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To investigate the characteristics of superficial type colorectal epithelial neoplasia (SN) (adenoma, SAd; adenocarcinoma, SCa; superficial-elevation type, E; superficial-depression type, D), the expression of Lewis y (Le(Y)), a marker of apoptosis, and the labeling index of proliferative cell nuclear antigen staining (PCNA-LI) in the intramucosal regions of 56 SN lesions were investigated. Expression of Le(Y) was observed in cytoplasm or cell membrane from the surface to deep within some tubules in SN lesions. Le(Y) was detected at higher rates in SCa lesions than in SAd lesions, in SCa lesions greater than 11 mm in diameter than in those less than 10 mm in diameter, in SCa-E lesions than in SCa-D lesions, in SCa lesions deeper than middle third of the submucosal layer, and was not related to size or macroscopical appearance of SAd lesions. PCNA-LI rate was higher in SCa lesions than in SAd lesions, in SCa lesions with carcinoma invasion to the submucosal layer than in SCa lesions with carcinoma invasion limited to the propria mucosa, and that of SAd lesions was inversely correlated with tumor size although that of SCa lesions was positively correlated with tumor size. There was a relationship between the high degree of expression of Le(Y) and PCNA-LI. In SCa lesions apoptosis and cell proliferation reflected that the enlargement and/or deeper invasion of carcinomatous tissue and in SAd lesions apoptosis had no relationship to tumor size although the cell proliferation inversely correlated with tumor size. This suggested that SCa-D lesions and the SCa-E with much higher proportions of apoptotic cells progressed to the ulcerative advanced cancer, and the size of many SAd lesions had a limit.

Autocrine motility factor (AMF) a tumor-secreted 55 kDa cytokine induces tumor cell motility by a signal transduction pathway mediated by interaction with its receptor (AMFR) a cell surface glycoprotein of 78 kDa (gp78). Here, AMF secreted by the metastatic LMF4 human oral squamous-cell carcinoma (SCC) cells, induced dose- and time-dependent morphological changes and chemotaxis of the producing cells. Expression of AMFR mRNA was associated with the metastatic ability of SCC cell variants. The data presented show for the first time that SCC cells produce AMF and express AMFR and the expression is related to their invasiveness and metastatic potentials.

The effects of a synthetic serine protease inhibitor, FOY-305, on the proliferation of normal and transformed mouse fibroblasts were investigated in vitro by MTT colorimetric assay. FOY-305 inhibited the growth of normal NIH3T3 cells and their src- and erbB2-transformed cells with a half maximum inhibitory concentration (IC50) of 1-1.2 mg/ml whereas it suppressed the growth of ras-transformed cells more effectively (IC50 was 0.5-0.6 mg/ml). Flow cytometric analysis using synchronized NIH3T3 cells has shown that the growth-inhibitory activity of FOY-305 was due to the suppression of G(1)/S transition. The synergistic effects between FOY-305 and traditional anticancer drugs were also investigated by the MTT assay and the results showed that FOY-305 significantly enhanced the antiproliferative activities of 5-fluorouracil (5-FU), 1-hexylcarbamoyl-5-fluorouracil (HCFU), 7-ethyl-1-hydroxy-7-ethyl-10-[4-(1-piperidino)-1-piperidino] camptothecin (SN-38), pirarubicin (THP) and 1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU).

To clarify the relationship between angiogenesis and the early development of colon cancer, expression of platelet-derived endothelial cell growth factor (PD-ECGF), a known angiogenic and endothelial cell chemotactic factor, was examined in 119 human colon premalignant adenomas and colon carcinomas. Localization of PD-ECGF was assessed by immunocytochemistry in 70 nonpolypoid growth (NPG) lesions that represented 29 carcinomas (NPG carcinomas) and 41 adenomas (NPG adenomas) and 49 polypoid growth (PC) lesions that included 15 carcinomas (PG carcinomas) and 34 adenomas (PC adenomas). Simultaneously, the expression of tranforming growth factor alpha (TGF alpha) and epidermal growth factor receptor (EGFR) were examined in serial sections from these lesions. Twenty (68.9%) of 29 NPC carcinomas and 20 (48.7%) of 41 NPC adenomas exhibited positive staining for PD-ECGF, whereas 15 (100%) of 15 PG carcinomas and 27 (79.4%) of 34 PG adenomas expressed PD-ECGF. There was a statistically significant difference in the frequency of PD-ECGF expression between NPG adenomas and PG adenomas (p<0.01). In addition, the incidence of PD-ECGF expression was higher in PG carcinomas than in NPG carcinomas (p<0.05). Positive staining for TGF alpha and EGFR was detected in 14 (48.2%) and 10 (34.5%) of 29 NPG carcinomas, respectively, whereas, 17 (41.5%) and 13 (31.7%) of 41 NPG adenomas expressed TGF alpha and EGFR, respectively. A significant trend for coexpression of PD-ECGF and TGF alpha was detected in either NPG adenomas (p<0.05) or PG adenomas (p<0.01). These data demonstrate that PD-ECGF may be involved in the early stages of colon cancer development during the adenoma-carcinoma transition and additionally that angiogenesis which may be induced by PD-ECGF and/or TGF alpha could play an important role of colon cancer development.

