The association of metastasis with the expression of adhesion molecules in cell lines derived from human gastric cancer

Peritoneal dissemination and hepatic metastasis commonly occur after patients with gastric cancer have undergone surgery. The presence of metastasis after surgery is sure to affect the prognosis of patients with gastric cancer. We conducted in vitro and in vivo studies to assess the role of adhesion molecules in this process, using 2 cell lines derived from human gastric cancer. Although both cell lines expressed several adhesion molecules to varying degrees, NUGC-4 cells, which disseminated early after inoculation into the abdominal cavity of nude mice accompanied by the formation of bloody ascitic fluid, predominantly expressed CD44H. However, MKN74 cells, which demonstrated hematogenous metastasis in the liver after inoculation into the spleen of nude mice, strongly expressed the sialyl Lewis(x) antigen (s-Le(x)), but did not express CD44H at all. When the binding of both these cancer cells to human umbilical vein endothelial cells was examined it was found that MKN74 cells adhered more strongly than NUGC-4 cells. The adhesion of cancer cells to endothelial cells was inhibited by treatment with antibodies against s-Le(x) and E-selectin. In the liver metastasis model of nude mice, treatment with anti-s-Le(x) antibodies significantly inhibited the development of MKN74 cell liver metastasis, both in the number of tumor nodules and in liver weight. NUGC-4 cells adhered to monolayers of mesothelial cells more strongly than MKN74 cells. The adhesion of NUGC-4 cells to these cells was partially inhibited by antibodies either against CD44H or the beta 1 subunit of integrin, but was completely blocked by a combination of these 2 antibodies. These antibodies markedly inhibited the dissemination of NUGC-4 cells in the peritoneal cavity of nude mice, and prolonged their mean survival time. These findings suggest that s-Le(x) and E-selectin mediate the adhesion of gastric cancer cells to endothelial cells, and CD44H and beta 1 integrin play important roles in the initial attachment of gastric cancer cells to mesothelial cells. It is possible that compounds that interfere with the function of cell adhesion molecules may decrease the incidence of gastric cancer metastasis.

Expression of the multidrug resistance-associated protein (MRP) gene in urothelial carcinomas

The intrinsic or acquired resistance of urothelial cancer to chemotherapy is one major obstacle to successful treatment. Generally, the expression level of P-glycoprotein in urothelial cancer is low, so we accordingly investigated the expression of multidrug resistance-associated protein (MRP). We examined the expression of MRP mRNA by means of slot-blotting samples of 11 renal pelvic and/or ureteral tumors, 33 bladder tumors, one lung metastasis from a ureter tumor, 7 non-cancerous urothelia from patients with transitional-cell carcinoma (TCC) and one urothelium from a patient with renal-cell carcinoma (RCC). We also estimated, by Southern blotting, whether or not the MRP gene was amplified in clinical specimens that overexpressed MRP mRNA. MRP was detected immunohistochemically using a polyclonal antibody against MRP. In all, 5 of 11 renal pelvic and/or ureter tumors (45.5%), 17 of 33 bladder tumors (51.5%) and 4 of 7 non-cancerous urothelia of TCC patients (57.1%) expressed more than 2-fold the MRP mRNA levels of drug-sensitive human KB cells. There was no significant difference in the MRP mRNA level between primary and recurrent tumors. Low-grade urothelial carcinomas (G1 and G2 TCCs) expressed significantly higher levels of MRP mRNA than the high-grade G3 TCC. The MRP gene was not amplified in urothelial carcinomas, irrespective of their expression levels of MRP mRNA. Immunohistochemically, MRP was located mainly on the plasma membrane, but also detected on the cytoplasm of cancer cells. MRP may be one mechanism responsible for intrinsic drug resistance in low-grade urothelial cancer.

