Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neural Cell Adhesion Molecules”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1994

Characterization of Pax-6 and Hoxa-1 binding to the promoter region of the neural cell adhesion molecule L1.

The neural cell adhesion molecule L1, a member of the immunoglobulin superfamily, mediates cell interactions in the developing and regenerating nervous system of mammals and is also detectable in the immune system and in the epithelia of intestine, skin, lung, and kidney. This diverse pattern of expression begs the question as to the regulatory mechanisms underlying transcription of the L1 gene. We demonstrate here that the paired domain and homeodomain containing Pax-6 protein binds to three different sites in the promoter region of the L1 gene. The promoter proximal binding site is also recognized by Hoxa-1 and lies approximately 60 bp upstream from the transcription start site only few base pairs upstream of a putative binding site for the TFII-I transcription initiation factor. On the basis of this sequence, we have characterized the binding of Pax-6 and explored two modes of its DNA binding activities.

Base Sequence↗
PubMed1989

Primary structure and developmental expression of a large cytoplasmic domain form of Xenopus laevis neural cell adhesion molecule (NCAM).

The neural cell adhesion molecule, (NCAM), is involved in cell-cell interactions during development of the vertebrate nervous system. NCAM exists in multiple protein forms and these are selectively expressed in different cells and at different times during development. Here we report the complete amino acid sequence of the large cytoplasmic form of Xenopus laevis NCAM, derived from a full-length cDNA clone. Using specific probes the expression of different NCAM transcripts during Xenopus embryogenesis has been examined. We find that transcripts encoding the large cytoplasmic domain form of NCAM exist in maternal RNA and that these are the only significant NCAM transcripts present until late gastrula when transcripts encoding the small cytoplasmic domain form of NCAM are first detected. No RNA encoding the small surface domain form of NCAM is detected during early development. These results indicate that the expression of NCAM sequences during early development of Xenopus differs from that described in other species.

Amino Acid Sequence↗
PubMed1988

Biochemical characterization of different molecular forms of the neural cell adhesion molecule L1.

The neural cell adhesion molecule L1 is a phosphorylated, integral membrane glycoprotein that is recovered from adult mouse brain tissue by immunoaffinity chromatography as a set of polypeptides with apparent molecular masses of 200, 180, 140, and 80 kilodaltons (L1-200, L1-180, L1-140, and L1-80, respectively). It has been shown that L1-140 and the phosphorylated L1-80 is generated from L1-200 by mild proteolytic treatment of intact cells. In the present study we have investigated the structural relationships between the different molecular forms of L1 and their location with regard to the surface membrane. We could show that L1-200 has two preferred cleavage sites, one that generates the amino terminal, extracellularly exposed L1-140 and the carboxy terminal L1-80 that spans the membrane. Cleavage at the other site leads to the generation of the amino terminally located L1-180 and the membrane-attached, phosphorylated carboxy terminal L1-30. This site is cleaved during treatment of live cultured cells with broad-spectrum, protease-free phospholipase C (but not phosphatidylinositol-specific phospholipase C) or exposure to sodium azide or cyanogen bromide. Other conditions that cause damage to cells do not lead to the generation of L1-180 and L1-30, suggesting a particular cell-intrinsic cleavage mechanism. L1-180 is truly soluble in aqueous solutions, since it can be recovered from culture supernatants and in the supernatant of a crude membrane fraction after incubation for 2 h at 37 degrees C. Although trypsin treatment alone does not release L1-140 into the supernatant, combination of phospholipase C and mild tryptic treatment leads to the release of L1-140 and L1-50, the latter being most likely the extracellularly exposed domain of L1-80 that is complementary to the membrane-integrated phosphorylated L1-30. Phase separation experiments with Triton X-114 show that the released forms of L1-180 and L1-140 distribute into the aqueous phase, whereas they distribute into the detergent phase when in association with L1-200 or L1-80. However, when L1-80 is cleaved to yield the soluble L1-50 and membrane-anchored L1-30, L1-140 is released into the supernatant together with L1-50. A strong affinity of L1-200, L1-140, and L1-80 to each other is also indicated by the fact that they incorporate together into liposomes and separate only under strong detergent conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

A protein kinase activity is associated with and specifically phosphorylates the neural cell adhesion molecule L1.

