Biomedical subjects

S Sekiya

Publications and source records attributed to S Sekiya.

At least 19 recordsLinked to original sources

PubMed1992

Dipyridamole enhances an anti-proliferative effect of interferon in various types of human tumor cells.

The anti-proliferative activity of human interferon (HuIFN) was enhanced by dipyridamole, 2,6-bis-(diethanolamino)-4,8-dipiperidinopyrimido-[5,4-d]-py rimidine, when tested against various human tumor cell lines, including KT (breast carcinoma), PLC/PRF/5 (hepatoma), MGC-I, U251-SP and T98 (glioma), HAC-2 and SHIN-3 (ovarian carcinoma), and MM-ICB (melanoma). The enhancement occurred irrespective of the kind of HuIFN used (alpha, beta or gamma) and the original degree of susceptibility of the cells to HuIFN. Even low doses down to 0.01 microM of dipyridamole that had no intrinsic anti-proliferative activity could enhance the effect of HuIFN. The enhancement of HuIFN effects seems not to be caused by induction of HuIFN production, because neither anti-viral activity nor HuIFN antigens were detected in culture medium in cells treated with dipyridamole. Mopidamole, a derivative of dipyridamole lacking one piperidine residue, produced little enhancement of the effects of HuIFN. Among ovarian cancer cell lines tested, the enhancement of the activity of HuIFN by dipyridamole for HAC-2 and SHIN-3 cells was equivalent to or greater than that for 3 chemotherapy agents (adriamycin, vincristine, and a camptothecin derivative). However, neither HOC-21 ovarian cancer cells nor HEC-1 endometrial adenocarcinoma cells were susceptible to any combinations. When MGC-1, U251-SP, and HAC-2 cells were injected into nude mice, the growth of tumors was more markedly inhibited by the subcutaneous administration of HuIFN in combination with oral administration of dipyridamole than by the HuIFN alone. Thus, this combination therapy seems to be worth trying for human cancer, although the enhancement of the effects of HuIFN by dipyridamole varied among the cell lines examined.

Animals↗

PubMed1992

Expression of a human multidrug resistance gene in human ovarian carcinoma cell lines.

To investigate the possible role of the multidrug resistance phenotype to chemoresistance in human ovarian carcinoma, we have analyzed human multidrug resistance gene (mdr 1) expression in 8 human ovarian adenocarcinoma cell lines. An increase in P-glycoprotein level specific to multidrug-resistant tumor cells was not apparently associated with the increase in resistance to vincristine (VCR) or doxorubicin (Adriamycin). Mdr 1 transcripts (4.5 kilobases) were observed in the RNA preparation obtained from only one cell line (SHIN-3) that showed the highest resistance to both drugs in vitro and in vivo. No cell lines showed mdr 1 DNA amplification. These results suggest that the insensitivity of human ovarian carcinoma to chemotherapy could be partly explained by the expression of mdr 1.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1992

[An aberrant muscular nerve to the latissimus dorsi muscle from the posterior cutaneous nerve of the arm].

In the 1987 student course on gross anatomy dissection of cadavers at Iwate Medical University School of Medicine, an aberrant muscular nerve to the latissimus dorsi muscle arising from the posterior cutaneous nerve of the arm was found bilaterally in a 65-year-old female who had died of acute pneumonia. The case was investigated anatomically. The posterior cutaneous nerve of the arm arose from the radial nerve approximately at the lateral axial border as the first branch independently on the right, and by forming a trunk with the nerve to the long head of the triceps brachii muscle on the left. The aberrant muscular nerve originated from the posterior cutaneous nerve of the arm about 3 cm distally to the point of the branching of the cutaneous nerve from the radial nerve. This aberrant nerve entered the latissimus dorsi muscle near the transitional area from the muscular part to the tendinous part while dividing into three on the right, and without dividing on the left. The side into which the aberrant nerve entered was just the reverse of the side into which the thoracodorsal nerve and artery supplied. The muscular part innervated by the aberrant nerve was bounded by a tendinous intersection for the most part of the latissimus dorsi muscle innervated by the thoracodorsal nerve. The intramuscular nerve distribution of the aberrant nerve was investigated under a binocular dissecting microscope. It was revealed that there was no communication between the ramification of the aberrant nerve and that of the thoracodorsal nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

[Bilateral absence of the quadrangular space of the axilla].