Causes of rectal incontinence after sphincter-preserving operations for rectal cancer

PURPOSE

Low anterior resection (LAR) is the treatment of choice for middle and high rectal tumors. Even though the rectal sphincter is preserved, some patients show a postoperative loss of rectal continence that may be recovered during follow-up. The purpose of this study was to collect clinical and manometric data before and after LAR to find possible explanations for incontinence.

METHODS

Seventeen continent patients with rectal tumors located 10 cm above the anal verge were selected. Manometry was performed before and three months after surgery and when stable frequency of bowel movement was achieved (mean, 7 months).

RESULTS

Immediately after the operations, 14 of 17 patients showed a certain degree of incontinence but recovered during follow-up; at the end of the study, only two patients reported minor soiling. Resting and squeeze pressures were moderately reduced after surgery and increased during the following six months without regaining preoperative levels. Rectoanal inhibitory reflex was present in 94.4 percent of patients before the operations and in 25 percent of them after surgery, but it was not associated with incontinence. Rectal sensation was significantly reduced, and its recovery was well correlated with decrease in the frequency of bowel movements.

CONCLUSIONS

After LAR, there is a reduction in rectal pressures, suggesting damage to sphincter muscle fibers or innervation. There is also a reduction in rectal sensation related to loss in reservoir capacity, all of which may contribute to incontinence.

Endogenous tumor necrosis factor inhibits the cytotoxicity of exogenous tumor necrosis factor and adriamycin in pancreatic carcinoma cells

Pancreatic carcinoma is one of the most devastating neoplasms with regard to its resistance to conventional therapy. In a previous report, we found that endogenous tumor necrosis factor (enTNF) exerts an intracellular protective effect against exogenous TNF- and Adriamycin (ADM)-induced cytotoxicity by scavenging oxygen free radicals (OFR) with induced manganous superoxide dismutase (MnSOD). We also know that glutathione S-transferase pi (GST-pi) and glutathione (GSH) also scavenge OFR. It remains unclear to what extent enTNF and MnSOD induced by enTNF regulate the sensitivity to ADM and exogenous TNF among different carcinoma cells. In this study, we examined the relationship between ADM and exogenous TNF sensitivity and en-TNF expression and MnSOD activity in four pancreatic carcinoma lines. We determined whether ADM and exogenous TNF sensitivity could be predicted by measuring enTNF expression and MnSOD activity in the carcinoma cells. The sensitivity to TNF and ADM varied with the cell lines, and TNF sensitivity correlated well with Adriamycin sensitivity. Moreover, enTNF expression and Mn-SOD activity correlated positively with resistance to ADM and exogenous TNF. When MIAPaCa-2 cells, which had the lowest enTNF expression and the highest sensitivity to exogenous TNF and ADM, were transfected with the nonsecretory-type human TNF gene (pTNF delta pro) to increase enTNF synthesis, their intracellular MnSOD activity and exogenous TNF and ADM resistance were increased. These findings suggest that MnSOD plays a critical role in scavenging OFR induced by ADM and exogenous TNF. enTNF is the most important factor that regulates the production of MnSOD. Therefore, it is plausible that inhibition of enTNF expression or MnSOD activity in pancreatic carcinoma would improve the efficacy of therapies for pancreatic carcinoma.

Adhesion molecules involved in pleural dissemination of esophageal cancer cells

Pleural dissemination is a common cause of recurrence after surgery of patients with esophageal cancer. Very little is known about the biochemical processes involved in the initial attachment of cancer cells to pleural mesothelial cells. The authors conducted in vitro and in vivo studies to assess the role of adhesion molecules in this process, using 2 cell lines derived from human esophageal cancer. TE-1 cells, which pronouncedly express CD44H, adhered to the monolayers of mesothelial cells more firmly than T.Tn cells. On the other hand, the adhesion of TE-I cells to mesothelial cells was markedly inhibited by antibodies to CD44H or the beta(1) integrin subunit, and more strongly blocked by using a combination of the two antibodies. These antibodies inhibited the dissemination of TE-1 cells in the pleural cavity of nude mice. The findings suggest that CD44 and integrin play important roles in the initial attachment of esophageal cancer cells to mesothelial cells.

