A Novel Small-Molecule Inhibitor of Transforming Growth Factor β Type I Receptor Kinase (SM16) Inhibits Murine Mesothelioma Tumor Growth In vivo and Prevents Tumor Recurrence after Surgical Resection

Malignant mesothelioma is an aggressive and lethal pleural cancer that overexpresses transforming growth factor beta (TGFbeta). We investigated the efficacy of a novel small-molecule TGFbeta type I receptor (ALK5) kinase inhibitor, SM16, in the AB12 syngeneic model of malignant mesothelioma. SM16 inhibited TGFbeta signaling seen as decreased phosphorylated Smad2/3 levels in cultured AB12 cells (IC(50), approximately 200 nmol/L). SM16 penetrated tumor cells in vivo, suppressing tumor phosphorylated Smad2/3 levels for at least 3 h following treatment of tumor-bearing mice with a single i.p. bolus of 20 mg/kg SM16. The growth of established AB12 tumors was significantly inhibited by 5 mg/kg/d SM16 (P < 0.001) delivered via s.c. miniosmotic pumps over 28 days. The efficacy of SM16 was a result of a CD8+ antitumor response because (a) the antitumor effects were markedly diminished in severe combined immunodeficient mice and (b) CD8+ T cells isolated from spleens of mice treated with SM16 showed strong antitumor cytolytic effects whereas CD8+ T cells isolated from spleens of tumor-bearing mice treated with control vehicle showed minimal activity. Treatment of mice bearing large tumors with 5 mg/kg/d SM16 after debulking surgery reduced the extent of tumor recurrence from 80% to <20% (P < 0.05). SM16 was also highly effective in blocking and regressing tumors when given p.o. at doses of 0.45 or 0.65 g/kg in mouse chow. Thus, SM16 shows potent activity against established AB12 malignant mesothelioma tumors using an immune-mediated mechanism and can significantly prevent tumor recurrence after resection of bulky AB12 malignant mesothelioma tumors. These data suggest that ALK5 inhibitors, such as SM16, offer significant potential for the treatment of malignant mesothelioma and possibly other cancers.

Intratracheal inoculation of severe acute respiratory syndrome coronavirus in monkeys Macaca rhesus

An animal model for infection with Severe acute respiratory syndrome coronavirus (SARSCoV) was evaluated in monkeys Macaca rhesus. The monkeys were inoculated into the trachea with NS-I strain of SARS-CoV and the clinical manifestation of the illness was monitored. The clinical samples collected from infected monkeys were examined by immumnofluorescence assay (IFA), pathological inspection, RTPCR, and by virus isolation. The infected animals demonstrated mild clinical symptoms including fever. Two of the six infected monkeys developed fever (1.5 above the level before challenge) on the day 10 post inoculation (p.i.). Although the severe clinical symptoms or mortality were not observed, the virological and histopathological evidences of the illness were evident. The specimens collected from the infected animals showed the presence of SARS-CoV detected by RT-PCR, IFA, and by virus isolation. From the organs examined postmortem, a major pathological change was observed in the lungs. The walls of the alveoli were thicker, infiltrated with inflammation cells and an exudative fluid was found in the alveolar spaces. In addition, some alveolar spaces showed hyaline membrane lining. The results showed that the monkeys infected with SARS-CoV developed the typical SARS according to clinical, virological, and pathological findings.

[Effect of Fuzheng Jiangan formula on liver fibrosis induced by albumin in rats]

OBJECTIVE

To observe the effect of Fuzheng Jiangan formula( FZJGF) on liver fibrosis using immune induced liver fibrosis rat model.

METHOD

The rat models with immunity liver fibrosis were induced by the human serum albumin. Rats were treated with normal saline, FZJGF (9. 85,39. 4 g x kg(-1) , two dosage groups) and Colchicine (0. 000 1 g . kg(-1) ). The activities of ALT, AST, contents of ALB and TP, and A/G, The contents of Laminin (LN), Hyaluronic acid (HA) and collagen type IV (IV-C) in rat serum were measured by radioimmunoassay method. The level of hydroxyproline (Hyp) in liver was detected by chemistry method. The pathological changes of liver tissue were observed by HE and Von-Gieson staining.

RESULT

FZJGF could significant decrease the serum activities of ALT and AST, and increase the levels of TP,Alb and ratio A/G. The levels of LN, HA and IV-C were decreased significantly after the treatment using FZJGF. The pathological improvements were observed. FZJGF could markedly alleviate the deposition of collageneous fiber, and reduce the liver pseudoluboli and the fibrosis scores in the liver tissue compared with model group.

