Cholesterol and hydroxycholesterol sulfotransferases: identification, distinction from dehydroepiandrosterone sulfotransferase, and differential tissue expression

In humans, the biotransformation of cholesterol and its hydroxylated metabolites (oxysterols) by sulfonation is a fundamental process of great importance. Nevertheless, the sulfotransferase enzyme(s) that carries out this function has never been clearly identified. Cholesterol is a relatively poor substrate for the previously cloned hydroxysteroid sulfotransferase (HST), i.e. dehydroepiandrosterone (DHEA) sulfotransferase (HST1). Recently, cloning of a single human gene that encodes for two proteins related to HST1 was reported. These newly cloned sulfotransferases (HST2a and HST2b), while exhibiting sequence similarity to other members of the soluble sulfotransferase superfamily, also contain unique structural features. This latter aspect prompted an examination of their substrate specificity for comparison with HST1. Thus, HST1, HST2a, and HST2b were overexpressed as fusion proteins and purified. Furthermore, a novel procedure for the isolation of cholesterol and oxysterol sulfonates was developed that was used in association with HPLC to resolve specific sterol sulfonates. HST1 preferentially sulfonated DHEA and, to a lesser extent, oxysterols; whereas cholesterol was a negligible substrate. The reverse, however, was the case for the HST2 isoforms, particularly HST2b, which preferentially sulfonated cholesterol and oxysterols, in contrast to DHEA, which served as a poor substrate for this enzyme. RT-PCR analysis revealed distinct patterns of HST1, HST2a, and HST2b expression. It was particularly notable that both HST2 isoforms, but not HST1, were expressed in skin, a tissue where cholesterol sulfonation plays an important role in normal development of the skin barrier. In conclusion, substrate specificity and tissue distribution studies strongly suggest that HST2a and HST2b, in contrast to HST1, represent normal human cholesterol and oxysterol sulfotransferases. Furthermore, this study represents the first example of the sulfonation of oxysterols by a specific human HST.

Transcriptional regulation of human 3'-phosphoadenosine 5'-phosphosulfate synthase 1

Sulfonation, which is essential for normal growth, development and maintenance of the internal milieu, requires the universal sulfonate donor molecule 3'-phosphoadenosine 5'-phosphosulfate (PAPS) produced from ATP and inorganic sulfate by two bifunctional PAPS synthase isozymes. The gene for PAPS synthase 1 containing neither a TATA nor a CCAAT box was found to be under the influence of the Sp1 family of transcription factors. Multiple GC/GT boxes are present in the proximal promoter region and deletion analysis implicated their involvement in transcription, a finding supported by mutational analysis of specific GC/GT boxes. Nuclear extract of SW13 cells, which highly express PAPS synthase 1, contains proteins that bind to probes possessing specific GC/GT boxes; furthermore, the presence of Sp1, Sp2, and Sp3 proteins in nuclear extracts was confirmed by supershift analysis. Cotransfection experiments using SL2 cells yielded additional support for the involvement of Sp1 in transcriptional regulation of the PAPS synthase 1 gene; the involvement of Sp2 and/or Sp3 is presently unclear.

Hemolymph analysis and evaluation of newly formulated media for culture of shrimp cells (Penaeus stylirostris)

Creation of a shrimp cell line has been an elusive goal. This failure may be due to the composition of the cell culture medium, which may be inadequate to support primary cultured cells. Shrimp hemolymph should contain the nutritional components needed to support cell growth and division. We report here the comprehensive biochemical analysis of hemolymph from the blue shrimp, Penaeus stylirostris (Litopenaeus stylirostris) (see Holthuis, L. B. Shrimps and prawns of the world, in: FAO species catalog. Vol. 1. Rome: Food and Agriculture Organization of the United Nations; 1980), for free amino acids (FAAs), carbohydrates, electrolytes, metals, pH, and osmolality. Levels of hemolymph components were compared to 2xL-15 with 20% fetal bovine serum, a commonly used culture medium for crustacean cells. The FAAs, taurine and proline, and the metals, strontium and zinc, were significantly higher in hemolymph than in the 2 x L-15 medium. In contrast, other FAAs were up to 50 times higher in the 2 x L-15 medium than in the hemolymph. To mimic more closely the hemolymph composition, we created two new media based on either the 0.2 x L-15 or the M199 medium. We compared the microscopic appearance of cells cultured in these media and evaluated deoxyribonucleic acid (DNA) and protein synthesis by 3H-thymidine uptake and 35S-methionine uptake assays. The ovary cells of P. stylirostris cultured in either of the new media formed monolayers, while the cells cultured in 2 x L-15 medium did not. Despite these differences, there was no evidence of sustained DNA or protein synthesis with any of the media. Future studies to establish a shrimp cell line should focus on analysis of the cell cycle and on overcoming the molecular blocks to cell division.

