells in wild-type-p53-expressing tumors; tumors with mutant p53, however, significantly showed fewer apoptotic cells compared with those expressing wild-type p53. The p53-inducible WAF1/CIP1 protein was immunohistochemically observed in wild-type-p53-containing tumors, whereas mutant-p53-expressing tumors expressed no detectable WAF1/CIP1. Taken together, we conclude that p53 mutations are associated with the poor response of chemotherapy and radiotherapy.

Five primary cancers in one patient.

We report a 62-year-old man with five primary cancers. He underwent nephrectomy for a right renal cell carcinoma and removal of malignant meningioma and 6 years later was diagnosed as having a rectal cancer and hepatocellular carcinoma. He died of respiratory failure and a gastric cancer was found at autopsy.

Colorectal cancer after irradiation for cervical cancer--case reports.

Three patients with colorectal cancer after irradiation for cervical cancer are described. One patient had two colorectal cancers. Three of the four cancers in these patients were located in the rectum and one in the sigmoid colon; all were within the irradiation field. Microscopic radiation proctocolitis was observed in all specimens. The interval between irradiation and the diagnosis of colorectal cancer was 20-24 years. It is important to consider patients who have undergone pelvic irradiation as being in a high risk group for the development of colorectal cancer. Close and long-term surveillance may be useful in these patients.

Complete regression of advanced liposarcoma of the anterior chest wall with interferon-alpha and tumor necrosis factor-alpha.

This paper reports a case of complete regression of a liposarcoma in a 62-year-old Japanese man who, in August 1986, presented with a giant subcutaneous tumor of the right anterior chest wall. Local radiotherapy and conventional chemotherapy were initially performed; however, the tumor did not respond at all. He then received cytokine treatment (interferon-alpha and tumor necrosis factor-alpha). Nineteen months after cytokine treatment, the mass disappeared totally. The patient has been in complete remission for five years without recurrence and with no additional treatment. This suggests that the use of interferon-alpha and tumor necrosis factor-alpha in combination may be an effective and promising modality for liposarcomas which are refractory to the conventional anticancer treatments.

Metachronous liver metastasis of colorectal cancer: timing of occurrence and efficacy of adjuvant portal chemotherapy.

We estimated the time of occurrence of metachronous liver metastasis in colorectal cancer patients from tumor diameter and doubling time. Micro-metastasis was present prior to operation in most patients and a few metastatic cases could have been initiated by the surgical procedure. Portal chemotherapy is more effective against liver metastasis than intravenous infusion because a higher drug concentration in the liver can be obtained. This efficacy of portal chemotherapy on survival was also observed in a rat model. Thus perioperative adjuvant treatment should be undertaken for metastasis which already existed before the operation and adjuvant chemotherapy via portal vein is the treatment of choice. The no touch isolation technique is also needed to avoid spreading of tumor cells during surgery.

Synchronous colorectal carcinomas.

Eighteen (5.0%) out of 358 patients who underwent resection of a colorectal carcinoma during the period 1978 through 1990 had synchronous colorectal carcinomas, and were 5.6 years younger on average than those with a single carcinoma. The distance between synchronous lesions was less than 10 cm in 69.6% of all the patients in the study. Among the synchronous carcinomas there was a higher incidence of ascending colon involvement, mucinous carcinoma, family history of malignant diseases, multiple malignant neoplasms associated with other organs and benign neoplastic polyps of the colorectum, and it is suggested that hereditary oncogenic factors influence these carcinomas. The synchronous lesions were detected pre-operatively in 14 of 18 patients with synchronous carcinomas, and the most common reason why synchronous lesions were missed was that the lesions on the anal side prevented the lesions on the proximal side from being examined. The prognosis in the synchronous lesion group was worse than in the solitary lesion group. Since it is difficult to predict synchronous colorectal carcinomas, careful pre-operative examination, including that of other organs, is necessary, and intra-operative colonoscopy should be carried out when pre-operative examination was insufficient.

Penile metastasis secondary to cecum carcinoma: a case report.

To date, only around 300 cases of metastasis to the penis have been reported and the primary cancer has been generally found in genitourinary structures. However, exceptional cases in which the primary site has been situated in organs like esophagus, pancreas, stomach have been published. We report an uncommon case in which the primary tumor was located in the cecum. To our knowledge, this is the first case of penile metastasis in which the responsible tumor was located in the cecum and in which the mode of metastasis was not direct invasion. As the tumor was restricted to the colon wall without invasion to neighbouring structures, and because colon cancer follows mainly the lymph-vascular route to its dissemination, this route is the most likely mode of the spread. By magnetic resonance imaging (MRI) on penile shaft, multiple nodules were clearly visualized. Nevertheless, as in most cases, in spite of the availability of advanced and precise diagnostic methods, the information was of little value for the patient. His survival was short.