The neural cell adhesion molecule L1 is a phosphorylated integral membrane glycoprotein that is recovered from adult mouse brain by immunoaffinity chromatography as a set of polypeptides with apparent molecular masses of 200, 180, 140, 80, and 50 kilodaltons (L1-200, L1-180, L1-140, L1-80, and L1-50, respectively). In the present study, we show that two kinase activities are associated with immunopurified L1: One specifically phosphorylates L1-200 and L1-80 but not L1-180, L1-140, or L1-50. This pattern of phosphorylation corresponds to the one described for L1 after metabolic phosphate incorporation into cultures of cerebellar cells. In both cases, serine is the main amino acid that is labeled by radioactive phosphate. The kinase activity is not activated by Ca2+, calmodulin, phosphatidylserine, diolein, cyclic AMP, or cyclic GMP, a result suggesting that the enzyme is distinct from Ca2+/calmodulin-dependent kinases, from protein kinase C, or from cyclic AMP/cyclic GMP-dependent kinases and may belong to the independent kinase group. The other kinase phosphorylates only casein but not L1, utilizes GTP as well as ATP, and is strongly inhibited by heparin. Because the primary structure of the L1 protein does not contain consensus sequences characteristic for known kinases, we believe that the catalytic activities detectable in immunopurified L1 are due to kinases that are strongly enough associated with L1 to withstand the stringent purification procedures.

Animals↗
PubMed1990

Identification of positive and negative regulatory elements governing cell-type-specific expression of the neural cell adhesion molecule gene.

The neural cell adhesion molecule (NCAM) is one of the most prevalent cell adhesion molecules in vertebrates. Its expression is subject to complex cell-type- and developmental-stage-dependent regulation. To study this regulation at the level of transcription, we analyzed the promoter region of the mouse NCAM gene. The NCAM promoter did not contain a typical TATA box. Transcription started at several sites that were used indiscriminately by different cell types, implying that the different NCAM isoforms are expressed from a single promoter. Sequences responsible for both promotion and inhibition of transcription resided within 840 base pairs upstream of the main transcriptional start site. The sequence from positions -645 to -37 relative to the translation initiation site directed high levels of expression in NCAM-expressing N2A cells. The same fragment was six times less active but still significantly active in L cells, but this activity was repressed by inclusion of an additional upstream segment. We mapped eight domains of interactions with nuclear proteins within the 840-base-pair region. The segment with maximum promoter activity contained two adjacent footprints, the occupation of which appeared to be mutually exclusive. One of them corresponded to an Sp1-factor-binding consensus site, the other one bound a factor with nuclear factor I activity. The single protected domain in the fragment harboring a repressor activity consisted of a GGA repeat resembling negative regulatory elements in other promoters. Three adjacent binding sites occupied an A + T-rich segment and contained ATTA motifs also found in the recognition elements of homeodomain proteins. These results show that negative and positive elements interact to regulate the tissue-specific patterns of expression of the NCAM gene and indicate that a factor related to nuclear factor I is involved in its transcriptional control.

Animals↗
PubMed1994

New serum markers for small-cell lung cancer. II. The neural cell adhesion molecule, NCAM.

The neural cell adhesion molecule (NCAM) was recently suggested as a marker for small-cell lung cancer (SCLC). Immunohistochemical analysis demonstrated the presence of the NCAM in 78% of SCLC patients and in 25% of patients with other cancer forms. NCAM was proposed to be the most sensitive marker for SCLC, and it may also be an important prognostic marker for SCLC. We used a competitive ELISA to analyze the concentrations of NCAM in sera from 96 SCLC patients, 16 patients with non-SCLC, 4 patients with other cancer forms, and 16 healthy controls. All sera were collected at the time of diagnosis, before the patients received chemotherapy. The polyclonal antibody used in the assay recognized all three isoforms of NCAM. The concentration of NCAM was related to clinical parameters of the patients such as age, sex, blood group status, stage of disease, organ site involvement of metastases, survival, and expression of the ganglioside fucosyl-GM1 (FucGM1). Sera were considered positive if NCAM concentrations were higher than the mean concentration of healthy controls plus two standard deviations. Twenty-two percent of the sera from SCLC patients were positive for NCAM. No difference in concentration was found between SCLC patients with localized and extensive disease. Serum from one patient with cancer of the thyroid, but no sera from non-SCLC patients or normal healthy controls, was positive. The expression of NCAM did not correlate to any of the clinical parameters, and no correlation was found to the other serum marker, FucGM1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

Expression of highly polysialylated neural cell adhesion molecule in pancreatic cancer neural invasive lesion.