Involvement of the cholinergic pathway in the pathogenesis of pituitary Cushing's syndrome

Transsphenoidal adenomectomy is currently the first choice for treatment of patients with pituitary ACTH-dependent Cushing's syndrome. However, pharmacotherapy is prescribed for some patients, e.g., unsuccessful surgery. We treated a woman in whom pituitary Cushing's syndrome was improved while she was on antimuscarinic cholinergic agents, atropine sulphate and pirenzepine hydrochloride. The diminished effect of anticholinergics on ACTH and cortisol was incidentally identified in an inferior petrosal sinus sampling procedure. A single intramuscular injection of atropine significantly decreased both ACTH (43.9 pg/ml to less than 12.0; normal, 12.0-40.0 pg/ml) and cortisol (29.9 microg/dl to 13.6; normal, 7.6-23.6 microg/dl). An M1-muscarinic receptor specific antagonist, pirenzepine hydrochloride, also had a diminishing effect on these hormones and this inhibiting effect was partially blocked by the simultaneous administration of an anticholinesterase agent, pyridostigmine bromide. Chronic oral ingestion of these agents led to improvement in clinical symptoms, and urinary 17-hydroxycorticosteroid and 17-ketosteroid levels were at normal to upper-normal levels. This is the first documentation of involvement of the cholinergic system in the pathogenesis of pituitary Cushing's syndrome.

Acute hepatitis C among Japanese hemodialysis patients: a prospective 9-year study

OBJECTIVES

The aims of this prospective survey were to determine the incidence and clinical characteristics of newly acquired hepatitis C virus (HCV) infection in hemodialysis patients after the start of antibody to HCV (anti-HCV) screening for blood products in Japan in 1989.

METHODS

In serial serum samples from 269 hemodialysis patients who were followed over a mean period of 6.6 yr (+/- 2.1 yr) from 1990 to 1998, HCV RNA and anti-HCV were detected by reverse transcription-polymerase chain reaction and second generation ELISA, respectively.

RESULTS

During the observation period, newly acquired HCV infection was found in 26 (15.4%) of the 169 hemodialysis patients without anti-HCV or HCV RNA at entry, an annual incidence rate of 2.59%. Of these 26, only four had a history of blood transfusion, one of whom had received the blood transfusion after 1992, the year in which screening of blood products for anti-HCV by second-generation ELISA was introduced in Japan. Persistent HCV viremia was found in 17 (65.4%) of the 26 patients; the other nine (34.6%) had transient HCV infection. The mean period of continuous ALT abnormality was significantly longer in the former (12.4+/-13.6 months) than in the latter (1.9+/-3.5 months) (p = 0.0067). However, only three (17.6%) of 17 patients with chronic HCV viremia had continuous ALT abnormality for more than 24 months; in all of them, ALT eventually normalized.

CONCLUSIONS

These findings indicate that newly acquired HCV infection has continued to occur in hemodialysis patients after the initiation of anti-HCV screening of blood products and that the abnormal ALT found in these patients is related to HCV chronicity.

Differences in estrogen receptor status, HER2, and p53 comparing metachronous bilateral breast carcinoma

BACKGROUND AND OBJECTIVES

We analyzed the clinicopathologic characteristics and tumor biology of metachronous bilateral breast carcinoma with regard to p53, HER2 and hormone receptor status.

