Scid mice model for the in-vivo study of human oncotherapy - studies on the growth and metastasis of human lung-cancer

For the study of the growth and metastasis of human lung cancer, we established a severe combined immunodeficient (SCID) mouse model for engraftment of intact human lung-cancer tissue dissected from patient specimens. Small fragments of human lung-cancer tissues (14 cases) obtained from surgery or autopsy were implanted into the mammary fat pads of SCID mice. Seven of the fourteen cases (50%) showed an evident enlargement of the implanted lung-cancer tissue, the histopathology of which was almost identical to that of the original cancer tissues for as long as 2 months following implantation. There was slight correlation between the implantation success rate and the clinical stage of the patient at implantation. A second implantation of cancer tissues on four of these cases was successful. In contrast, no significant enlargement of the implanted tissue was observed in the cases of normal human peripheral-lung tissues (five cases), but a bronchial epidermal feature was observed in all of them. Matrigel (Collaborative Research, Bedford, MA) coating of the tissues significantly increased the growth rate of lung-cancer implants, and a high correlation (R=O.806) between the size of the implanted human lung-cancer tissues and carcinoembryonic antigen levels in the SCID mice was seen. Additionally, human lung-cancer cell lines subcutaneously injected into the backs of mice showed more metastatic lesions in the lungs and lymph nodes of SCID mice than in nude mice. Also, fresh human lung cancer metastasized to the lymph nodes and lungs of SCID mice. The results demonstrate the utility of SCID mice as recipients of human lung-cancer tissue and the applicability of this model to the in vivo study of mechanisms of human lung-cancer growth and metastasis.     

Trypargine blocks the sodium channels only from the inside of squid giant axon

A new tetrahydro-beta-carboline, trypargine (TRG), specifically suppresses the Na current (INa) when applied to the internal surface of the squid axon membrane without affecting the K current (IK). The binding of TRG to its receptor is potential-dependent and occurs at a site about halfway through the membrane electric field from the outside; the dissociation constant is 11 microM at 0 mV.     

Effects of hyperin, isoquercitrin and quercetin on lipopolysaccharide-induced nitrite production in rat peritoneal macrophages

The extract of the root of Acanthopanax chiisanensis Nakai is used for the treatment of inflammation. To analyse the action mechanism of this extract, the effect of hyperin (quercetin-3-O-beta-d-galactose) isolated from the ethyl acetate fraction of the root of A. chiisanensis on nitrite production and induction of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS, 1 microg/mL)-stimulated rat peritoneal macrophages were examined. The effect of the structurally related compounds, isoquercitrin (quercetin-3-O-beta-d-glucose) and quercetin (an aglycone of the two compounds) isolated from the extract of the leaves of Vaccinium koreanum Nakai was also examined to compare the effect. It was shown that hyperin inhibited the LPS-induced iNOS expression and nitrite production. Of the three compounds, quercetin showed the most potent inhibitory activity. The phosphorylation of p44/42 mitogen activated protein kinase (MAPK), p38 MAPK and c-Jun N-terminal kinase (JNK) were also inhibited by these compounds. These findings suggested that hyperin in the extract of the root of A. chiisanensis inhibits nitric oxide (NO) production through inhibition of the expression of iNOS by attenuation of p44/p42 MAPK, p38 MAPK and JNK, and thus participates in the antiinflammatory activity of the extract.     

Alpha 1-antitrypsin genes in patients with alpha 1AT deficiency in Japan: mutational analysis and allelic background]