Neurotropism of pancreatic cancer is one of the hypotheses explaining neural invasion, which is one of the characteristics of pancreatic cancer. In these studies, we immunohistochemically examined neural cell adhesion molecules (NCAM), homophilic adhesion molecules expressed on the nerve cells, as a factor of neurotropism, in 15 pancreatic cancer operatively obtained, especially in neural invasive lesions. We also investigated the role of polysialic acid (PSA), which is attached to NCAM and related to the malignant potential of cancers. NCAM was detected in 66.7% of pancreatic cancers, and in all 9 cases with massive perineural invasion. In neural invasive lesions, however, there were perineurium and endoneurium, which do not express NCAM, between the cancer and nerve cells. PSA was also detected in the pancreatic cancers expressing NCAM. Moreover, PSA expression was stronger in the perineural invasive lesions than in the main tumor and was related to the cancer cell proliferation investigated by Ki-67 staining. It is unlikely therefore, that NCAM plays an important role in neurotropism. However, the NCAM expressed on the pancreatic cancer was attached to PSA, which itself plays an important role in the malignant potential of this disease.

Aged↗
PubMed2000

Alcohol exposure alters the expression pattern of neural cell adhesion molecules during brain development.

Neural cell adhesion molecules (NCAMs) play critical roles during development of the nervous system. The aim of this study is to investigate the possible effect of ethanol exposure on the pattern of expression and sialylation of NCAM isoforms during postnatal rat brain development because alterations in NCAM content and distribution have been associated with defects in cell migration, synapse formation, and memory consolidation, and deficits in these processes have been observed after in utero alcohol exposure. The expression of NCAM isoforms in the developing cerebral cortex of pups from control and alcohol-fed mothers was assessed by western blotting, ribonuclease protection assay, and immunocytochemistry. The highly sialylated form of NCAM [polysialic acid (PSA)-NCAM] is mainly expressed during the neonatal period and then is down-regulated in parallel with the appearance of NCAM 180 and NCAM 140. Ethanol exposure increases PSA-NCAM levels during the neonatal period, delays the loss of PSA-NCAM, decreases the amount of NCAM 180 and NCAM 140 isoforms, and reduces sialyltransferase activity during postnatal brain development. Neuraminidase treatment of ethanol-exposed neonatal brains leads to more intense band degradation products, suggesting a higher content of NCAM polypeptides carrying PSA in these samples. However, NCAM mRNA levels are not changed by ethanol. Immunocytochemical analysis demonstrates that ethanol triggers an increase in PSA-NCAM immunolabeling in the cytoplasm of astroglial cells, accompanied by a decrease in immunogold particles over the plasma membrane. These findings indicate that ethanol exposure during brain development alters the pattern of NCAM expression and suggest that modification of NCAM could affect neuronal-glial interactions that might contribute to the brain defects observed after in utero alcohol exposure.

Aging↗
PubMed2002

Dynamic change of neural cell adhesion molecule polysialylation on human neuroblastoma (IMR-32) and rat pheochromocytoma (PC-12) cells during growth and differentiation.

Polysialic acid (PSA) is a regulatory epitope of neural cell adhesion molecule (NCAM) in homophilic adhesion of neural cells mediated by NCAM, is also known to be re-expressed in several human tumors, thus serves as an oncodevelopmental antigen. In this study, using a recently developed ultrasensitive chemical method in addition to immunochemical methods, growth stage-dependent and retinoic acid (RA)-induced differentiation-dependent changes of PSA expression in human neuroblastoma (IMR-32) and rat pheochromocytoma (PC-12) cells were analyzed both qualitatively and quantitatively. Both IMR-32 and PC-12 cells expressed PSA on NCAM, and the level of PSA expressed per unit weight of cells increased with post-inoculation incubation time. The most prominent feature was seen at the full confluence stage. RA induced neuronal differentiation in both IMR-32 and CP-12 cells that paralleled the change in the PSA level. Chemical analysis revealed the presence of NCAM glycoforms differing in the degree of polymerization (DP) of oligo/polysialyl chains, whose DP was smaller than 40. DP distribution of PSA was different between the cell lines and was changed by the growth stage and the RA treatment. Thus DP analysis of PSA is important in understanding both mechanism and biological significance of its regulated expression.

Adrenal Gland Neoplasms↗
PubMed2005

Single molecule adhesion measurements reveal two homophilic neural cell adhesion molecule bonds with mechanically distinct properties.