METHODS

A consecutive series of 54 female metachronous bilateral breast carcinoma patients treated at the National Cancer Center Hospital between 1980 and 1997 were the primary source of these retrospective data. Clinicopathologic background factors were analyzed, and immunohistochemical staining for p53, HER2, and hormone receptor status was carried out on paraffin-embedded specimens.

RESULTS

There were no significant differences in clinical stage, p53 and HER2 expression levels between the first and second primary tumors. The positive rates for ER and PR were 48% (25 of 52) and 46% (25 of 54) for the first tumors, but only 19% (10 of 52) and 32% (17 of 54) for the second tumors (P = 0.004 for ER, P = 0.16 for PR), showing a significant loss of ER.

CONCLUSIONS

Our findings indicate that p53 and HER2 expression levels in the second tumors might be the same as those of the first tumors in metachronous bilateral breast carcinoma; however, loss of ER was more frequently observed in the second primary tumors than in the first tumors.

Multicentricity and histopathological background features of familial breast cancers stratified by menopausal status

BACKGROUND

We investigated histopathological background and multicentricity in patients with familial breast cancers (FBCs) in comparison with these features in patients with sporadic breast cancers (SBCs), stratifying patients by menopausal status.

METHODS

We collected a consecutive series of 469 FBC patients and 3334 SBC patients treated at our hospital between 1965 and 1995. The following criteria were used to define FBC, regardless of the presence or absence of a family history of other cancer or the patient's past history of malignancies: (1) Three or more second-degree relatives had been affected by breast cancer; (2) two first-degree relatives had been affected by breast cancer, and either one of them was under 40 years of age and/or had had bilateral breast cancers. The presence or absence of background proliferative lesions (PL; ductal/lobular hyperplasia and/or adenosis) and the multicentricity of breast carcinomas in FBCs and SBCs were analyzed for each group.

RESULTS

In premenopausal FBC patients, there was a non-significant trend towards a high frequency of multicentricity compared with findings in patients with SBCs overall (P = 0.087; odds ratio [OR], 1.43; 95% confidence interval [CI], 0.96-2.13). In premenopausal FBC patients, the frequency of background proliferative lesions with/or without fibroadenomas (FA) in the resected specimen was significantly higher than that in SBC patients overall (P = 0.001 for PL; OR, 1.47; 95% CI, 1.18-1.83; P < 0.001 for PL +/- FA; OR, 6.84; 95% CI, 4.93-9.49). With regard to the other clinicopathological factors examined, there were no significant differences between the two groups, except for the higher frequency of premenopausal patients among the FBC patients.

CONCLUSION

These results indicate that premenopausal patients with FBCs had more proliferative lesions in the histopathological background and more multicentric breast cancers than premenopausal patients with SBCs.

Interleukin-6 (IL-6) producing phaeochromocytoma: direct IL-6 suppression by non-steroidal anti-inflammatory drugs

A 35-year-old Japanese woman presented with a phaeochromocytoma and demonstrated marked inflammatory reactions and pyrexia as a result of excessive production of interleukin-6 (IL-6) by the tumour. Serum IL-6 level was 262 ng/l (normal; < 4.0 ng/l). Fever and inflammatory markers were largely overcome by the administration of the nonsteroidal anti-inflammatory drug, naproxen, and all symptoms disappeared soon after the tumour was excised. Immunohistochemical study revealed positive staining using an antihuman IL-6 antibody and Northern analysis showed increased IL-6 mRNA levels in the tumour. Cultured tumour cells showed IL-6 protein synthesis, and nonsteroidal anti-inflammatory drugs such as naproxen and indomethacin directly inhibited IL-6 release. These results indicate that the effects of naproxen in vivo were due, at least in part, to direct suppression of IL-6 secretion from the tumour.

[A survey of awareness among new patients at the department of oral diagnosis and general dentistry]

The purpose of this study is to know the outline of clinical statistics of new patients at the Clinic for Initial Diagnosis/Emergency, Dental Hospital, Tokyo Medical and Dental University. We examined 1,001 new patients who visited our hospital from 19 October to 8 December 1995. The results were obtained as follows: 1. Our subjects were 1,001 patients, males were 357(35.7%) and females 644(64.3%). The ratio of male to female was 1:1.8. 2. Concerning age distribution, the majorities were in their twenties and fifties in order. 3. 71.5% of patients said it took less than one hour for them to come to our hospital. 4. The rate of introduced patients was 5.5% of all the new patients.