In the 1988 student course on gross anatomy dissection of cadavers at Iwate Medical University School of Medicine, two cases of the absence of the quadrangular space of the axilla were found bilaterally in a 92-year-old female who had died of heart failure. The cases were investigated anatomically. The tendons of insertion of the latissimus dorsi and the teres major muscles and the tendon of origin of the long head of the triceps brachii muscle were united, forming a conjoint tendon that attached to the infraglenoid tubercle of the scapula and the lower part of the anatomical neck of the humerus adhering to the articular capsule of the shoulder joint. The subscapularis muscle was normal except that a muscular bundle arose from the conjoint tendon and inserted to the lesser tubercle of the humerus and the crest continuing down from the tubercle. A part of the conjoint tendon was covered by the insertion of the subscapularis muscle, and there was no space between the conjoint tendon and the insertion of the subscapularis muscle. The teres major muscle was poorly developed, but the area of origin was rather wide and arose from both the dorsal and costal surfaces of the scapula. The anatomical features of the latissimus dorsi and the long head of the triceps brachii muscles were normal except for the insertion of the former and the origin of the latter. The triangular space of the axilla was found to be surrounded by the conjoint tendon, teres major muscle, and the lateral border of the scapula covered by the subscapularis and the teres minor muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

Interaction of nuclear factors with the regulatory region of the N-myc gene during differentiation of human embryonal carcinoma cells.

The human embryonal carcinoma cell line, NEC14, can be induced to differentiate by the addition of 10(-2) M N,N'-hexamethylene-bis-acetamide (HMBA). During the early stage of HMBA-induced differentiation, the level of N-myc expression decreased steeply and transiently, and then quickly returned to its original level after reaching a minimal level at 18 h after addition of HMBA. Nuclear run-on experiments indicated that this transient decrease is regulated at the transcription start point. To investigate the mechanism of this down-regulation, the 5'-flanking region of the human N-myc gene was cloned and sequenced. Computer analysis of the sequence revealed high homology with the 5'-flanking region of the mouse N-myc gene, especially (greater than 80%) in the region of nt positions -1777 to -1732, nt positions -763 to -501 and nt positions -260 to + 1. The patterns of protein binding to the upstream region during the early stage of NEC14 cell differentiation were analyzed by gel retardation assay. The DNA fragments VIII and X, containing the sequences of nt positions -1437 to -1237 and nt positions -1863 to -1710, respectively, formed the DNA-protein complexes which were greatly reduced in quantity in the cell extract prepared 18 h after the addition of HMBA. This reduction, however, was not observed with an extract similarly prepared from the NEC14 derivative cell line, H10, expressing the N-myc gene constitutively. These results suggest a causal connection between the complex formation and the high-level transcription of the N-myc gene.

Acetamides↗

PubMed1991

Neural rosette formation within in vitro spheroids of a clonal human teratocarcinoma cell line, PA-1/NR: role of extracellular matrix components in the morphogenesis.

From the human teratocarcinoma-derived cell line PA-1, we established a clonal line, PA-1/NR, that stably produced a distinct cellular arrangement of neural rosettes when cultured as in vitro multicellular spheroids for 3 weeks. On immunofluorescence staining and fluorescence-activated cell sorter analyses, PA-1/NR cells in monolayer expressed the neuroectoderm-associated antigens HNK-1, NC-1, and A2B5 and the neuroblastoma-associated antigens KP-NAC8 and KP-NAC10 but lacked human embryonal carcinoma antigens, SSEA-3 or K21 antigen. Here, we investigated the developmental process of rosette formation with respect to morphological features, distribution of mitotic cells, and expression of multiple lineage-related markers and extracellular matrix (ECM) components. Ultrastructural examination of these rosettes disclosed a well-defined cavity radially surrounded by wedge-shaped or pseudostratified cells, apical microvilli and junctional complexes, and basal laminae and collagen fibrils at their basal surface. In these rosettes, many proliferating cells were detected by the immunohistochemical staining of cells incorporating bromodeoxyuridine. PA-1/NR spheroids consistently displayed neuron-specific enolase, S-100 protein, and vimentin but not glial fibrillary acidic protein, neurofilament proteins, or myelin basic protein. The rosette formation accompanied a strikingly polarized and overlapped deposition of ECM components including tenascin-carrying HNK-1 epitopes, laminin, type IV collagen, heparan, and chondroitin sulfate proteoglycans. Immunoblotting analyses showed that laminin B1 and B2 chains were constitutively expressed, whereas a fully assembled form of laminin and type IV collagen appeared only after spheroid development, suggesting that these ECM components play a morphogenetically important role in rosette formation. Close similarities between these rosettes and the neural tube of humans and experimental animals in the morphogenetic process and ECM formation lead us to propose that the PA-1/NR spheroids provide an in vitro model for the study of the earliest stage of human neurogenesis.

Antibodies↗

PubMed1991

A newly developed in vitro chemosensitivity test (nuclear damage assay): application to ovarian cancer.