CONCLUSION

FZJGF can inhibit formation and development of rat hepatic fibrosis induced by the human serum albumin.

[Analysis on therapeutic effect of substance-partitioned moxibustion at Guanyuan (CV 4) and shenque (CV 8) for treatment of primary dysmenorrhea of cold-damp type]

OBJECTIVE

To observe clinical therapeutic effect of substance-partitioned moxibustion on primary dysmenorrhea (PD). Methods One hundred and thirty-eight cases of PD were randomly divided into two groups, the treatment group (n=78) were treated with substance-partitioned moxibustion at Guanyuan (CV 4) and Shenque (CV 8), once a day; and the control group (n=60) treated with oral administration of Yueyueshu Powder, twice a day, 10 g each time. They were treated for 3 menstrual cycles.

RESULTS

The total effective rate and the index of therapeutic effect were 96.1% and 90.8% in the treatment group, and 88.3% and 76.2% in the control group, respectively, with a significant difference between the two groups (P < 0.05).

CONCLUSION

Clinical therapeutic effect of substance-partitioned moxibustion on primary dysmenorrhea is obvious.

Intracellular TGF-beta receptor blockade abrogates Smad-dependent fibroblast activation in vitro and in vivo

Fibrosis, the hallmark of scleroderma, is characterized by excessive synthesis of collagen and extracellular matrix proteins and accumulation of myofibroblasts. Transforming growth factor-beta (TGF-beta), a potent inducer of collagen synthesis, cytokine production, and myofibroblast transdifferentiation, is implicated in fibrosis. Profibrotic TGF-beta responses are induced primarily via the type I activin-like receptor kinase 5 (ALK5) TGF-beta receptor coupled to Smad signal transducers. Here, we investigated the effect of blocking ALK5 function with SM305, a novel small-molecule kinase inhibitor, on fibrotic TGF-beta responses. In normal dermal fibroblasts, SM305 abrogated the ligand-induced phosphorylation, nuclear import, and DNA-binding activity of Smad2/3 and Smad4, and inhibited Smad2/3-dependent transcriptional responses. Furthermore, SM305 blocked TGF-beta-induced extracellular matrix gene expression, cytokine production, and myofibroblast transdifferentiation. In unstimulated scleroderma fibroblasts, SM305 caused a variable and modest reduction in type I collagen levels, and failed to abrogate constitutive nuclear accumulation of Smad2/3, or alter the proportion of smooth muscle actin stress fiber-positive fibroblasts. In vivo, SM305 prevented TGF-beta-induced Smad2/3 phosphorylation type I collagen (COL1)A2 promoter activation in dermal fibroblasts. Taken together, these results indicate that SM305 inhibits intracellular TGF-beta signaling through selective interference with ALK5-mediated Smad activation, resulting in marked suppression of profibrotic responses induced by TGF-beta in vivo and in vitro.

Relationships between the changes of serum levels of OPG and RANKL with age, menopause, bone biochemical markers and bone mineral density in Chinese women aged 20-75

The correlations between the serum levels of OPG, RANKL with age, menopause, bone markers, and bone mineral densities (BMDs) at the lumbar spine and proximal femur were studied in 504 pre- and postmenopausal Chinese women aged 20-75 years. We found that age was positively and negatively correlated with serum concentrations of OPG (r = 0.442, P < 0.001) and RANKL (r = -0.263, P < 0.001), respectively. Compared with premenopausal women, postmenopausal women showed higher serum OPG levels (107.6 +/- 3.0 vs 72.0 +/- 1.8 pg/ml, P < 0.001), lower serum RANKL concentrations (4.7 +/- 0.4 vs. 5.8 +/- 0.3 pg/ml, P < 0.001) and RANKL/OPG ratios (0.045 +/- 0. 004 vs. 0.099 +/- 0.008, P < 0.001). Neither serum levels of OPG nor RANKL or RANKL/OPG ratio correlated with BMDs after adjustment of age and menopause. They also showed no differences among normal, osteopenic and osteoporotic postmenopausal women. Serum levels of OPG were positively correlated with urinary excretion of NTx (r = 0.1453, P = 0.006). Serum levels of RANKL (r = -0.1928, P < 0.001) and RANKL/OPG ratio (r = -0.1303, P = 0.013) were inversely correlated with serum concentrations of OC. In multiple regression analysis, up to 20% variance (R(2) = 0.106-0.224) of the OPG-RANKL system in peripheral circulation can be explained by age, menopause and bone markers. These results suggest that although serum OPG and RANKL concentrations were unrelated with BMDs, the age- and menopause- dependent changes of serum OPG and RANKL might be a protective mechanism against the accelerated bone loss in postmenopausal women.