Histone deacetylase inhibitors such as sodium butyrate or (R)-trichostatin A {(R)-TSA; 7- [4-(dimethylamino) phenyl]-N-hydroxy-4,6-dimethyl-7-oxo-2, 4-heptadienamide} have been reported to modulate the proliferation and differentiation of certain cell types. In this study, we analyzed the effects of these agents on KM12 human colon carcinoma (HCC) cells in culture. We found that (R)-TSA induced cell flattening, inhibited anchorage-dependent and anchorage-independent growth, increased the level of the differentiation marker carcinoembryonic antigen, and increased the expression of gelsolin, a candidate tumor suppressor, in these HCC cells. Cells treated with (R)-TSA for 3 h exhibited a high degree of histone (primarily H4) acetylation. (R)-TSA exerted these effects at concentrations in the range between 0.1 to 1 mu M that are at least 1,000 times lower than those required to achieve similar effects by n-butyrate. Trichostatin C, which exhibits some histone deacetylase inhibitory activity but not the analogs (S)-TSA or (R)- or (S)-trichostatic acid, which lack histone deacetylase inhibitory activity, also showed some growth inhibitory activity. These results indicate that histone deacetylase inhibitors may lead to suppression of the transformed phenotype and enhanced differentiation in the KM12 HCC cells.

The efficiency of gene transfer into human cancer cells from digestive tract was evaluated using a replication-deficient recombinant adenovirus (Ad) vector harboring a lacZ gene of E. coli as a reporter gene (AxCALacZ). Average percent X-gal staining of esophageal cancer cell lines was 46%, that of gastric cancer cell lines 82% and that of colon cancer cell lines 70% at 3 days after Ad vector infection. X-gal staining in vitro continued 2 months after infection. By the direct injection of adenovirus vector to the tumors in nude mice, a certain percentage of tumor cells was stained by the X-gal. Colon26 cell line infected with AxCALacZ was implanted in BALB/c mice immunized with AxCALacZ, and tumor growth was suppressed. We presume this was due to anti-adenoviral immunity.

To reveal the signaling pathway leading to oncogenecity of human cancer cells, we examined the expression and tyrosine-phosphorylation of phosphatidylinositol (PI)-3 kinase in cancer cell lines. Of the 14 cell lines examined, two poorly differentiated human gastric cancer cell lines, NUGC-4 and MKN-45, which were previously found to have aberrant elevation of tyrosine phosphorylation showed elevated levels of PI-3 kinase 85-kDa subunit expression. In these cells, tyrosine-phosphorylation and overall activity of PI-3 kinase were apparently elevated, compared with normal human fibroblasts and another well differentiated gastric cancer cell line, MKN-28. Treatment of these cells with tyrosine kinase inhibitor, genistein, strongly suppressed the PI-3 kinase activity. Furthermore, wortmannin, a potent inhibitor of PI-3 kinase, strongly suppressed the growth of these gastric cancer cells. These results suggest that the growth signaling via tyrosine phosphorylation is required for the activation of PI-3 kinase in NUGC4 and MKN-45, and that this activation plays an important role in oncogenic growth of these cells. However, these two cell lines showed different responses of PI-3 kinase to acid-treatment and tyrosine kinase inhibitors. In MKN-45, activation of PI-3 kinase appeared to be constitutive, and could be relevant to the oncogenic nature of the cell line.

The effects of retinoic acid (RA) analogues, Am80 and Ch55, on acute myeloblastic leukemia (AML) cells, acute promyelocytic leukemia (APL) cells, and normal bone marrow (BM) cells, were studied in vitro. These analogues have different binding affinity to RA receptors and cellular retinoic acid binding proteins (CRABP). All-trans RA (ATRA) showed various effects on the proliferation of AML cells and BM cells. These analogues showed similar effects. Regarding the differentiation of APL cells into neutrophils, Ch55 and Am80 were more potent than ATRA. Ch55, which does not bind to CRABP, may overcome the clinical problem of retinoid-resistance due to the induction of CRABP.

Expression of src related proto-oncogenes in non-Hodgkin's lymphomas and non-malignant lymph nodes was analyzed by means of in situ hybridization assays with biotinylated DNA probes. In 36 cases of non-Hodgkin's lymphomas, both c-mos and c-abl were expressed in 27 cases, and c-erbB and c-src were expressed in 15 cases and 7 cases, respectively. No case expressed c-fps or c-yes. On the contrary, in 11 cases of non-malignant lymph nodes c-erbB and c-mos was expressed in only 3 cases. No other proto-oncogenes were expressed. Lymphomas in general express multiple proto-oncogenes simultaneously. A variety of combinations of expressed proto-oncogenes were observed suggesting diversity among non-Hodgkin's lymphomas in biological characteristics. However, a clear association with the expression of a single proto-oncogene or the number of expressed proto-oncogenes with T cell / B cell types, or the histopathological classification of NHL, or disease prognosis was not observed.