Deficiency of alpha 1-antitrypsin (alpha 1AT), a plasma serine protease inhibitor, increases the risk of precocious pulmonary emphysema. Patients with alpha 1AT deficiency in Japan are extremely rare and no Z type alpha 1AT deficiency, which is one of the most frequent genetic disorders among Caucasians, are reported in Japan at the level of gene analysis. It is not yet clear why Z type alpha 1AT is rare among Japanese. When Ala213(GCG)-Val213(GTG) mutation in the alpha 1AT gene was examined by restriction endonuclease BstPI, all of 156 Japanese samples were Val213(GTG) in contrast to the finding that 30% of U.S. Caucasians are Ala213(GCG), indicating that alpha 1AT genes among Japanese were diverted from M1(Val213) variant and are different from M1(Ala213) variant, from which Z variant was likely diverted. This may explain why Z type alpha 1AT deficiency is not found among Japanese. A new alpha 1AT deficient variant, Siiyama (Ser53(TCC)-Phe53(TTC)), was found in a 39-year-old male with pulmonary emphysema (Seyama K, et al, J Biol Chem, 266, 12627, 1991). Interestingly, 6 out of 10 families with alpha 1AT deficiency in Japan shared the identical substitution as Siiyama. This indicates that although Caucasian type Z alpha 1AT deficiency is not found, Siiyama variant may be relatively common in Japan and even in other oriental countries because of the historical migration of people.     

Variation of increases in free cytosolic calcium ion induced by prostaglandin E2 in mouse osteoblast clone,MC3T3-E1—Single cell assay using microspectro-fluorometry

Osteoblasts exhibit multiple phenotypic expression in response to prostaglandin E₂ (PGE₂). Intracellular calcium concentration ([Ca²⁺] _i ) was elevated by PGE₂ treatment in the mouse osteoblast clone, MC3T3-E1, but the degree of elevation was varied by the day after subculturing. To study the different response to PGE₂, we have used microspectrofluorometry to measure [Ca²⁺] _i in a single MC3T3-E1 cell loaded with fura-2. In the presence of extracellular Ca²⁺, the increase in [Ca²⁺] _i in the osteoblast exhibited multiple patterns. The patterns were roughly classified into four groups by the time reached maximum level; “transient”, “gradual”, “transient and gradual” and “no response”. Within 2 days after subculturing, the cells showing “gradual” and “no response” were predominant, whereas after day 3 the cells showing “transient” and “transient and gradual” were predominant. We also investigated the daily change in the maximum level of [Ca²⁺] _i in the cells showed “transient” in response to PGE₂. The magnitude of [Ca²⁺] _i increase was also varied in cultivating period. These data suggest that there are phenotypic variations in a single cell even in a cloned cell line and this phenotype may change in the stage of cell proliferation.     

Lymphangiogenesis-mediated shedding of LAM cell clusters as a mechanism for dissemination in lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) affects exclusively women of reproductive age, involves the lungs and axial lymphatic system, and is frequently complicated with renal angiomyolipomas. LAM lesions are generated by the proliferation of LAM cells with mutations of one of the tuberous sclerosis complex (TSC) genes. Recent studies indicate that LAM cells can migrate or metastasize to form new lesions in multiple organs, although they show a morphologically benign appearance. In the previous study, we reported LAM-associated lymphangiogenesis and implicated its role in the progression of LAM. In this study, we further focused on the lymphatic abnormalities in LAM: LAM-associated chylous fluid (5 pleural effusion and 2 ascites), surgically resected diaphragm (1 patient), and axial lymphatic system including the thoracic duct, lymph nodes at various regions, and diaphragmatic lymphatic system (5 autopsy cases). We demonstrated that LAM cell clusters enveloped by lymphatic endothelial cells (LCC) in all chylous fluid examined. We identified LAM lesion in the diaphragm (2 of 5 autopy cases and one surgical specimen), thoracic duct (5 of 5), and lymph nodes (retroperitoneal (5 of 5), mediastinal (4 of 5), left venous angle (5 of 5) with total positive rate of 68% to 88% at each region of the lymph node, but less frequent or none at remote lymph nodes located away from the axial lymph trunk (cervical [1 of 5] and axillary [0 of 5]). LCCs were identified in intra-LAM lesional lymphatic channels where LAM cells proliferate along lymphatic system. In in vitro culture system, LCC can fragment into each proliferating LAM cell. These findings suggest that LAM-associated lymphangiogenesis demarcates LAM lesion into bundle- or fascicle-like structure and eventually shed LCC into the lymphatic circulation and that LCCs play a central role in the dissemination of LAM lesion.