Effects of rhM-CSF expressed in silkworm on cytokine productions and membrane molecule expressions of human monocytes

AIM

To study the effects of recombinant human macrophage colony-stimulating factor (rhM-CSF) expressed in silkworm on cytokine productions and membrane molecule expressions of monocytes.

METHODS

The rhM-CSF was added to the human peripheral blood monocyte cultures and 3 d later, the culture supernatants and cells were collected, respectively. TNF-alpha, IL-6, IL-8, and IFN-alpha levels in the supernatants were detected by biological activity test or ELISA and expressions of CD11b, CD16, HLA I, and HLA II on the cellular surface were examined by the method of alkaline phosphatase anti-alkaline phosphatase complex (APAAP).

RESULTS

The rhM-CSF promoted TNF-alpha, IL-6, and IL-8 inductions of monocytes and increased the percentages of CD11b, CD16, HLA I, and HLA II molecule expression on monocytes.

CONCLUSION

The rhM-CSF plays a role in monocyte function up-regulation and has a certain practical value in immunological therapy.

[Effect of oxyphenamone, a new inodilator, on isolated cardiac muscles and arteries]

The cardiotonic and vasodilating effects of oxyphenamone were studied in preparations of rat Langendorff's heart, isolated cardiac muscles of guinea pigs and isolated arteries of dogs. In the preparations of rat Langendorff's heart, infusion of oxyphenamone at 0.1 and 1.0 mumol.L-1 increased myocardial contractility and coronary blood flow moderately and decreased heart rate slightly. Oxyphenamone (1-100 mumol.L-1) increased the contractile force of papillary muscle (PM) and left atrium (LA) of guinea pigs dose-dependently. The positive inotropic effect of oxyphenamone (the ED50 was found to be 18.35 mumol.L-1 in PM and 9.17 mumol.L-1 in LA) was close to that of milrinone, an inhibitor of phosphodiesterase(the ED50 was shown to be 6.23 mumol.L-1 in PM and 4.59 mumol.L-1 in LA). The difference between these two agents is that oxyphenamone decreased the spontaneous pulse rate of right atrium, while milrinone increased it. The vasoconstrictions of dog coronary, basilar and mesenteric arteries induced by KCl, 5-HT and CaCl2 were antagonized non-competitively by oxyphenamone at 1 and 50 mumol.L-1, suggesting that oxyphenamone has a relaxant effect on vascular smooth muscles.

[Effect of oxyphenamone, a new inodilator, on cardiac hemodynamics in normal rat, cat and dog]

For studying the cardiotonic and vasaodilating effect of oxyphenamone in vivo, cardiac hemodynamic variables of anesthetized normal rats, cats and dogs were determined with a polygraph and electromagnetic flowmeters. Intravenous injection of oxyphenamone (0.5-10 mg.kg-1) dose-dependently decreased the mean arterial pressure and systemic vascular resistance moderately and increased cardiac output, myocardial contractile force and +/- dT/dtmax. The blood flow of coronary and femoral arteries increased markedly and their vascular resistance decreased but the blood flow and vascular resistance of cerebral artery did not change. Some species differences were observed in the effect of oxyphenamone on heart rate (HR) and left ventricular pressure (LVP). Oxyphenamone did not influence the HR and LVP in normal cats. It decreased the HR, left ventricular systolic pressure (LVSP) and +/- dP/dtmax, while did not affect the left ventricular end diastolic pressure (LVEDP) in rats. In contrast, administration of oxyphenamone to dogs increased LVSP and +/- dP/dtmax markedly and diminished LVEDP slightly. Oxyphenamone decreased HR slightly at lower dosage (1 and 3 mg.kg-1), but increased heart rate moderately at high dose (6 mg.kg-1) in dogs. These indicate that oxyphenamone has cardiotonic and vasodilating effects in vivo. Whether the effects of oxyphenamone on cardiac hemodynamics would be useful for the treatment of heart failure should be evaluated further.