Malignant lymphoma of the gastric stump developing 25 years after a distal gastrectomy for benign gastric disease: report of a case

We report herein the case of a 57-year-old man in whom malignant lymphoma originating in the gastric remnant was confirmed 25 years after a subtotal gastrectomy with Billroth II reconstruction had been performed for gastric ptosis. Gastroscopy revealed an ulcerated tumor on the fornix, and histologic examination of the endoscopic biopsy specimens demonstrated malignant lymphoma. Thus, total gastrectomy with splenectomy, pancreatectomy, and resection of the previously anastomosed jejunal stoma were performed. Histologic examination of the stomach remnant confirmed a diagnosis of B-cell lymphoma of the large-cell type. Although we were unable to study the surgical specimen from the initial operation, the possible relationship between pseudolymphoma and malignant lymphoma has been presented in the literature, which is reviewed following this case report.

Uptake is the rate-limiting step in the overall hepatic elimination of pravastatin at steady-state in rats

PURPOSE

Of the HMG-CoA reductase inhibitors, the hydrophilic pravastatin has been shown to exhibit relatively specific inhibition of cholesterol synthesis in the liver. As one of the reasons for this relatively specific pharmacological activity, we demonstrated that the tissue distribution of pravastatin is limited because of its high hydrophilicity, while hepatic uptake by active transport takes place at the liver surface via a multispecific anion transporter (M. Yamazaki et al., Am. J. Physiol., 264, G36-44, 1993). In this study, we examined the hepatic elimination of pravastatin at steady-state.

METHODS

After i.v. infusion, the plasma concentrations of pravastatin in both arterial and hepatic venous blood were measured.

RESULTS

The hepatic availability at steady-state exhibited a clear increase on increasing the infusion rate of pravastatin. The total hepatic elimination rate at steady-state exhibited Michaelis-Menten type saturation with the drug concentration in the capillary defined by typical mathematical models (i.e., well-stirred, parallel-tube and dispersion models), K(m) and Vmax values being comparable with those obtained from analysis of the initial uptake velocity using in vitro isolated hepatocytes.

CONCLUSIONS

These results indicate that overall hepatic intrinsic clearance of pravastatin at steady-state is regulated by the uptake process, followed by rapid metabolism and/or biliary excretion with minimal efflux to the circulating blood.

A human canalicular multispecific organic anion transporter (cMOAT) gene is overexpressed in cisplatin-resistant human cancer cell lines with decreased drug accumulation

By targeting the ATP binding conserved domain in three ATP binding cassette superfamily proteins (P-glycoprotein, multidrug resistance protein, and cystic fibrosis transmembrane regulator), we isolated the cDNA of a new ATP binding cassette superfamily that was specifically enhanced in a cisplatin-resistant human head and neck cancer KB cell line. A human clone homologous to rat canalicular multispecific organic anion transporter (cMOAT) was found and designated human cMOAT. Fluorescence in situ hybridization demonstrated the chromosomal locus of the gene on chromosome 10q24. The human cMOAT cDNA hybridized a 6.5-kb mRNA that was expressed 4- to 6-fold higher by three cisplatin-resistant cell lines derived from various human tumors exhibiting decreased drug accumulation. Human cMOAT may function as a cellular cisplatin transporter.