With a newly developed in vitro chemosensitivity test based on the morphological changes of nuclear damage (nuclear damage assay) described here, we were able to screen currently available anticancer drugs within 24 hr with a 100% success rate. In preclinical chemotherapy using four human ovarian epithelial tumor cell lines and their xenografts in nude mice, the in vitro/in vivo response (sensitive/sensitive and resistant/resistant) rate was 94%. The nuclear damage assay was used to determine the chemosensitivity in 49 patients (60 assays) with ovarian cancer. The response rate of the 13 patients with measurable tumors, 9 of whom showed resistance to CAP (cyclophosphamide, adriamycin, and cisplatin) therapy, was 46% when the patients were given various combination chemotherapy protocols consisting of more than one active agent selected from group A and B agents by the nuclear damage assay. The newly developed in vitro chemosensitivity test proved to be useful when selecting a second-line combination chemotherapy for patients with CAP-resistant ovarian cancer.

Animals↗

PubMed1991

Subtractive cDNA cloning using oligo(dT)30-latex and PCR: isolation of cDNA clones specific to undifferentiated human embryonal carcinoma cells.

The human embryonal carcinoma cell line NEC14 can be induced to differentiate by the addition of 10(-2)M N,N'-hexamethylene-bis-acetamide (HMBA). A subtractive cDNA library specific to undifferentiated NEC14 cells was constructed using oligo(dT)30-Latex and polymerase chain reaction (PCR). The method was designed to improve the efficiency of subtraction and the enrichment of cDNA clones corresponding to low abundance mRNAs. The single strand of cDNA was made from mRNA prepared from the HMBA-treated NEC14 cells using an oligo(dT)30 primer covalently linked to Latex particles. After removal of the mRNA template by heat-denaturation and centrifugation, the subtractive hybridization was carried out between the cDNA-oligo(dT)30-Latex and mRNA from untreated NEC14 cells. Unhybridized mRNA collected by centrifugation was hybridized repeatedly to the cDNA-oligo(dT)30-Latex and subtractive mRNA was converted to cDNA. The subtractive cDNA was then amplified by PCR and cloned into pBluescript II KS-. The cDNA library thus constructed consisted of approximately 10,000 independent clones with cDNA inserts of 1.7 Kb on average. Differential hybridization of these transformants indicated that approximately 3% of them contained cDNA inserts specific to the undifferentiated EC cells, some of which were derived from low abundance mRNAs.

Acetamides↗

PubMed1991

Characterization of a 54 kDa, alpha 1-antitrypsin-like protein isolated from ascitic fluid of an endometrial cancer patient.

A protein factor which stimulated [3H]thymidine uptake into free hepatocytes prepared from normal mouse liver was detected in the ascitic fluid of gynecological cancer patients. The factor was subsequently further purified from the ascitic fluid of an endometrial cancer patient by DEAE-Sephacel, Sephadex G-150 and Phenyl-Sepharose CL-4B column chromatographies, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a single protein band of 54,000 Da, designated tentatively as 54K ascitic protein (54K-AP). 54K-AP was similar to human alpha 1-antitrypsin (alpha 1-AT) in terms of SDS-PAGE and immunological behavior, but was slightly different in terms of amino acid sequence and isoelectric point. Although 54K-AP inhibited the activities of bovine trypsin and alpha-chymotrypsin as did human alpha 1-AT, 54K-AP inhibited the plasminogen activator released from human endometrial cancer Ishikawa cells more efficiently than alpha 1-AT. Because, in contrast to normal serum, the serum from the endometrial cancer patients stimulated [3H]thymidine uptake into hepatocytes, the possibility arises that 54K-AP could be produced by the cancer host as a defence mechanism against the cancer.

Amino Acid Sequence↗

PubMed1991

A transient decrease in N-myc expression and its biological role during differentiation of human embryonal carcinoma cells.

