Vandetanib (ZD6474), an inhibitor of VEGFR and EGFR signalling, as a novel molecular-targeted therapy against cholangiocarcinoma.

Cholangiocarcinoma is an intractable cancer, with no effective therapy other than surgical resection. Elevated vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) expressions are associated with the progression of cholangiocarcinoma. We therefore examined whether inhibition of VEGFR and EGFR could be a potential therapeutic target for cholangiocarcinoma. Vandetanib (ZD6474, ZACTIMA), a VEGFR-2/EGFR inhibitor, was evaluated. Four human cholangiocarcinoma cell lines were molecularly characterised and investigated for their response to vandetanib. In vitro, two cell lines (OZ and HuCCT1), both of which harboured KRAS mutation, were refractory to vandetanib, one cell line (TGBC24TKB) was somewhat resistant, and another cell line (TKKK) was sensitive. The most sensitive cell line (TKKK) had EGFR amplification. Vandetanib significantly inhibited the growth of TKKK xenografts at doses > or = 12.5 mg kg(-1) day(-1) (P<0.05), but higher doses (50 mg kg(-1) day(-1), P<0.05) of vandetanib were required to inhibit the growth of OZ xenografts. Vandetanib (25 mg kg(-1) day(-1)) also significantly (P=0.006) prolonged the time to metastasis in an intravenous model of TKKK metastasis. Inhibiting both VEGFR and EGFR signalling appears a promising therapeutic approach for cholangiocarcinoma. The absence of KRAS mutation and the presence of EGFR amplification may be potential predictive molecular marker of sensitivity to EGFR-targeted therapy in cholangiocarcinoma.

Molecular cloning of a human Ca2+-dependent cell-cell adhesion molecule homologous to mouse placental cadherin: its low expression in human placental tissues.

P-cadherin is a subclass of Ca2+-dependent cell-cell adhesion molecules present in mouse placenta, where its localization suggests a function of connecting the embryo to the uterus (Nose, A., and M. Takeichi. 1986. J. Cell Biol. 103:2649-2658). We recently identified a human cadherin detected by an mAb capable of disrupting cell-cell adhesion of A-431 cells, and found that it was closely related immunochemically to mouse P-cadherin. Curiously, this cadherin was undetectable in human placenta by immunohistochemical examination (Shimoyama, Y., S. Hirohashi, S. Hirano, M. Noguchi, Y. Shimosato, M. Takeichi, and O. Abe. 1989. Cancer Res. 49:2128-2133). We here report the cloning and sequencing of cDNA clone encoding the human homologue of mouse P-cadherin. The deduced amino acid sequence of the human P-cadherin consists of 829 amino acid and shows striking homology with mouse P-cadherin. On Northern blot analysis, human P-cadherin was scarcely expressed in human placenta in contrast to mouse P-cadherin, which was abundantly expressed in mouse placenta throughout pregnancy, and it was shown that E-cadherin, but not P-cadherin, was the major cadherin molecule in human placenta. Moreover, NIH3T3 cells transfected with human P-cadherin cDNA expressed the functional cadherin molecule, which was identical to the cadherin we had previously identified using the mAb, showing that this molecule really does mediate cell-cell adhesion and that the cadherin we detected immunochemically is undoubtedly human P-cadherin. The results obtained in this study support the idea that P-cadherin plays little role, if any, in Ca2+-dependent cell-cell binding in human placental tissue at least after several weeks of pregnancy.

Actinin-4, a novel actin-bundling protein associated with cell motility and cancer invasion.

Regulation of the actin cytoskeleton may play a crucial role in cell motility and cancer invasion. We have produced a monoclonal antibody (NCC- Lu-632, IgM, k) reactive with an antigenic protein that is upregulated upon enhanced cell movement. The cDNA for the antigen molecule was found to encode a novel isoform of nonmuscle alpha-actinin. This isoform (designated actinin-4) was concentrated in the cytoplasm where cells were sharply extended and in cells migrating and located at the edge of cell clusters, but was absent from focal adhesion plaques or adherens junctions, where the classic isoform (actinin-1) was concentrated. Actinin-4 shifted steadily from the cytoplasm to the nucleus upon inhibition of phosphatidylinositol 3 kinase or actin depolymerization. The cytoplasmic localization of actinin-4 was closely associated with an infiltrative histological phenotype and correlated significantly with a poorer prognosis in 61 cases of breast cancer. These findings suggest that cytoplasmic actinin-4 regulates the actin cytoskeleton and increases cellular motility and that its inactivation by transfer to the nucleus abolishes the metastatic potential of human cancers.