Neural cell adhesion molecule (NCAM) is a cell surface adhesion glycoprotein that plays an important role in the development and stability of nervous tissue. The homophilic binding mechanism of NCAM is still a subject of debate on account of findings that appear to support different mechanisms. This paper describes single molecule force measurements with both full-length NCAM and NCAM mutants that lack different immunoglobulin (Ig) domains. By systematically applying an external, time-dependent force to the bond, we obtained parameters that describe the energy landscape of NCAM-NCAM bonds. Histograms of the rupture forces between the full-length NCAM extracellular domains revealed two binding events, one rupturing at higher forces than the other. These bond rupture data show that the two bonds have the same dissociation rates. Despite the energetic and kinetic similarities, the bond strengths differ significantly, and are mechanically distinct. Measurements with NCAM domain deletion mutants mapped the weaker bond to the Ig1-2 segment, and the stronger bond to the Ig3 domain. Finally, the quantitative agreement between the fragment adhesion and the strengths of both NCAM bonds shows that the domain deletions considered in this study do not alter the intrinsic strengths of either of the two bonds.

Amino Acid Sequence↗
PubMed1992

Cell adhesion molecules as targets for Hox genes: neural cell adhesion molecule promoter activity is modulated by cotransfection with Hox-2.5 and -2.4.

In an effort to determine whether homeobox genes modulate the activity of the promoter of the mouse neural cell adhesion molecule (N-CAM) gene, we have carried out a series of cotransfection experiments using NIH 3T3 cells. Plasmids were constructed containing Xenopus laevis Hox-2.5 and -2.4 coding sequences linked to a human cytomegalovirus promoter (CMV-Hox-2.5 and CMV-Hox-2.4). A 4.9-kilobase DNA fragment containing 5' flanking and first exon sequences of the mouse N-CAM gene was linked to a chloramphenicol acetyltransferase (CAT) reporter gene (N-CAM-Pro-CAT). Cotransfection with CMV-Hox-2.5 and N-CAM-Pro-CAT resulted in a strong induction of CAT activity. The N-CAM promoter contained two potential homeodomain binding sites (sites I and II) within a 47-base-pair segment (512-559 base pairs upstream of the ATG codon in the first exon of the N-CAM gene). This segment was linked to a minimal promoter (simian virus 40 early) and a downstream CAT gene. Although this construct was transcriptionally active at a low level in NIH 3T3 cells, cotransfection of CMV-Hox-2.5 resulted in CAT activity that was greatly elevated. Mutational studies revealed that it was the homeodomain binding site II sequence that was required for this regulation. In contrast, cotransfection with CMV-Hox-2.4 eliminated the CAT activity that was driven by the CMV-Hox-2.5 construct. Thus, the products of two related Hox genes, which are located adjacent to each other in the Hox-2 complex, can differentially modulate transcription from the promoter of a cell adhesion molecule gene. The results suggest that the N-CAM gene is likely to be a target for regulation by Hox gene products.

3T3 Cells↗
PubMed1993

Osteogenic protein-1 regulates L1 and neural cell adhesion molecule gene expression in neural cells.

Osteogenic protein-1 (OP-1) is a member of the TGF-beta superfamily that is expressed in the nervous system. We recently showed that human recombinant osteogenic protein-1 (hOP-1) strongly promotes the aggregation of dividing neuroblastoma x glioma hybrid NG108-15 cells, in part by inducing the major isoforms of the neural cell adhesion molecule (N-CAM) (Perides, G., Safran, R. M., Rueger, D. C., and Charness, M. E. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 10326-10330). Here we show that hOP-1 induces L1 expression approximately 6-fold in NG108-15 cells without changing the levels of N-cadherin, neurofilament 200, Thy-1, tau, and G alpha s. OP-1 induction of L1 and N-CAM was unassociated with changes in cell proliferation and was not reproduced by cellular differentiation. The increased adhesiveness of hOP-1-treated NG108-15 cells could be inhibited in part by Fab fragments of an anti-L1 polyclonal antiserum. L1 and N-CAM expression first increased 12-18 h after hOP-1 treatment, reached a maximum after 2-3 days, persisted for up to 5 days, and returned to control levels 3 days after hOP-1 withdrawal. The increases in L1 and N-CAM protein levels were preceded or accompanied by large increases in the abundance of L1 and all detectable N-CAM mRNAs. Actinomycin D prevented the induction by hOP-1 of L1 and N-CAM mRNAs, suggesting that hOP-1 regulates immunoglobulin CAM gene transcription. OP-1 is the first described growth factor that regulates both N-CAM and L1 gene expression.