The human embryonal carcinoma (EC) cell line, NEC14 can be induced to morphologically differentiate by the addition of 10(-2) M N,N'-hexamethylene-bis-acetamide (HMBA) in vitro. The expression of several cellular oncogenes (c-onc) in NEC14 cells was examined after induction of differentiation by HMBA. The level of N-myc expression was the highest in undifferentiated cells but decreased transiently to less than 1/10 of the original level shortly after the induction of differentiation. To investigate the role of the transient decrease in N-myc level on NEC14 cell differentiation, a chimeric human N-myc gene in which transcription is initiated at the human beta-actin gene promoter was constructed and introduced into NEC14 cells. Several transformants expressing the exogenous N-myc gene constitutively were established. These transformants showed 10- to 70-fold increases in plating efficiency and shorter population doubling times as compared with the parental NEC14 cells. The transformants were hard to induce, spontaneously differentiated cells on the periphery of cell clusters in culture, unlike parental NEC14 cells, and took longer for HMBA-induced morphological differentiation. The populations of the cells expressing HLA and SSEA-1 antigens increased from 10%-20% to nearly 100% in NEC14 cells after the induction of differentiation, while the populations expressing these antigens increased only to 50%-60% in one of the transformants, S11. The transformants gained an increased tumorigenic potential in nude mice, and the tumors produced consisted exclusively of EC stem cells. These results suggest that the additional expression of the exogenous N-myc gene (increased about two-fold) confers the more transformed state on the cells.

Antigens, Surface↗

PubMed1991

Muscle architecture and intramuscular distribution of nerves in the human soleus muscle.

On the deep anterior surface of the human soleus muscle a bipenniform part is found, the portio anterior, which is innervated by the ramus anterior. This part and the innervation pattern are morphological characteristics peculiar to man. In six human soleus muscles plus three anomalies, the intramuscular distribution of the nerves supplying these muscles was macroscopically examined. In the normal soleus muscles, the R. anterior supplied not only the portio anterior but also the portio posterior through several anastomoses with twigs of the R. posterior. In the soleus without the portio anterior, the R. anterior entered the muscle at the anterior surface and joined directly with the branches of the R. posterior. In the soleus with two bipenniform parts, one bipenniform part was supplied by the R. anterior, and the other by the R. posterior. The cross-sectional area of the total nerves supplying the muscle was 0.72 +/- 0.036 mm2 (n = 8). The areas of the R. posterior and the R. anterior were in inverse relation to each other. These findings suggest that the R. anterior became separated from the R. posterior. However, the endoperineurium fiber composition of the R. anterior appeared to consist of a few nerve fiber components different from those of the R. posterior.

Cadaver↗

PubMed1991

[Changes in various differentiation-related markers after differentiation induction of a pluripotent human embryonal carcinoma (EC) cell line by hexamethylene bisacetamide].

A pluripotent human EC cell line (NEC14) could be induced to morphologically differentiate by treatment with 10(-2) M HMBA for 3 days in vitro. The changes in various differentiation-related markers (cell surface antigens, lectin binding sites, intermediate filaments, secreted products and extracellular matrix proteins) after induction of differentiation were examined in order to clarify the differentiation lineage. The results were as follows: 1) The most conspicuous changes in cell surface antigens after differentiation were the expression of major human histocompatibility antigens (HLA-A,B,C) and the changes in stage specific embryonic antigens (SSEA-1-/SSEA-3(+)----SSEA-1+/SSEA-3-). 2) Vimentin, mesenchymal intermediate filament, was only detected after the differentiation. 3) Tenascin, an extracellular matrix protein produced in mesenchymal cells, was produced after the differentiation. These results indicate that HMBA can induce NEC14 cells to differentiate into mesenchymal elements of embryonal mesoderm.

Acetamides↗

PubMed1991

[Transforming activity of human papillomavirus 16 DNA].

A HPV16DNA integrated in a human cancer cell line of the uterine cervix (QG-U) was isolated and cloned. Three kinds of cells (mouse Balb/3T3, Detroit 551 and human keratinocyte) were co-transfected with HPV16DNA and neo DNA with calcium phosphate co-precipitates. Selection of the Transformants and their characteristics were examined. Transformants of mouse Balb/3T3 cells were able to be obtained about 2 weeks after co-transfection. HPV16DNA was integrated in the transformants. The most characteristic change observed in the transformants was the ability to proliferate in serum-free medium. In contrast, two kinds of human diploid cells (Detroit 551 and human keratinocyte) were not transformed by transfection, and ceased growing at almost the same time as nontransfected cells. These results indicate that HPV-DNA transformants are easily selected in cell lines rodents but selection of transformants from human diploid cells is relatively difficult.

Animals↗

PubMed1991

[Intramuscular distribution of nerves supplying the soleus muscle in the chimpanzee].