Genomic loss and epigenetic silencing of very-low-density lipoprotein receptor involved in gastric carcinogenesis.

Homozygous loss in the genomic sequence, a mechanism for inactivating tumor-suppressor genes (TSGs) in cancer, has been used as a tag for the identification of novel TSGs, and array-based comparative genomic hybridization (array-CGH) has a great potential for high-throughput identification of this change. We identified a homozygous loss of the very-low-density lipoprotein receptor (VLDLR) gene (9p24.2) from genome-wide screening for copy-number alterations in 32 gastric cancer (GC) cell lines using array-CGH. Although previous reports demonstrated mRNA or protein expression of VLDLR in various cancers including GC, the association between genomic losses or epigenetic silencing of this gene and carcinogenesis has never been reported before. Homozygous deletion of VLDLR was also seen in primary GCs, albeit infrequently, and about half of GC cell lines showed lost or reduced VLDLR expression. The VLDLR expression was restored in gene-silenced GC cells after treatment with 5-aza 2'-deoxycytidine. According to methylation analyses, hypermethylation of the VLDLR promoter region, which all of GC lines without its expression showed, occurred in some primary GCs. Restoration of VLDLR type I expression in GC cells reduced colony formation. These results suggest that not only the expression of VLDLR but also genetic or epigenetic silencing of this gene may contribute to tumor formation and be involved in gastric carcinogenesis.

Diffusion anisotropy and diffusivity of white matter tracts within the temporal stem in Alzheimer disease: evaluation of the "tract of interest" by diffusion tensor tractography.

PURPOSE: Our aim was to determine whether diffusion anisotropy and diffusivity of white matter tracts of the temporal stem in patients with Alzheimer (AD) can be evaluated independently by using diffusion tensor tractography. MATERIALS AND METHODS: Subjects included 15 patients with AD (11 women and 4 men; mean age, 74 years) and 15 age-matched control subjects (11 women and 4 men; mean age, 72 years). Diffusion tensor images were acquired by using echo-planar imaging. We drew tractographies of the uncinate fasciculus, inferior occipitofrontal fasciculus, and Meyer's loop, with diffusion tensor analysis software. We measured diffusion anisotropy, diffusivity, and the number of voxels along the "tracts of interest" and used the Student t test to compare results between patients with AD and controls. RESULTS: Values of diffusion anisotropy of the bilateral uncinate fasciculus and left inferior occipitofrontal fasciculus were significantly lower for patients with AD than for controls. Also, values of diffusivity in the bilateral uncinate fasciculus were significantly greater for patients with AD than for controls. There was no significant difference in diffusion anisotropy or diffusivity along Meyer's loop between the 2 groups. There was no significant difference in the number of voxels included in all constructed tracts between patients with AD and controls. CONCLUSION: White matter tracts of the temporal stem can be evaluated independently by using diffusion tensor tractography, which appears to be a promising technique for determining changes in white matter in degenerative diseases.

Distribution of blood group antigens A, B, H, and I(Ma) in mucus-producing adenocarcinoma of human lung.

The distribution of blood group antigens A, B, and H and their precursor antigen I(Ma) in the mucus of lung cancer patients was studied histochemically. Antigens A, B, and H compatible with the ABO status of the patients were expressed in the mucus of bronchial gland mucous cells and bronchial goblet cells except in a few patients presumed to be nonsecretors , while antigen I(Ma) was not expressed at all in these cells. In contrast, compatible antigens A, B, and H were decreased or not present in cancer cells but antigen I(Ma) accumulated. Accumulation of antigen I(Ma), which resulted from incomplete synthesis of antigens A, B, and H, was a tumor-associated phenomenon in the mucus of the lung and was found in all patients examined. However, the degree of this accumulation varied from patient to patient, and tumor cells showed marked heterogeneity even in an individual case. In addition, accumulation of antigen associated with loss of antigens A and B was demonstrated in cancer cell mucus of patients with a blood group status other than O. Expression of incompatible blood group antigen reactive with anti-A serum (A-like antigen) also was detected in cancer cell mucus of blood group B patients.

Distribution of hepatitis B surface and core antigens in human liver cell carcinoma and surrounding nontumorous liver.