Bone Morphogenetic Protein 7↗
PubMed2001

Regulation of cell adhesion by polysialic acid. Effects on cadherin, immunoglobulin cell adhesion molecule, and integrin function and independence from neural cell adhesion molecule binding or signaling activity.

The polysialylation of neural cell adhesion molecule (NCAM) evolved in vertebrates to carry out biological functions related to changes in cell position and morphology. Many of these effects involve the attenuation of cell interactions that are not mediated through NCAM's own adhesion properties. A proposed mechanism for this global effect on cell interaction is the steric inhibition of membrane-membrane apposition based solely on polysialic acid (PSA) biophysical properties. However, it remains possible that the intrinsic binding or signaling properties of the NCAM polypeptide are also involved. To help resolve this issue, this study uses a quantitative cell detachment assay together with cells engineered to display different adhesion receptors together with a variety of polysialylated NCAM polypeptide isoforms and functional domain deletion mutations. The results obtained indicate that regulation by PSA occurs with adhesion receptors as diverse as an IgCAM, a cadherin and an integrin, and does not require NCAM functional domains other than those minimally required for polysialylation. These findings are most consistent with the cell apposition mechanism for PSA action, as this model predicts that the inhibitory effects of PSA-NCAM on cell adhesion should be independent of the nature of the adhesion system and of any intrinsic binding or signaling properties of the NCAM polypeptide itself.

Animals↗
PubMed1998

Polysialic acid on the neural cell adhesion molecule correlates with expression of polysialyltransferases and promotes neuroblastoma cell growth.

Neuroblastomas and cell lines derived from these tumors bear the oncodevelopmental antigen polysialic acid (PSA) bound to the neural cell adhesion molecule. Polysialyation of neural cell adhesion molecule can be achieved by two different polysialyltransferases, ST8SiaII and ST8SiaIV. This study was undertaken to investigate the pattern of polysialyltransferases expressed in the human neuroblastoma cell line SH-SY5Y. Reverse transcription-PCR showed simultaneous expression of the two enzymes, and in situ hybridization demonstrated that the polysialyltransferase mRNA expression parallels immunoreactivity with the PSA-specific monoclonal antibody 735. After retinoic acid-induced differentiation, only the PSA-positive, neuron-like cell type gave clear signals for ST8SiaII and ST8SiaIV in in situ hybridization, whereas both signals were drastically reduced in the weakly PSA-positive substrate adherent phenotype. Like the SH-SY5Y cells, a primary, PSA-positive neuroblastoma specimen revealed expression of the two polysialyltransferases. To investigate the role of PSA for cell growth and differentiation, SH-SY5Y cells were treated with the PSA-specific endo-N-acetylneuraminidase E. Although loss of PSA was accompanied with a marked reduction of cell growth, it did not interfere with retinoic acid-induced differentiation. Together, our results suggest that PSA surface expression is regulated on the level of polysialyltransferase transcription. Moreover, the similarity to the primary neuroblastoma tissue makes SH-SY5Y cells a suitable model system to examine further the role of polysialylation in tumor cell growth and the orchestration of PSA synthesis in neuroblastoma.

Cell Differentiation↗
PubMed2001

Expression of neural cell adhesion molecule in pancreatic cancer.

Neural cell adhesion molecule (NCAM) has been found to be a significant factor for survival in various solid tumors. In the present study, we examined the expression of NCAM in exocrine tumors of the pancreas by immunohistochemistry, using two monoclonal antibodies against NCAM and polysialic acid (MAB735). Expression of NCAM was seen mainly in the cytoplasm of the following cells: regenerating duct cells among neoplastic tissue, hyperplastic islet cells, intrapancreatic nerves and ganglia, as well as tumor cells. There was no reactivity with MAB735. We found a significant correlation between intense NCAM expression (i.e., expression in more than 50% of all tumor cell mass) and survival rates in tubular adenocarcinoma, particularly moderately differentiated tumors (p < 0.05). There was no statistically significant relation between NCAM reactivity and tumor stage or any of the clinicopathologic parameters described by the Japan Pancreas Society (p > 0.05). We conclude that the expression of NCAM in tubular adenocarcinoma of the pancreas, particularly in moderately differentiated tumors, has a significant impact on the overall patient survival.

Adult↗
PubMed2001

Mutation in the neural cell adhesion molecule interferes with the differentiation of anterior pituitary secretory cells.