Characterization of the ATP-dependent LTC4 transporter in cisplatin-resistant human KB cells

An active efflux pump for cis-diamminedichloroplatinum(II) (cisplatin) has been identified in cisplatin-resistant KCP-4 cells isolated from human epidermoid carcinoma KB-3-1 cells. The adenosine triphosphate(ATP)-dependent transport of leukotriene C4 (LTC4), an endogenous substrate for the glutathione S-conjugate export pump(GS-X pump), has been found in membrane vesicles prepared from KCP-4 cells. Multidrug resistance-associated protein (MRP) has also been identified as an ATP-dependent LTC4 transporter. To examine whether the GS-X pump expressed in KCP-4 cells in MRP, we investigated the expression of MRP in KCP-4 cells and compared the LTC4 transporting activity of GS-X pump expressed in KCP-4 cells with that of MRP. The level of MRP gene expression in KCP-4 cells was low and similar to that in KB-3-1 cells. MRP was not detected in membrane vesicles prepared from KB-3-1 and KCP-4 cells by immunoblot analysis. The ATP-dependent transport of LTC4 in KCP-4 and C-A120 vesicles showed saturable kinetics with an apparent Km of 0.18 microM and 0.25 microM, respectively. [3H]LTC4 transport in KCP-4 vesicles was more inhibited by 2,4-dinitrophenyl-S-glutathione(DNP-SG), bis-(glutathionato)-platinum(II) (GS-platinum) complex and glutathione disulfide(GS-SG) and less by LTD4 compared with that in C-A120 vesicles. The character of the LTC4 transporter expressed in KCP-4 vesicles is similar but not identical to that of MRP. Our results suggest that a glutathione S-conjugate export pump which is different from MRP exists in cisplatin-resistant KCP-4 cells.

[Neoadjuvant chemotherapy in high-grade advanced gastric cancer with protracted infusional 5-fluorouracil and consecutive low-dose cisplatin]

Twenty-one evaluable patients with primary gastric cancer/local invasion, liver metastasis and peritoneal metastasis were entered in a pilot study of neoadjuvant chemotherapy that used continuous 24-hour infusion 5-FU, 330 mg/m2/day plus low dose CDDP, 6 mg/m2 daily by bolus infusion d1-5. This regimen was repeated for 4 weeks. The overall response rate was 52%, including one complete and ten partial responses. The response rate of differentiated adenocarcinomas was significantly higher than that of poorly differentiated adenocarcinomas. In 15 patients (71%), gastrectomy and lymphadenectomy could be done after this regimen. chemotherapy-induced downstaging from the initial clinical stage was pathologically found in 5 patients who underwent gastrectomy. Toxicity was primarily hematologic. Leukopenia and thrombocytopenia of grade 3 or 4 occurred in 19% and 14% of patients, respectively. The patients were able to take meals during therapy and preserved good quality of life. Median survival time was 11 months for the cancers with liver metastasis and five of the 8 locally advanced cancers are alive 11 months after the therapy. This therapy was effective for patients with high-grade advanced gastric cancer.

Preoperative embolization of gastric arteries for esophageal cancer

BACKGROUND

We developed a novel treatment of preoperative embolization therapy in an attempt to prevent anastomotic leakage after esophageal resection. We report the results of this new treatment.

METHODS

Preoperative embolization therapy (PET) was performed in 24 cases of esophageal carcinoma. The femoral artery was punctured, and celiac angiography was performed. The left gastric artery and splenic artery underwent embolization. The right gastric artery then underwent embolization at a site beyond the second or third branch to the gastric wall. With a laser flow meter the stomach tissue blood flow was measured before and after construction of the gastric tube, and the change in blood flow was compared.

RESULTS

The average decrease in gastric blood flow was 23% in patients with PET and 65% in patients without PET. Twenty-one (88%) of 24 cases maintained more than 50% tissue blood flow in patients with PET and in 1 (8%) of 12 in patients without PET (p < 0.001 by t test). No serious complications occurred.

CONCLUSIONS

Preoperative embolization therapy is a safe and uncomplicated technique, and tissue blood flow in the stomach was better preserved. This new technique is expected to reduce the frequency of anastomotic leakage after esophageal operation.

Clinicopathologic and prognostic significance of an angiogenic factor, thymidine phosphorylase, in human colorectal carcinoma

BACKGROUND

Platelet-derived endothelial cell growth factor (PD-ECGF) is known to promote the development of new blood vessels, which are fundamental to tumor growth and metastasis. We previously found that thymidine phosphorylase (dThdPase) and PD-ECGF are the same protein.