The distribution of hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) in surgically removed liver cell carcinomas of 60 Japanese patients was studied by an immunohistochemical method. HBsAg was localized in the cytoplasm, and HBcAg was mainly in the nuclei of normal-appearing liver cells, dysplastic liver cells, and tumor cells. In some instances both HBsAg and HBcAg were contained in the tumor cells and liver cells. HBsAg was found in the nontumorous liver tissue of 30 patients (50%); nine of the HBsAg-containing nontumorous livers also contained HBcAg. HBsAg and/or HBcAg was detected in tumor cells in 7 (23%) of 30 cases with HBsAg-positive liver diseases.

Establishment and characterization of the human cholangiocarcinoma cell line HChol-Y1 in a serum-free, chemically defined medium.

A human cholangiocarcinoma cell line, designated as HChol-Y1, was established in a protein-free, chemically defined medium after a very short period of primary culture in 0.1% fetal bovine serum (FBS)-containing medium. The cell line has been propagated in this medium for 2 years. The cells grew as a monolayer and the doubling time was about 52 hours. Addition of FBS did not stimulate cell growth (population-doubling time = 50 hr) or increase saturation density. The cells grown in a protein-free medium secreted small amounts of carcinoembryonic antigen (CEA) and large amounts of carbohydrate antigen (CA) 19/9 (CEA: 12.5 +/- 2.1 ng/10(6) cells/48 hr; CA 19/9: 760 +/- 52 IU/10(6) cells/48 hr); these tumor markers were immunohistochemically demonstrated in HChol-Y1 cells. Addition of FBS slightly stimulated the production of CEA and CA 19/9. The HChol-Y1 cell line was xenotransplantable in athymic nude mice and increased the serum CEA and CA 19/9 levels in the tumor-bearing nude mice. For determination as to whether a human carcinoma cell line can proliferate and secrete CEA and CA 19/9 in synthetic medium without any protein supplements, the cells were cultivated long term (2 yr) in a protein-free, chemically defined medium. When this method of cultivation is used, it is easy to purify these substances from spent medium, because contaminating antigens such as FBS or other substances usually added to cultures are absent.

Histologic demonstration of antigens reactive with anti-p21 ras monoclonal antibody (RAP-5) in human stomach cancers.

The immunohistochemical reactivity of RAP-5, a monoclonal antibody (MoAb) raised against a synthetic peptide corresponding to positions 10-17 of the ras gene product from T24 bladder carcinoma, was studied in 96 surgically resected stomach cancers of humans. The cytoplasm of cancer cells in 65 cases (68%) was positively stained with MoAb RAP-5, although the staining was heterogeneous among cancer cells. There was no definite correlation between depth of tumor invasion and reactivity to MoAb RAP-5. Cancer cells of poorly differentiated tumors showed a tendency to react less frequently and less intensely to MoAb RAP-5. In nontumorous gastric mucosa, parietal cells and some portions of intestinal metaplasia were stained with MoAb RAP-5. These findings suggest an increased expression of the ras gene product (p21) in about two-thirds of gastric adenocarcinomas and in some nonneoplastic gastric epithelial cells.

Transplantation of human tumors in nude mice.

Ninety-one human tumors, including various common carcinomas, low-grade malignant tumors, and benign tumors, were transplanted into athymic nude mice. Tumor take was confirmed histologically for 22 neoplasms at the initial transplantation, and 14 serially transplantable tumors were established, including some hitherto unestablished or unreported, such as lung and hepatic cell carcinomas. Among the 91 tumors were 21, 14, and 13 carcinomas of the lung, stomach, and breast, respectively. Transplantability was highest in lung carcinomas (10/21), followed by gastric carcinomas (2/14) and breast carcinomas (1/13). Morphology of original tumors was retained well in most transplanted tumors, but desmoplastic or scirrhous tumors, such as gastric and breast carcinomas, tended to become medullary with a decrease in amount of tumor stroma. The ability to produce mucin in gastric carcinomas or melanin in malignant melanoma was maintained in serially transplantable tumors. In addition, ectopic production of adrenocorticotropin and beta melanocyte-stimulating hormone continued in a transplanted small cell carcinoma of the lung. Preliminary results were obtained on hormone dependency of the transplantable breast carcinoma and on alpha1-fetoprotein in the transplantable hepatic cell carcinoma.

Expression of carbohydrate antigen 19-9 and stage-specific embryonic antigen 1 in nontumorous and tumorous epithelia of the human colon and rectum.