The neural cell adhesion molecule (NCAM) and its polysialylated isoform (PSA-NCAM) have been shown to influence the proliferation, differentiation and survival of different cell types. Here, we report the pattern of expression of NCAM and PSA-NCAM in the anterior lobe (AL) of the pituitary gland of the adult mouse. We demonstrate that the majority of cells express NCAM, while PSA-NCAM is retained mostly on corticotropes. Analysis of bromodeoxyuridine (BrdU) incorporation shows that the presence of PSA-NCAM on corticotropes is not related to proliferation but most likely to their functional properties. We subsequently analyzed defects induced by NCAM deficiency in adult NCAM knockout mice. In these mice, all secretory cell types in the AL are present and their distribution within the gland is similar to that in wild-type mice. However, proliferation of AL cells is significantly increased. In particular, more BrdU-positive cells are detected among somatotropes and mammotropes in NCAM-deficient mice. In addition, the percentages of secretory cells are changed: somatotropes are more numerous while the number of corticotropes is reduced. These data demonstrate the involvement of NCAM in the proper generation and/or maintenance of the different cell populations in the AL and suggest the importance of PSA in corticotrope functioning.

Animals↗
PubMed2000

NCAM (neural cell adhesion molecules) expression in malignant mesotheliomas.

Neural cell adhesion molecules (NCAM) are adhesion molecules expressed by neural and neuroendocrine tumors and a few biphasic tumors such as synovialosarcomas and breast phyllode tumors. To investigate NCAM expression in mesotheliomas, we studied 26 cases of epithelioid (n = 12), biphasic (n = 11), and sarcomatoid (n = 3) malignant mesotheliomas (MM), in comparison with normal mesothelium, and 50 primary non-small cell lung carcinomas (NSCLC) (25 adenocarcinomas [ADC] and 25 squamous cell carcinomas [SCC]), using electron microscopy as a gold standard for recognition of MM. NCAM reactivity using 123C3 antibody was compared with that of NE markers such as chromogranin A and synaptophysin. Although normal mesothelium remains negative, NCAM was expressed in 19 of 26 MM (73%) with a membranous staining on frozen or paraffin sections. In 6 of 12 epithelioid MM, the tumor cells expressed NCAM, whereas in 5 cases stromal fibroblasts showed a strong but focal staining. In 11 biphasic MM, 4 presented an NCAM reactivity of both epithelioid and spindle cell components, whereas in 7, only fusiform component was NCAM positive. Two of 3 sarcomatoid MM showed an NCAM expression. Chromogranin expression was never seen, whereas synaptophysin was noticed in 2 cases. No case of NSCLC showed membranous 123C3 staining, whereas 2 ADC weakly expressed synaptophysin. We conclude that NCAM expression in MM is reminiscent of its expression in mesoderm during fetal life and consistent with that reported in other biphasic tumors. These data show that NCAM expression occurs in 73% of MM, highly exceeding that observed in lung cancer.

Adenocarcinoma↗
PubMed1993

Expression of highly polysialylated neural cell adhesion molecule in calcitonin-producing cells.

Calcitonin-producing cells are endocrine derivatives of the neural crest and have several neuron-like properties. Expression of the neural cell adhesion molecule in calcitonin-producing cells was examined using two types of antibodies to neural cell adhesion molecule: monoclonal antibody 12E3 recognizes the polysialic acid portion of highly polysialylated neural cell adhesion molecule, and monoclonal antibody AF11 and polyclonal antiserum react with the polypeptide portion common to three major isoforms of neural cell adhesion molecule. An immunohistochemical study revealed that highly polysialylated neural cell adhesion molecule was expressed both in fetal rat thyroidal calcitonin-producing cells and in a calcitonin-producing cell line, rMTC 6-23, established from explantable neoplasm of rat calcitonin-producing cells. The neural cell adhesion molecule in the rMTC 6-23 cells was further characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis. Two anti-neural cell adhesion molecule monoclonal antibodies, 12E3 and AF11, revealed a broad positive band around 200,000-250,000 mol. wt in solubilized proteins. When the polysialic acids were eliminated by neuraminidase treatment, the immunoreactivity to monoclonal antibody 12E3 was completely abolished, and core polypeptide corresponding to neural cell adhesion molecule with a molecular weight of 120,000 was detected by monoclonal antibody AF11. These results suggest that cells of the calcitonin-producing cell line express on their surfaces highly polysialylated 120,000 mol. wt form of neural cell adhesion molecule polypeptide.

Animals↗