PURPOSE

We retrospectively examined the expression of dThdPase in primary colorectal carcinomas, its association with angiogenesis and clinicopathologic findings, and its prognostic value.

METHODS

Tissues were obtained from the tumors of 163 patients whose colorectal carcinomas were completely removed by surgery. Microvessels assessed by immunostaining endothelial cells for factor VIII were counted on a 400x field in the most active areas of neovascularization within the tumor. We purified the monoclonal antibody against dThdPase and studied the expression of dThdPase in the same serial sections used for the detection of factor VIII. Those who carried out microvessel counting and dThdPase expression assessment had no knowledge of clinicopathologic findings. The significance of dThdPase in the prognosis of patients with colorectal carcinomas was also examined in the survival analysis of mortality follow-up data covering the period between 1984 through 1991. Reported P values are from two-sided tests of statistical significance.

RESULTS

The mean microvessel count (+/- standard deviation) in dThdPase-positive colorectal carcinoma specimens (17.5 +/- 7.2) was higher (P < .001) than that in dThdPase-negative carcinoma specimens (9.3 +/- 5.5). The dThdPase positivity was in accordance with the microvessel count. dThdPase positivity showed highly significant statistical associations with tumor size, extent of invasion, lymph node metastasis, lymphatic invasion, and venous invasion. Cox regression analysis revealed that dThdPase expression was prognostic for poor disease outcome after adjustment for Dukes' stage and microvessel count.

CONCLUSIONS

These findings suggest that higher levels of dThdPase expression in colorectal carcinomas are associated with more extensive angiogenesis, poor clinical and laboratory findings, and unfavorable clinical outcome.

IMPLICATIONS

Inhibition of dThdPase in human colorectal carcinomas might improve prognosis for some patients.

Effect of phosphate ion on mildiomycin production by Streptoverticillium rimofaciens

Effect of inorganic phosphate and ammonium nitrogen on mildiomycin production by Streptoverticillium rimofaciens was investigated in culture with and without addition of ferrous ion. In the presence of ferrous ion, the suitable supply of inorganic phosphate increased the intracellular ATP, but that was not observed without ferrous ion addition. The intracellular ATP remarkably affected ammonium nitrogen assimilation and mildiomycin production, and its concentration in the ferrous-sufficient culture was about 2 approximately 3 times higher than that in the ferrous-deficient culture. The low concentration of intracellular ATP in the ferrous-deficient culture resulted in the reduction of ammonium nitrogen assimilation and mildiomycin biosynthesis. This phosphate ion effect on the intracellular ATP concentration was demonstrated only when ferrous ion was added into the medium. These suggest that mildiomycin biosynthesis is regulated through the concentration of intracellular ATP related to the ammonium nitrogen assimilation.

HPLC determination of carnitine and acylcarnitines in human plasma by means of fluorescence labeling using 2-(4-hydrazinocarbonylphenyl)-4,5-diphenylimidazole

Carnitine and acylcarnitines are important substances involved in the oxidation and metabolism of fatty acids. An HPLC method is presented for the quantitative analysis of these compounds. The method is based on the detection of fluorescent derivatives of carnitine and short- and medium-chain acylcarnitines labeled with 2-(4-hydrazinocarbonylphenyl)-4,5-diphenylimidazole (HCPI). The labeling of carnitine and acylcarnitines with HCPI was performed at room temperature for 1 h using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide as a condensing reagent. The analytes prepared using cation-exchange cartridges were separated on an octadecylsilyl silica gel (ODS) column by a gradient elution system of acetonitrile/Tris-HCI buffer and determined using a synthetic internal standard. Fluorescence detection was performed at 475 nm with excitation at 340 nm. The detection limits for carnitine, acetyl-, propionyl-, hexanoyl- and octanoylcarnitine ranged from 0.24 to 1.97 nmol per ml human plasma, at a signal-to-noise ratio of 3. The within-day and between-day precision of the assay for carnitine and acylcarnitines in plasma samples had relative standard deviations (RSDs) lower than 10.3%. The concentration of free carnitine, acylcarnitines and total carnitine in human plasma could be successfully determined by the proposed method.