The human soleus muscle is considered a specialized muscle in terms of its origin, insertion and muscle fibre architecture (especially with regard to the existence of the bipenniform part). Its peculiarities have been understood as results of erect posture and bipedal walking (Frey, 1913). Sekiya (1991) pointed out that another feature of the human soleus muscle the nerve supply, i.e. the muscle received two kinds of nerves, the anterior branch (R. anterior) and the posterior branch (R. posterior); the former supplied the bipenniform part at the anterior surface of the muscle and communicated with the R. posterior within the muscle. In nonhuman primates, the soleus muscle has no bipenniform part and the nerve, identical with the R. anterior to the human soleus muscle, is unknown. The purpose of the present study is to clarify the pattern of the nerve supply to the soleus muscle in the chimpanzee, with special reference to the intramuscular distribution of the nerves and to discuss the origin of the R. anterior to the human soleus muscle from a comparative anatomical point of view. Six soleus muscles from three chimpanzees (Pan troglodytes) were examined under a stereomicroscope to clarify the intramuscular distribution of nerves supplying these muscles. The nerves supplying the soleus muscle were classified into three types according to the sites of their entry into the muscle. The first group nerve was the thickest of all nerves innervating the muscle, entered the muscle at the posterior surface of the proximal third and was considered as homologous with the R. posterior in the human.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

[Fundamental studies on differentiation inducers using a human embryonal carcinoma model].

A human embryonal carcinoma (EC) cell line, NEC14, was pluripotent and the tumors formed in nude mice contained differentiated somatic and extra-embryonic elements in addition to EC. The NEC14 cells could be induced to differentiate with 5 differentiation inducers in vitro, and N,N'-hexamethylene bisacetamide (HMBA) showed the most potent differentiator induction among them. All of the NEC14 cells were morphologically differentiated when exposed to 10(-2) M HMBA for 3 days. The differentiated derivatives ceased to proliferate in vitro and became non-tumorigenic in nude mouse. Several differentiation markers appeared in the differentiated derivatives. When the tumor-bearing nude mice were injected intraperitoneally with HMBA (10mg, twice a week), the tumor growth was inhibited. These results show that human EC is a useful model of differentiation-induction in cancer therapy.

Acetamides↗

PubMed1991

[Result of individualized chemotherapy with a newly developed in vitro chemosensitivity testing in ovarian cancer].

By means of a newly developed in vitro chemosensitivity test based on the morphological changes in the nucleus (nuclear damage assay) as previously described, we were able to screen currently available anticancer drugs within 24 hr with a 100% success rate. The nuclear damage assay was used to determine the chemosensitivity in 50 patients (66 assays) with ovarian cancer. The response rate for the 13 patients with measurable tumors, 8 of whom showed resistance to CAP (cyclophosphamide, adriamycin, and cisplatin) therapy, was 46 percent when they were given various combination chemotherapy protocols consisting of more than one active agent selected from group A and B agents by the nuclear damage assay. The newly developed in vitro chemosensitivity test proved to be useful when selecting a second line combination for patients with CAP-resistant ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1991

[Basic study on in vitro chemosensitivity tests].

By means of 3 different kinds of in vitro chemosensitivity testings--(1) a nuclear damage assay developed by us, (2) MTT assay, and (3) colony formation inhibition assay--we examined the sensitivity of 8 kinds of human ovarian cancer cell lines to various anticancer drugs. The sensitivity of in vivo xenografts of the cell lines in nude mice to anticancer drugs was also examined by inhibition of the tumor growth. The in vitro--in vivo correlation of sensitivity was studied in respect to both sensitivity and specificity rates. 1. Different active anticancer drugs were screened among the 3 in vitro chemosensitivity testings in the same human ovarian cancer cell line. 2. The in vitro--in vivo correlation of the nuclear damage assay (sensitivity 50%, specificity 94%) was the highest among the 3 testings. The nuclear damage assay which we developed therefore seemed to be the most useful assay method for clinical use.

Animals↗

PubMed1990

Vascular hyperpermeability induced by tumor necrosis factor and its augmentation by IL-1 and IFN-gamma is inhibited by selective depletion of neutrophils with a monoclonal antibody.

We investigated whether various recombinant cytokines induce vascular hyperpermeability when intradermally injected into rats. Only TNF did so. Of the other cytokines examined (IL-1, IL-2, granulocyte-CSF, IFN-alpha, IFN-beta, IFN-gamma) none had this effect. The increase in vascular permeability was dose dependent, and the peak response was observed at 90 min after TNF injection. When mixtures of TNF and various other cytokines (IL-1, IL-2, granulocyte-CSF, IFN-alpha, IFN-beta, IFN-gamma) were injected, only IL-1 and IFN-gamma augmented TNF-induced vascular hyperpermeability, the increase occurring in a dose-dependent manner. The induction of vascular hyperpermeability by TNF and its enhancement by IL-1 and IFN-gamma were inhibited by selective depletion of peripheral blood neutrophils with i.p. administration of an anti-rat neutrophil mAb, RP-3. Reconstitution of neutrophils to the depleted rats by in situ injection of these cells, restored TNF increased vascular permeability.

Animals↗