Concomitant presence of anti-tumor effector cells and suppressor cells in the spleen of tumor-bearing mice : the nature of suppressor cells.

In order to investigate the immunological responsiveness of tumor-bearing hosts to tumor cells, splenic suppressor cells from Ehrlich tumor-bearing mice that inhibited anti-tumor effector cell activity were characterized. In vitro cell-mediated cytoxicity and cytostasis assays were performed to test for the existence of anti-tumor immunity. suppressive activity assayed by cell mixture experiments became apparent with decline of anti-tumor immunity and progressive tumor growth. The cells mediating the suppression were found to be nylon wool column adherent T cells and inhibited T cell dependent cytotoxicity rather than non-T cell dependent cytostasis. In vivo cell transfer experiments demonstrated that intravenous injection of suppressor cells to a host already inoculated with tumor cells mixed with antitumor effector cells resulted in significant enhancement of tumor growth. This inhibition of in vivo neutralization assay be suppressor cells was found in not only allogeneic but also syngeneic tumor system. Splenectomy at the time of tumor resection endowed the host with stronger resistance against subsequent reinoculated tumor than sham-splenectomy did, reflected by prolonged survival times. These results suggest that splenectomy combined with surgical removal of the tumor is a useful treatment of clinical malignancies.

Enhancement of experimental metastasis by gamma-interferon in a murine adenocarcinoma.

This study was conducted to examine the effect of gamma-interferon (IFN-gamma) on experimental metastasis formation by murine colon 26 adenocarcinoma in BALB/c mice. We found that the number of experimental lung metastases was increased after colon 26 cells were pretreated for 1 h with as little as 1 OIU/ml of IFN-gamma. 5-[125I] iodo-2'-deoxyuridine-radiolabeled colon 26 cells pretreated with IFN-gamma remained at higher level in the lung at 24h after intravenous injection than when the cells were not pretreated. In vivo elimination of asialo GM1-positive cells increased the number of lung metastases and, in such mice, there was no longer a difference in metastatic ability between control and IFN-gamma-treated cells. Colon 26 cells were completely resistant to lysis by isolated splenocytes. Splenocytes incubated in vitro with interleukin 2 exhibited moderate cytotoxicity against colon 26 cells, but there were no significant differences between control and IFN-gamma-treated cells. Colon 26 cells pretreated with IFN-gamma demonstrated resistance to tumor necrosis factor alpha-mediated growth inhibition. The enhancement of metastases by IFN-gamma was dependent on de novo protein synthesis since the enhancement was abolished by cycloheximide. Taken together, the data suggest that the metastatic ability of colon 26 cells pretreated with IFN-gamma is significantly higher due to the resistance to asialo GM1-positive cells accompanied with de novo protein synthesis.

The importance of family study in the patients with familial adenomatous polyposis.

Familial adenomatous polyposis (FAP) is a well-known autosomal dominant disorder characterized by the formation of multiple adenomatous polyps of the colon. Gardner's syndrome is a variant of familial polyposis coli, and both can be associated with colonic or extracolonic benign and/or malignant tumors. It has been widely recognized that an adenocarcinoma of the colon develops in virtually all cases, usually at an earlier age, if polyps are left untreated. Families of four individuals diagnosed of FAP were surveyed and 56 relatives of the families were examined. Of these 56, 21 had multiple colon polyps, 3 of whom had early-stage adenocarcinomas. We consider that familial survey of FAP individuals can be of considerable benefit for this high-risk population due to the autosomal nature of the disease, allowing diagnosis of an associated cancer at an earlier stage.

Therapeutic effect of neuraminidase-treated LAK cells on liver metastasis of Colon 26.

To improve the lymphokine-activated killer (LAK) cell therapy for liver metastasis, two methods which enhance accumulation of LAK cells in the liver were examined for their effects on the liver metastasis of Colon 26 cancer cells in BALB/c mice. Distribution of LAK cells in the mice was examined by the 51Cr labeling method. Portal vein infusion of LAK cells or tail vein infusion of neuraminidase treated-LAK (N-LAK) cells showed an augmented accumulation of infused cells in the liver. In the first experiment, LAK cells (5 x 10(7) cells) were infused in the portal vein or tail vein at days 3 and 7 after the inoculation of 5 x 10(4) tumor cells and 1 x 10(4) units of IL-2 were given three times a day from day 3 to day 7. The portal infusion of LAK cells produced a greater reduction of liver metastases compared with the peripheral infusion. In the second experiment, 5 x 10(7) LAK cells or N-LAK cells were infused via the tail vein on days 1 and 3, and 1 x 10(4) units of IL-2 were given once a day from day 1 to day 5 after the inoculation of 1 x 10(4) tumor cells. The therapeutic effect of N-LAK cells was greater than non-treated LAK cells on the number of metastatic lesions and the survival time of mice. Since access to the human portal vein is difficult and risky in clinical situation, peripheral infusion of N-LAK cells is preferable.