Genetic differences between the pancytosolic and perinuclear forms of murine mortalin

To determine the genetic relation between the pancytosolic (uniformly distributed in cytoplasm-p66mot-1) and the perinuclear (p66mot-2) mortalin proteins found in normal and immortal mouse cells, respectively, we initiated the present study using PCR cloning, sequencing, and single nucleotide primer extension analyses. The results indicate that the difference between mot-1 and mot-2 at 2 bp in the open reading frame does not arise by mutations in the immortalized cells. Intriguingly, both mot-1 and mot-2 sequences were detected in genomic DNA from normal (CMEF) and immortal (RS-4) cells derived from the CD1-ICR mouse strain. We extended the analyses to four other strains of mouse and detected both mot-1 and mot-2 sequences in genomic DNA from the Balb/c mouse also. Swiss and C57BL/6 mice exhibited only mot-2 and the C3H He mouse only mot-1. Southern analyses on a mouse strain that showed the presence of only mot-2 (Swiss) and one that showed both mot-1 and mot-2 (CD1-ICR) by PCR revealed that there are structural differences between mot-1 and mot-2 loci. Furthermore, there appears to be a correlation between frequency of spontaneous immortalization of cultured mouse fibroblasts and the mot loci present in the mouse strain from which they were derived.

Effect of ferrous ion on mildiomycin production by Streptoverticillium rimofaciens

A specific regulatory effect of ferrous ion on a biosynthesis of mildiomycin by Streptoverticillium rimofaciens was investigated. The minimal concentration of ferrous ion necessary for the maximal production of mildiomycin was about 8 micrograms/ml. The physiological effects of ferrous ion on the mildiomycin production were examined in the media with and without the ferrous ion. Addition of ferrous ion to the culture medium increased both the mildiomycin production (10 times) and an assimilation of ammonium-nitrogen, activities of peptidase and protease.

Severe acute metabolic acidosis and Wernicke's encephalopathy following chemotherapy with 5-fluorouracil and cisplatin: case report and review of the literature

A 28-year-old woman with inoperable gastric carcinoma was given continuous infusion of 5-fluorouracil (5-FU) and low-dose cisplatin (CDDP) for 4 weeks while receiving intravenous hyperalimentation (IVH). Eleven days after her last treatment, she developed acute diplopia, deafness and gait ataxia, followed by severe confusion. She became markedly acidotic and hypotensive with a systolic blood pressure of 60 mmHg, necessitating intubation, dopamine treatment and hemodialysis for 7 h. She was also given thiamine. Thereafter, her blood pressure stabilized, the acidosis improved, and her deafness, diplopia, and confusion were resolved. This case suggests that FP (5-FU/CDDP) therapy toxicity, manifested as acute metabolic acidosis and Wernicke's encephalopathy, may be associated with IVH and thiamine deficiency.