Inhibition of tumor metastasis by adoptive transfer of IL-12-activated Valpha14 NKT cells

A unique lymphocyte lineage, the Valpha14 NKT cells, expresses both NK1.1 and an invariant antigen receptor encoded by Valpha14 and Jalpha281 gene segments. Valpha14 NKT cells play crucial roles in various immune responses, including autoimmune diseases, allergic reactions and anti-tumor immunity. Valpha14 NKT cells were demonstrated to be essential for anti-tumor effect of IL-12 in vivo. Here, we report that adoptive transfer of IL-12-activated Valpha14 NKT cells prevents hepatic metastasis of B16 melanoma. The injection of large amounts of IL-2, IL-4, and IFN-gamma, which are cytokines produced by activated Valpha14 NKT cells, exhibited no significant inhibition of the metastasis of this melanoma. The cells prepared from the liver of IL-12-injected mice expressed a potent cytotoxic activity on B16 melanoma cells in vitro. Although the adoptive transfer of IL-12-activated Valpha14 NKT cells prevents hepatic metastasis of B16 melanoma, activated NK cells from IL-12-injected RAG-1-/- mice failed to inhibit the metastasis of this melanoma. Thus, the anti-tumor effect of IL-12 can be replaced by adoptive transfer of IL-12-activated Valpha14 NKT cells but not by IL-12-activated NK cells, suggesting a minor role of NK cells for the IL-12-mediated anti-tumor effect in this experimental system. Moreover, our studies have suggested the involvement of direct cytotoxic mechanisms rather than cytokine-mediated immune responses at the effector phase of the Valpha14 NKT cell-mediated anti-tumor activity.

Progression of T cell lineage restriction in the earliest subpopulation of murine adult thymus visualized by the expression of lck proximal promoter activity

The proximal promoter of lck directs gene expression exclusively in T cells. To investigate the developmental regulation of the lck proximal promoter activity and its relationship to T cell lineage commitment, a green fluorescence protein (GFP) transgenic (Tg) mouse in which the GFP expression is under the control of the proximal promoter of lck was created. In the adult GFP-Tg mice, >90% of CD4(+)CD8(+) and CD4(+)CD8(-) thymocytes, and the majority of CD4(-)CD8(+) and CD4(-)CD8(-) [double-negative (DN)] thymocytes were highly positive for GFP. Slightly lower but substantial levels of expression of GFP was also observed in mature splenic T cells. No GFP(+) cells was detected in non-T lineage subsets, including mature and immature B cells, CD5(+) B cells, and NK cells, indicating a preserved tissue specificity of the promoter. The earliest GFP(+) cells detected were found in the CD44(+)CD25(-) DN thymocyte subpopulation. The developmental potential of GFP(-) and GFP(+) cells in the CD44(+)CD25(-) DN fraction was examined using in vitro culture systems. The generation of substantial numbers of alphabeta and gammadelta T cells as well as NK cells was demonstrated from both GFP(-) and GFP(+) cells. However, no development of B cells or dendritic cells was detected from GFP(+) CD44(+)CD25(-) DN thymocytes. These results suggest that the progenitors expressing lck proximal promoter activity in the CD44(+)CD25(-) DN thymocyte subset have lost most of the progenitor potential for the B and dendritic cell lineage. Thus, progression of T cell lineage restriction in the earliest thymic population can be visualized by lck proximal promoter activity, suggesting a potential role of Lck in the T cell lineage commitment.

The role of alpha-galactosylceramide-activated Valpha14 natural killer T cells in the regulation of Th2 cell differentiation

Valpha14 natural killer T (NKT) cells produce large amounts of both IL-4 and IFN-gamma upon stimulation with a ligand, alpha-galactosylceramide (alpha-GalCer), and play a crucial role in various immune responses, including allergic diseases. Interestingly, Valpha14 NKT cells are not essential for the induction of IgE responses but rather induce suppression of specific IgE production upon activation. The suppression in the IgE production is not detected either in Valpha14 NKT cell-deficient mice or in IFN-gamma-deficient mice. Thus, activated Valpha14 NKT cells are likely to exert a potent suppressive activity on Th2 cell differentiation and subsequent IgE production by producing a large amount of IFN-gamma. In marked contrast, little regulatory effect of IL-4 produced by Valpha14 NKT cells on Th2 cell differentiation is suggested.