Suppression of hepatic natural killer activity by liver metastasis of cancer and restoration of killer activity by oral administration of a Basidomycetes-derived polysaccharide, PSK.

PSK (Krestin) is a protein-bound polysaccharide with antitumor and immunomodulatory activity. In this study, the effects of the oral administration of PSK were investigated on the natural killer (NK) activity of liver-associated lymphocytes and their subfractions separated by density gradient centrifugation, in WKAH rats with liver metastasis of KDA hepatoma. PSK was administered orally, at a dose of 500 mg/kg once a day for 3 weeks. The NK activity of nonparenchymal liver cells (NPLC) and their subfractions, including large granular lymphocytes (LGL), was markedly augmented by this treatment. The effects of oral PSK were also examined in CDF1 mice with liver metastases of Colon 26 adenocarcinoma; the survival of tumor-bearing mice was prolonged and both metastatic foci and liver weight were decreased. These results suggest that PSK may be effective for the suppression of liver metastasis through activation of liver-associated NK cells.

Synergistic effect of tumor necrosis factor-alpha and interferon-alpha on the induction of apoptosis detected by BM-1/JIMRO: a new marker of apoptosis.

The effects of the combination of natural human tumor necrosis factor-alpha (nHuTNF-alpha) and natural human interferon-alpha (nHuIFN-alpha) on the induction of apoptosis were investigated by immunohistochemical analysis with BM-1/JIMRO monoclonal antibody in RPMI 4788 tumor cells. Few tumor cells in the control culture could spontaneously undergo apoptosis. The number of positive cells increased at 2 and 4 h after treatment with nHuTNF-alpha (1 x 10(5) U/ml) and nHulFN-alpha (1 x 10(5) IU/ml). This effect was clearly maintained from 8 h up to 72 h of culture. The number of apoptotic cells also greatly increased with doses, suggesting that the apoptosis induced by nHuTNF-alpha and nHuIFN-alpha in combination was dose-dependent. nHuTNF-alpha or nHuIFN-alpha alone could induce apoptosis, but the induction increased significantly when the two cytokines were combined. These findings indicate that by combining nHuTNF-alpha and nHuIFN-alpha apoptosis can be synergistically induced in RPMI 4788 tumor cells, and may have specific therapeutic implications for clinical treatments using these two cytokines.

Clinical value of soluble interleukin-2 receptor in infectious complications.

In this study, we investigated serum-soluble interleukin-2 receptor (sIL-2r) and neopterin (NPT) levels in five patients with severe postoperative infections. A total of 25 synchronous determinations of sIL-2r and NPT were performed. A marked increase in sIL-2r and NPT levels was observed, and the increase in sIL-2r was significantly correlated to that of NPT which is a marker of macrophage activity. These results suggest that macrophages are involved in the stimulation of sIL-2r release, representing a potentially negative biological effect. The results indicate that sIL-2r may be a useful indicator of the efficacy of antibiotics and of prognosis.

Assessment of lymph node metastasis and vessel invasion in early rectal cancer.

Thirteen patients with rectal carcinoma seen between December 1980 and December 1990 have been reviewed to determine the risk of lymph node metastasis and its implication for subsequent treatment. The mean age was 64 years (from 38 to 79; 9 males, 4 females). The site of the tumor was predominantly in the lower rectum (53.8 percent). The polypoid (I) and flat-elevated ulcerated (IIa + IIc) subtypes were detected in seven and six lesions, respectively. Sphincter-saving techniques were carried out in eight cases, and five cases required Miles' operation. Neither postoperative complications nor deaths were noted. The mean follow-up period was 57 months (6 to 133 months). No recurrence or distant metastasis was found during this follow-up. IIa + IIc subtype lesions with deep submucosal invasion at or beyond Smlc level were closely related with lymphatic and vascular invasion. Although this association was not necessarily accompanied by an increased number of involved lymph nodes, major surgical resection is suggested in such IIa + IIc cases due to an increased possibility for lymph node metastasis.

Combined therapy with interleukin 2 and indomethacin in mice inoculated with MH134 hepatoma.

The antitumor effects of indomethacin and interleukin 2 (IL-2) were studied in C3H/HeJ mice inoculated with MH134 hepatoma cells. Combined treatment with indomethacin and IL-2 augmented natural killer (NK) cells in mice with MH134-induced peritoneal carcinomatosis, and the survival of the treated mice was significantly longer than the non-treated mice. In animals with subcutaneous MH134 tumors, the combined therapy with indomethacin and IL-2 significantly suppressed tumor growth and induced complete regression of the tumor in three out of five mice. These results suggest that indomethacin and IL-2 therapy could be effective on human gastrointestinal cancer cells as well.