The activity and expression of thymidine phosphorylase in human solid tumours

Thymidine phosphorylase (dThdPase) is identical to platelet-derived endothelial cell growth factor (PD-ECGF) and has angiogenic activity. Since dThdPase seems to have an important role in angiogenesis of tumours, we measured the activity and expression of dThdPase in various tumours and the adjacent non-neoplastic tissues. We assayed dThdPase activity by spectrophotometric means, and the expression of dThdPase was examined by immunoblotting and by immunohistochemical staining using a monoclonal antibody against dThdPase. In the oesophagus, stomach, colorectum, pancreas, and lung, dThdPase activity in carcinomas was significantly higher (P < 0.05) than that in the adjacent non-neoplastic tissues. The expression level of dThdPase detected by immunoblotting correlated well with the activity of dThdPase. In the oesophagus, stomach, colorectum, gall bladder, pancreas and lung, the proportion of dThdPase-positive tumours was significantly higher (P < 0.05 or 0.01) than that of the dThdPase-positive adjacent normal tissues. In oesophageal, gastric colorectal and lung carcinomas, the proportion of dThdPase positivity in advanced carcinomas was significantly higher (P < 0.01) than that in early carcinomas. Tumour-infiltrative macrophages or lymphocytes in the lymph node, alveolar macrophages and Kupffer cells expressed high levels of dThdPase. The results indicate that dThdPase activity and expression level in many tumours are higher than those in the adjacent non-neoplastic tissues, and that dThdPase may have an important role in the proliferation of these solid tumours.

Bone morphogenetic protein-12 and -13 inhibit terminal differentiation of myoblasts, but do not induce their differentiation into osteoblasts

Effects of bone morphogenetic protein (BMP)-12 and BMP-13, new members of the BMP family which belong to the transforming growth factor (TGF)-beta superfamily, on terminal differentiation of myoblasts were examined in C2C12 and L-6 myoblasts. When the myoblasts were cultured with BMP-12 or BMP-13, the expression of the myosin heavy chain and the formation of multinucleated myotubes mRNA in L-6 cells. The inhibitory effects of BMP-12 and BMP-13 on myogenic differentiation were similar to the effects of BMP-2, though their potencies were lower than BMP-2. Unlike BMP-2, neither BMP-12 nor BMP-13 induced alkaline phosphatase activity in C2C12 myoblasts. The differences in the biological activities of these new BMPs suggest that the intracellular signalling pathway used by BMP-12 and BMP-13 differs from that of BMP-2.

Expression of the multidrug-resistance-associated protein (MRP) gene in human colorectal, gastric and non-small-cell lung carcinomas

MRP has been identified as another multidrug-resistance (MDR) gene and may be involved in an alternative MDR mechanism in some solid tumors. We investigated the expression of MRP mRNA in multidrug-resistance KB sublines (KB-8-5, KB-C2, C-A40 and C-A120), human non-small-cell lung carcinomas (NSCLC), gastric and colorectal carcinomas, and compared it with that in drug-sensitive human KB cells. MRP gene expression was elevated in 8 of 9 (89%) squamous-cell carcinomas of the lung. Furthermore, MRP expression in 4 squamous-cell carcinomas (L13, 18, 19 and 20) was more than 3.6 times higher than in KB-3-1 cells, and the average MRP mRNA expression level of all squamous-cell carcinomas was significantly higher than that of adenocarcinoma of the lung and of colorectal and gastric carcinomas. These results suggested that the MRP is responsible, at least in part, for drug resistance in some squamous-cell carcinomas of the lung.

Immunohistochemical analysis of the poorly differentiated stomach adenocarcinoma with medullary growth pattern

Poorly differentiated gastric adenocarcinoma with medullary features (poor medullary) is distinguished by a propensity for hepatic metastasis. To classify it antigenically, we compared it to poorly differentiated adenocarcinoma with scirrhous growth pattern (poor scirrhous), well and moderately differentiated adenocarcinoma (differentiated adenocarcinoma), and normal gastric mucosa (foveolar and deep epithelium) using immunohistochemistry with antibodies against CEA, AFP, NSE, and Lewis-type antigens. Lewis(a) antigen was significantly associated with differentiated adenocarcinoma and foveolar epithelium, although Lewis(x) antigen was significantly expressed in poor medullary, poor scirrhous, and deep gland epithelium. From the viewpoint of expression of Lewis(a), there was no significant differentiation between poor medullary and differentiated adenocarcinoma, but it was definite between poor scirrhous and differentiated adenocarcinoma. Therefore, we conclude that in antigenic expression, poor medullary carcinoma is allied with differentiated adenocarcinoma rather than poorly differentiated scirrhous carcinoma.