Infectious hypodermal and hematopoietic necrosis virus of shrimp is related to mosquito brevidensoviruses

We purified and sequenced infectious hypodermal and hematopoietic necrosis virus (IHHNV), a small DNA virus of shrimp, from wild Penaeus stylirostris. The virion has a buoyant density of 1.45 as determined by cesium chloride gradient. Analysis of 3873 nucleotides of the viral genome revealed three large open reading frames (ORFs) and parts of the noncoding termini of the viral genome. The left, mid, and right ORFs on the complementary (plus) strand have potential coding capacities of 666 amino acids (aa) (75.77 kDa), 363 aa (42.11 kDa), and 329 aa (37.48 kDa), respectively. The overall genomic organization is similar to that of the mosquito brevidensoviruses. The left ORF most likely encodes the major nonstructural (NS) protein (NS-1) since it contains conserved replication initiator motifs and NTP-binding and helicase domains similar to those in NS-1 from all other parvoviruses. The IHHNV putative NS-1 shares the highest aa sequence homology with the NS-1 of mosquito brevidensoviruses, Aedes densovirus and Aedes albopictus parvovirus. A search for putative splicing sites revealed that the N-terminal region of NS-1 is very likely located in a small ORF upstream of the left ORF. The right ORF is presumed to encode structural polypeptides (VPs), as in other parvoviruses. Two putative promoters, located upstream of the left and right ORFs, are presumed to regulate expression of NS and VP genes, respectively. Thus, IHHNV is closely related to densoviruses of the genus Brevidensovirus in the family Parvoviridae, and we therefore propose to rename this virus Penaeus stylirostris densovirus (PstDNV).

Reconstruction of the anterior cruciate ligament using a double bundle

We developed a reconstruction technique for the anterior cruciate ligament using a double bundle that is the combination of bone-tendon-bone (BTB) from the patellar tendon and semitendinosus tendon (ST). BTB is fixed in the tunnels produced on the isometric points on the tibia and femur. ST is fixed on the tibial tunnel through the same route as the BTB, but on the femur, through the over-the-top route, which is located posterolateral to the femoral tunnel. Use of this double bundle realizes a physiologically more durable reconstruction because BTB corresponds to the anteromedial bundle of the ACL and ST corresponds to the posterolateral bundle, and these produce 2 different tension patterns within the bundle. This technique is also applicable to revision surgeries for patients with an extended bone loss on the tibia.

Changes in findings of mammography, ultrasonography and contrast-enhanced computed tomography of three histological complete responders with primary breast cancer before and after neoadjuvant chemotherapy: case reports

We report the changes in the findings of imaging examinations (mammography, ultrasonography and contrast-enhanced computed tomography) of three patients with primary breast cancer before and after neoadjuvant chemotherapy, who obtained histologically complete responses after the chemotherapy. The neoadjuvant chemotherapy consisted of four cycles of doxorubicin and docetaxel. All patients were clinically judged as partial responders, because of the remaining tumorous lesions in the imaging examinations. However, these tumorous lesions could be related to the chemotherapy-induced fibrosis and tumor necrosis or the remaining fibrocystic changes. In this study, it was considered very difficult to estimate the extent of residual tumors accurately in patients with primary breast cancer after neoadjuvant chemotherapy by any type of imaging examination.

Alternate exon in the 5'-untranslated region of the human ACTH receptor gene

The human ACTH receptor (ACTH-R) gene consists of two exons; the first encodes the 5'-untranslated region (UTR) and the second encodes part of the 5'-UTR, the entire coding region, and the whole of the 3'-UTR. While investigating the transcription initiation site of the human ACTH-R gene by 5'-rapid amplification of cDNA ends, we found a 157-bp alternate exon in the 5'-UTR. This newly identified exon was irrelevant to the alternate exon in the mouse ACTH-R gene which we reported previously.