The expression of carbohydrate antigen 19-9 (CA 19-9) and stage-specific embryonic antigen 1 (SSEA-1) in various human colorectal epithelia was examined by an immunohistochemical method. In mucosa remote from the carcinoma, CA 19-9 was not expressed, whereas SSEA-1 was only faintly expressed in lower crypts in all cases. In mucosa adjacent to the carcinoma, CA 19-9 was weakly expressed in upper crypts in 20% of the cases, whereas SSEA-1 was expressed not only in lower crypts in all cases but also in upper crypts in 93.3% of the cases. In adenoma, CA 19-9 was expressed in 80.6% of the cases, and SSEA-1 was expressed in all cases. The expression of both antigens was to some extent related to the degree of cellular atypia. In focal carcinoma in adenoma, CA 19-9 was strongly and diffusely expressed in 50% of the cases, and SSEA-1 was strongly and diffusely expressed in all cases. In advanced carcinoma, CA 19-9 was homogeneously or heterogeneously expressed in 82.2% of the cases, and SSEA-1 was homogeneously or heterogeneously expressed in all cases, but lower intensity of SSEA-1 staining was associated with a decrease in the degree of carcinoma differentiation. These results show that the expression of both CA 19-9 and SSEA-1 changes along with neoplastic transformation and progression in the colon and rectum. Immunohistochemical studies of SSEA-1 in flat colorectal mucosa might be a useful approach for detecting foci with preneoplastic change in the general population, whereas those of SSEA-1 and CA 19-9 could be a useful method for detecting focal carcinoma in adenoma.

Expression of E- and P-cadherin in gastric carcinomas.

The expression pattern of two Ca2(+)-dependent intercellular adhesion molecules, E- and P-cadherin, in 54 surgically resected gastric adenocarcinomas was examined immunohistochemically. E-cadherin was expressed uniformly at the cell-cell borders of most of the differentiated and adherent-type undifferentiated gastric adenocarcinomas, showing that E-cadherin serves as the main cadherin molecule responsible for intercellular binding in these carcinomas. Scattered-type undifferentiated gastric adenocarcinomas which apparently lacked this tight intercellular adhesion were divisible into two groups on the basis of E-cadherin expression. In a minor group composed of 4 carcinomas, E-cadherin could not be detected, suggesting that the absence of E-cadherin made the cancer cells separate. In contrast, cancer cells of 19 carcinomas which belonged to the major group showed similar scattering but had definite expression of E-cadherin on their cell surfaces, suggesting that there was some mechanism(s) disturbing the function of E-cadherin in these carcinomas. However, immunoblotting showed no evidence of gross alterations of the E-cadherin molecule, such as partial deletion, in these carcinomas. P-cadherin was expressed in 29 (54%) of the examined gastric carcinomas, and the expression was unstable in most of them, a characteristic feature compared with the stable expression of E-cadherin. Since P-cadherin is known to be expressed temporarily in the foregut during embryogenesis and was proved to be occasionally expressed, although weakly, in the proliferative zone of noncancerous gastric epithelia in this study, expression of P-cadherin in gastric carcinomas may be an oncofetal phenomenon and/or may reflect their marked proliferative potential.

Identification of multiple breast cancers of multicentric origin by histological observations and distribution of allele loss on chromosome 16q.

Breast cancer is often detected as multiple lesions clinically and/or histopathologically. To examine if the origin of such lesions can be identified objectively by comparison of their loss of heterozygosity (LOH) patterns, LOH on chromosome 16q was analyzed in a total of 60 cases of multiple breast cancer by Southern blot analysis. Based on continuity among tumors and satellite nodule features, 30 cases of unilateral multiple cancer were classified morphologically into 3 groups: A, multicentric origin (11 cases); B, multifocal invasion of one intraductal carcinoma (15 cases); and C, intramammary metastases (4 cases). As controls, group D, synchronously bilateral breast cancers (11 cases), and group E, sets of a primary tumor and a lymph node metastasis (19 cases), were also examined. On a highly probable assumption that LOH on 16q occurs randomly in 50% of breast cancer cases at an early stage, the number of cases showing a concordant LOH pattern on 16q among tumors was compared between observed data, and the value was estimated from a normal distribution model in each group. In groups A and D, the allele pattern on 16q among tumors was concordant in 5 of 11 cases each, thus supporting their independent occurrence and multicentric origin, whereas the LOH pattern among tumors was identical in all of the cases in groups B, C, and E, thus supporting their monocentric origin. This comparison of the LOH pattern in multiple breast cancer was shown to yield results compatible with the morphological classification and was suggested to be of diagnostic value.

Different pattern of chromosomal allele loss in multiple hepatocellular carcinomas as evidence of their multifocal origin.