Increased expression of integrins by heparin-binding EGF like growth factor in human esophageal cancer cells

The adhesion of cancer cells to vascular endothelium is an important step in the hematogenous metastasis of cancer. The authors investigated the alteration of integrin expression in human esophageal cancer cells, following the selectin-mediated initial adhesion to endothelial cells. The expression of alpha2 beta1 and alpha3 beta1 integrins in esophageal cancer cells (TE-1 and T.Tn), strongly expressing EGF-receptors, were markedly increased by the addition of the heparin-binding EGF like growth factor (HB-EGF). The increase of integrin expression in esophageal cancer cells was inhibited by the addition of the tyrosine kinase inhibitor, genistein. HB-EGF treatment of esophageal cancer cells resulted in the augmentation of cancer cell adhesion to immobilized collagen. When esophageal cancer cells were co-cultured with endothelial cells, similar levels of augmentation of cancer cell adhesion to collagen were observed. The augmentation of cancer cell adhesion to collagen was inhibited by the addition of anti-HB-EGF neutralizing antibody. Our interpretation of the results described above is that the cancer cells receive stimulation from cytokines, such as HB-EGF, produced by endothelial cells, following initial adhesion of cancer cells via selectins. This results in a secondary increase in the expression of cell adhesion molecules, such as the beta1 integrin family, and leads to augmentation in the adhesive activities of cancer cells at vessel walls. We postulate that this sequence of events involves the enhanced transmigration of cancer cells to extravascular tissues, following the selectin-mediated adhesion to the endothelium.

Sensitive flow-injection method with peroxyoxalate chemiluminescence detection combined with preparative high-performance liquid chromatography for determination of choline-containing phospholipids in human serum

A sensitive and rapid flow-injection analysis (FIA) of total choline-containing phospholipids (PLs) and a selective FIA method for the class assay of choline-containing PLs combined with preparative HPLC were described. The FIA method is based on peroxyoxalate chemiluminescence (PO-CL) detection of hydrogen peroxide enzymatically formed from choline-containing PL. The linear standard curves were obtained up to 1 nmol/20-microliters injection (r > 0.999) with the detection limits of 1.3-1.6 pmol at a signal-to-noise ratio of 2. The total amounts of choline-containing PLs in human serum were ranged from 1.63 to 3.19 mg/ml. The HPLC separation of choline-containing PLs was achieved with an aminopropyl-modified silica gel column using a mixture of acetonitrile-methanol-10 mM ammonium phosphate buffer pH 5.8 as eluent. The eluate corresponding to each choline-containing PL was collected, evaporated, dissolved in 0.1% Triton X-100 aqueous solution, and then injected into FIA system. The FIA method combined with preparative HPLC was applied to the assay of human serum.

Expression of the multidrug-resistance-associated protein (MRP) gene in human colorectal, gastric and non-small-cell lung carcinomas

MRP has been identified as another multidrug-resistance (MDR) gene and may be involved in an alternative MDR mechanism in some solid tumors. We investigated the expression of MRP mRNA in multidrug-resistance KB sublines (KB-8-5, KB-C2, C-A40 and C-A120), human non-small-cell lung carcinomas (NSCLC), gastric and colorectal carcinomas, and compared it with that in drug-sensitive human KB cells. MRP gene expression was elevated in 8 of 9 (89%) squamous-cell carcinomas of the lung. Furthermore, MRP expression in 4 squamous-cell carcinomas (L13, 18, 19 and 20) was more than 3.6 times higher than in KB-3-1 cells, and the average MRP mRNA expression level of all squamous-cell carcinomas was significantly higher than that of adenocarcinoma of the lung and of colorectal and gastric carcinomas. These results suggested that the MRP is responsible, at least in part, for drug resistance in some squamous-cell carcinomas of the lung.