Kawasaki disease: A brief history

Tomisaku Kawasaki published the first English-language report of 50 patients with Kawasaki disease (KD) in 1974. Since that time, KD has become the leading cause of acquired heart disease among children in North America and Japan. Although an infectious agent is suspected, the cause remains unknown. However, significant progress has been made toward understanding the natural history of the disease and therapeutic interventions have been developed that halt the immune-mediated destruction of the arterial wall. We present a brief history of KD, review progress in research on the disease, and suggest avenues for future study. Kawasaki saw his first case of KD in January 1961 and published his first report in Japanese in 1967. Whether cases existed in Japan before that time is currently under study. The most significant controversy in the 1960s in Japan was whether the rash and fever sign/symptom complex described by Kawasaki was connected to subsequent cardiac complications in a number of cases. Pathologist Noboru Tanaka and pediatrician Takajiro Yamamoto disputed the early assertion of Kawasaki that KD was a self-limited illness with no sequelae. This controversy was resolved in 1970 when the first Japanese nationwide survey of KD documented 10 autopsy cases of sudden cardiac death after KD. By the time of the first English-language publication by Kawasaki in 1974, the link between KD and coronary artery vasculitis was well-established. KD was independently recognized as a new and distinct condition in the early 1970s by pediatricians Marian Melish and Raquel Hicks at the University of Hawaii. In 1973, at the same Hawaiian hospital, pathologist Eunice Larson, in consultation with Benjamin Landing at Los Angeles Children's Hospital, retrospectively diagnosed a 1971 autopsy case as KD. The similarity between KD and infantile periarteritis nodosa (IPN) was apparent to these pathologists, as it had been to Tanaka earlier. What remains unknown is the reason for the simultaneous recognition of this disease around the world in the 1960s and 1970s. There are several possible explanations. KD may have been a new disease that emerged in Japan and emanated to the Western World through Hawaii, where the disease is prevalent among Asian children. Alternatively, KD and IPN may be part of the spectrum of the same disease and clinically mild KD masqueraded as other diseases, such as scarlet fever in the preantibiotic era. Case reports of IPN from Western Europe extend back to at least the 19th century, but, thus far, cases of IPN have not been discovered in Japan before World War II. Perhaps the factors responsible for KD were introduced into Japan after the World War II and then reemerged in a more virulent form that subsequently spread through the industrialized Western world. It is also possible that improvements in health care and, in particular, the use of antibiotics to treat infections caused by organisms including toxin-producing bacteria reduced the burden of rash/fever illness and allowed KD to be recognized as a distinct clinical entity. Itsuzo Shigematsu, Hiroshi Yanagawa, and colleagues have conducted 14 nationwide surveys in Japan. These have indicated that: 1) KD occurred initially in nationwide epidemics but now occurs in regional outbreaks; 2) there are approximately 5,000 to 6,000 new cases each year; 3) current estimates of incidence rates are 120 to 150 cases per 100,000 children <5 years old; 4) KD is 1.5 times more common in males and 85% of cases occur in children <5 years old; and 5) the recurrence rate is low (4%). In 1978, David Morens at the Centers for Disease Control and Prevention published a case definition based on Kawasaki's original criteria. The Centers for Disease Control and Prevention developed a computerized database in 1984, and a passive reporting system currently exists in 22 states. Regional investigations and national surveys suggest an annual incidence of 4 to 15 cases per 100 000 children <5 years o

Impaired Ca/calcineurin pathway in in vivo anergized CD4 T cells

Clonal anergy is one of the mechanisms that may account for self tolerance induced in T cells in the periphery. In this study we used the well-documented system of in vivo administration of a superantigen, staphylococcal enterotoxin B (SEB), to induce a state of hyporesponsiveness (anergy) in murine peripheral T cells to decipher the intracellular biochemical basis for this process. The TCR-induced Ca response of in vitro activated T cells was found to be impaired with significant defects in the phosphorylation of phospholipase C-gamma 1. Experiments with calcium ionophore and newly established transgenic mouse lines that express an active form of calcineurin suggested that in vivo SEB-induced anergy is established and/or maintained by a selective impairment in the TCR-induced activation of the Ca/calcineurin pathway.