One of the most problematic aspects of surgery for hepatocellular carcinoma (HCC) is the frequent development of multiple tumors. Determination of the origin of multiple tumors, i.e., multifocal or metastatic, is important for predicting the clinical course of the disease after surgery. In order to clarify the origin of multiple tumors of HCC genetically, we examined patterns of loss of heterozygosity (LOH) on chromosome 16 for DNA isolated from 43 HCCs resected from 19 patients by analysis of restriction fragment length polymorphism. The cases were classified macro- and microscopically into 3 groups: multifocal origin; metastatic origin; and undetermined. Classification based on morphological features was shown to be well correlated with patterns of LOH in multiple tumors of HCC. Different patterns of LOH on chromosome 16 were detected in 8 of 11 patients with tumors of morphologically multifocal origin, whereas they were detected in none of 5 patients with tumors of morphologically metastatic origin. Among five patients with tumors of morphologically undetermined origin, a difference of LOH pattern among the tumors was detected in two, whereas in the other three, the pattern was identical between the tumors. A different pattern of LOH among HCCs arising in situ showed that they were composed of different clones, strongly suggesting their independent clonal origin and multifocal development. These results show that not only appropriate morphological observation but also examination of the LOH pattern on a particular chromosome is useful in diagnosis of multifocal HCC.

DNA hypermethylation at the D17S5 locus in non-small cell lung cancers: its association with smoking history.

The aim of this study was to examine the association between DNA hypermethylation and clinicopathological features of non-small cell lung cancers (NSCLCs). The DNA methylation status at the D17S5 loci, at which a candidate tumor suppressor gene, HIC-1 (hypermethylated in cancer), was identified, of 51 paired tumor and nontumorous lung tissue specimens from NSCLC patients was examined by Southern blot analysis, using a methylation-sensitive restriction enzyme. DNA hypermethylation at this locus was found in 17 (33%) tumors and 16 (31%) nontumorous lung tissues. DNA in hypermethylation at this locus occurred more frequently in poorly than in well-differentiated tumors, especially in adenocarcinomas, and correlated significantly with the differentiation grade (P = 0.01). DNA hypermethylation at the D17S5 locus correlated significantly with the loss of heterozygosity at this locus in tumors (P = 0.01). The incidence of DNA hypermethylation was significantly higher in smokers than those who had never smoked in both tumors and nontumorous lung tissues (P = 0.03 and P = 0.01, respectively). These results suggest that DNA hypermethylation at the D17S5 locus may play a role in the development of NSCLCs in cigarette smokers.

Aberrations of the tumor suppressor p53 and retinoblastoma genes in human hepatocellular carcinomas.

Aberrations of the p53 gene in 43 primary hepatocellular carcinomas (HCCs) were examined by single-strand conformation polymorphism analysis of polymerase chain reaction products. Of these hepatocellular carcinomas, 22 were advanced HCCs, and 21 were early HCCs. Structural abnormalities of the p53 gene were observed in eight of the 22 advanced HCCs, but in none of the early HCCs. Of the eight tumors with an abnormal p53 gene, seven had lost one of the two p53 alleles and, in the seven tumors with identifiable mutations, point mutations were found in four tumors and deletions of several nucleotides were observed in two tumors. The remaining one retained both alleles and carried two point mutations. In addition to the aberrations of the p53 gene, loss of the retinoblastoma gene or loss of heterozygosity at chromosome 13q was observed in six of seven informative cases of eight tumors carrying a mutated p53 gene. These results suggest the involvement of at least two tumor suppressor genes in a late stage of hepatocarcinogenesis.

Allele loss on chromosome 16q24.2-qter occurs frequently in breast cancers irrespectively of differences in phenotype and extent of spread.

Loss of heterozygosity on chromosomal arm 16q has been shown to be a frequent event in sporadic breast cancer and is suggested to be involved in cancer development through inactivation of a tumor-suppressor gene. To specify the commonly deleted region in which the unknown tumor-suppressor gene is located, a deletion map of chromosome 16 was constructed for 78 breast cancers, using 27 polymorphic DNA markers. Loss of heterozygosity on chromosome 16q was detected in 38 of the tumors. From the deletion map, the incidence of the loss of heterozygosity was deduced to be > or = 36% in the region distal to 16q12 and was most frequent in the 16q24.2-qter region. Then, association of the loss of heterozygosity in the 16q24.2-qter region with clinicopathological parameters of the tumors was examined for a total of 234 tumors, to reveal its biological significance in breast cancer development. The total incidence of loss of heterozygosity in the 16q24.2-qter region was 52% (118 of 225), and loss of heterozygosity was frequent irrespectively of the presence of invasion and metastasis, differences in clinical stage, tumor size, histological grade, or type, or amounts of estrogen receptor. Inactivation of an unknown tumor-suppressor gene on 16q24.2-qter was thus suggested to be involved commonly in the genesis of sporadic breast cancer, irrespectively of the extent of tumor spread or grade of aggressiveness of the cancer cells. On the other hand, eight cases revealed loss of heterozygosity not at 16q24-qter but in more proximal regions. Therefore, it appears that multiple tumor-suppressor genes are located on chromosome 16q.