Infection of cultured embryo cells of the pacific oyster, Crassostrea gigas, by pantropic retroviral vectors

The inability to stably introduce and express foreign genes has hampered basic research in molluscan species. We cultured cells from dissociated embryos of the Pacific oyster, Crassostrea gigas, and infected these primary cultures with pantropic retroviral vectors containing the envelope glycoprotein of vesicular stomatitis virus. Luciferase transgene expression mediated by different heterologous promoters was demonstrated for at least 9 d after infection of the cells. Surprisingly, the promoter reproducibly mediating the highest level of luciferase expression was the retroviral promoter (U3 region of long terminal repeat) from the Moloney murine leukemia virus. The infection efficiency using a low multiplicity of infection (0.05) was estimated by quantitative polymerase chain reaction to be between 0.1-0.5%. This system will facilitate studies of gene expression and regulation and should be widely applicable to other molluscan species.

c-erbB-2 protein overexpression and p53 immunoreaction in primary and recurrent breast cancer tissues

BACKGROUND AND OBJECTIVES

We investigated whether expression levels of c-erbB-2 and p53 proteins in breast cancer tissues differ in primary and metastatic lesions.

METHODS

Immunohistochemical staining or sandwich enzyme immunoassay was used to determine expression levels of c-erbB-2 and p53 proteins in 42 breast cancer samples from 21 patients. Estrogen (ER) and progesterone receptors (PgR) were also measured by enzyme immunoassay in each case. All patients had undergone radical surgery for primary tumors and surgical resection of asynchronous metastatic lesions. Thirteen patients (62%) were premenopausal and 14 (67%) received postoperative adjuvant therapies. Median disease-free survival time was 26 months (range, 5-104). The resected metastatic lesions included 1 in the liver, 3 in the lung, and 3 in the supraclavicular lymph nodes. The remaining 14 were local skin lesions.

RESULTS

There was no difference in the positivity rate of c-erbB-2 (38%: 8/21) and p53 (39%: 7/18) expression between the primary tumors and the recurrent lesions. In addition, no discordant c-erbB-2 or p53 expression was observed between the primary tumors and their respective metastatic lesions. Positivity rates for ER and PgR were 50% (10/20) and 60% (12/20) for the primary tumors, but only 25% (5/20) and 30% (6/20) for the recurrent lesions, respectively (P = 0. 19 for ER and P = 0.11 for PgR).

CONCLUSIONS

c-erbB-2 and p53 expression levels in breast cancer cells were almost unchanged as the disease progressed and/or in response to adjuvant therapies, regardless of the hormone receptor status.

Identification of amino acid sequence in the hinge region of human vitamin D receptor that transfers a cytosolic protein to the nucleus

The localization of human vitamin D receptor (VDR) in the absence of its ligand 1,25-dihydroxyvitamin D(3) was investigated using chimera proteins fused to green fluorescent protein (GFP) at either the N or C terminus, and the nuclear localization signal (NLS) was identified. Plasmids carrying the fusion proteins were transiently or stably introduced into COS7 cells, and the subcellular distribution of the fusion proteins was examined. GFP-tagged wild-type VDRs were located predominantly in nuclei but with a significant cytoplasmic presence, while GFP alone was equally distributed throughout the cells. 10(-8) M 1,25-dihydroxyvitamin D(3) promoted the nuclear import of VDR in a few hours. To identify the NLS, we constructed several mutated VDRs fused to GFP. Mutant VDRs that did not bind to DNA were also localized predominantly in nuclei, while the deletion of the hinge region resulted in the loss of preference for nucleus. A short segment of 20 amino acids in the hinge region enabled cytoplasmic GFP-tagged alkaline phosphatase to translocate to nuclei. These results indicate that 1) VDR is located predominantly in nuclei with a significant presence in cytoplasm without the ligand and 2) an NLS consisting of 20 amino acids in the hinge region facilitates the transfer of VDR to the nucleus.