Detection of frequent p53 gene mutations in primary gastric cancer by cell sorting and polymerase chain reaction single-strand conformation polymorphism analysis.

Mutations of the p53 gene were investigated after tumor cell enrichment by cell sorting based on differences in DNA content and polymerase chain reaction single-strand conformation polymorphism analysis in 24 surgical specimens of primary gastric cancer. p53 mutations were detected in exons 4-8 in 64% (9 of 14) of aneuploid tumors but in none of 10 diploid tumors examined. Four of five tumors containing two or three aneuploid subpopulations showed the presence of p53 gene mutations. No correlation was found between the presence of p53 mutations and the degree of histological differentiation of tumors. These findings suggest that p53 gene mutations are related to DNA ploidy alterations as relatively late events of carcinogenesis in gastric cancer. The present method is highly sensitive for detection of genetic abnormalities and is applicable even when various kinds of nontumorous cells are present in tumor samples.

Qualitative and quantitative changes of human tenascin expression in transformed lung fibroblast and lung tumor tissues: comparison with fibronectin.

Qualitative and quantitative alterations of human tenascin (TN) expression in virally transformed lung fibroblasts and in lung tumor tissues were investigated using S1 nuclease protection analysis in comparison with those of fibronectin (FN). Transformed fibroblasts and fetal lung tissues expressed more TN mRNA with an extra sequence encoding the sixth FN type III repeat than did normal cells and adult tissues. The splicing pattern of TN mRNA was also altered in many lung cancer tissues, showing increased or sometimes decreased expression of the TN mRNA with the extra sequence when compared with their surrounding normal tissues. These results provide additional evidence for the oncodevelopmental regulation of alternative RNA splicing in human lung tissues, first observed with FN mRNA (F. Oyama, et al., Cancer Res., 50: 1075-1078, 1990). Quantitative analysis of the levels of TN and FN mRNAs showed that the ratio of TN mRNA to FN mRNA was significantly increased in transformed fibroblasts and in some lung tumor tissues, when compared with their normal counterparts. Among different types of lung tumors, a significant increase of the TN/FN ratio was observed with most squamous cell carcinoma but with only a small fraction of adenocarcinoma. Since TN has been shown to inhibit cell adhesion to FN, the altered ratio of TN mRNA to FN mRNA may well affect the adhesive and migratory properties of tumor cells in lung cancer tissues.

Compensatory occurrence of IV2Fucalpha,II3NeuAcalpha-Gg4Cer and human fetal antigen Lc4Cer in small cell carcinomas of the human lung.

By means of a thin-layer chromatography immunostaining procedure involving a human monoclonal anti-Lc4Cer antibody, which was established by hybridizing murine myeloma cells and human lymphocytes from a cancer patient, Lc4Cer was proven to be a fetal antigen of human lung and to be a cancer-related antigen in small cell carcinomas of human lung, but not of other lung cancers, i.e., large cell carcinomas, adenocarcinomas, and squamous carcinomas. With the simultaneous detection of IV2Fuc alpha,II3NeuAc alpha-Gg4Cer with rabbit anti-IV2Fuc alpha,II3NeuAc alpha-Gg4Cer antiserum, the expression of Lc4Cer and IV2Fuc alpha,II3NeuAc alpha-Gg4Cer was found to be compensatory and, consequently, small cell lung carcinomas could be classified into Lc4Cer- and IV2Fuc alpha,II3NeuAc alpha-Gg4Cer-expressing types, L-SCLC and F-SCLC, respectively, which were detected in four and 27 of 31 patients' tissues and in one and three of four nude mouse-transplanted small cell lung carcinoma tissues, respectively. The compensatory expression of Lc4Cer and IV2Fuc alpha,II3NeuAc alpha-Gg4Cer in small cell carcinomas indicated that different metabolic pathways for glycosphingolipids were activated to give the distinct glycosphingolipid compositions in the two types of small cell lung carcinomas.