Detection of the t(2;5)(p23;q35) chromosomal translocation in large B-cell lymphomas other than anaplastic large cell lymphoma

In general, the large cell lymphomas are a cytogenetically heterogeneous group of diseases, and the cytogenetic findings do not correlate with morphological findings in this group of malignant lymphomas. The CD30-positive anaplastic large cell lymphomas, however, are thought to be an exception, with the t(2;5) reported to correlate with the morphological changes of this disease entity. A subgroup of Hodgkin's disease cases have been reported by some investigators to have the t(2;5) translocation, leading to speculation that these two diseases are related. In the current study, the authors used a sensitive reverse transcriptase polymerase chain reaction (RT-PCR) methodology to evaluate the frequency of t(2;5) in 33 cases of large cell lymphoma, of B lineage, other than anaplastic large cell lymphoma. The authors detected evidence of t(2;5) in four of the cases (12%), a frequency similar to that of the authors' previous study of cases of CD30 positive anaplastic large cell lymphoma. Three of the positive large B-cell lymphoma cases were CD30 negative and were morphologically indistinguishable from the cases without evidence of t(2;5). The fourth case had a subpopulation of CD30 positive cells but also did not have morphological features of anaplastic large cell lymphoma. These results would suggest that t(2;5) is not restricted to cases of malignant lymphomas with anaplastic morphology or to CD30 expression.

Absence of the t(2;5) in Hodgkin's disease

The cytogenetics of Hodgkin's disease (HD) is poorly understood. However, a t(2;5) is a common finding in CD30+ anaplastic large cell lymphoma (ALCL), a neoplasm thought by some to be closely related to HD. Recently, the t(2;5) has been cloned and found to represent fusion of the NPM gene with the ALK gene. Using Southern blot hybridization, one group has reported finding rearrangements of NPM in a proportion of cases of both ALCL and HD. In the current study, we used a highly sensitive reverse transcriptase-polymerase chain reaction methodology to analyze 34 cases of HD for the t(2;5). We were unable to find polymerase chain reaction evidence for the t(2;5) in any of the cases of HD, a result significantly different from our previous study of CD30+ non-Hodgkin's lymphomas (P < .02) including ALCL (P < .04), using identical methods. Our results do not support the hypothesis that the t(2;5) represents a common chromosomal abnormality for both HD and ALCL.

Low frequency association of the t(2;5)(p23;q35) chromosomal translocation with CD30+ lymphomas from American and Asian patients. A reverse transcriptase-polymerase chain reaction study

Although cytogenetic data suggest that the t(2;5)-(p23;q35) translocation occurs in many cases of CD30+ lymphomas, the exact frequency of this event is still unknown. To clarify this issue and its epidemiological characteristics, we examined 37 formalin-fixed, paraffin-embedded specimens of CD30+ lymphomas from the United States and Hong Kong by reverse transcriptase-polymerase chain reaction (RT-PCR) for the status of the NPM and ALK genes, which are typically juxtaposed by the t(2;5) translocation. Thirty-four cases were classified as anaplastic large cell lymphomas (ALCL), 2 cases as non-anaplastic large cell lymphomas (LCL), and 1 case as the small cell variant of CD30+ lymphoma. The t(2;5) translocation was detected in 6 cases (16%), including 3 of 18 American patients and 3 of 19 cases from Hong Kong. All cases had a 185-bp NPM RT-PCR product as detected by Southern blot analysis, indicating adequate preservation of mRNA. The 6 positive cases were among 4 of 34 adult lymphomas, as compared with 2 of 3 childhood cases. Five of 17 T-lineage cases were t(2;5)-positive, compared with 1 of 15 B-lineage cases and none of the 5 null-cell or mixed lineage cases. Our results therefore show that t(2;5) occurs at a low frequency among CD30+ lymphomas, at least in our adult-dominated series.

Infrequent association of Epstein-Barr virus with CD30-positive anaplastic large cell lymphomas from American and Asian patients

CD30 (Ki-1)-positive anaplastic large cell lymphoma (CD30+ ALCL) is a morphologically and immunophenotypically distinct subset of non-Hodgkin's lymphoma. Although the presence of Epstein-Barr virus (EBV) has been well documented in a significant proportion of cases of Hodgkin's disease, another CD30+ malignancy, few studies have examined the association of EBV with CD30+ ALCL. These latter studies have produced conflicting findings. To further investigate the existence of a putative association of EBV with CD30+ ALCL, and whether this association, if present, shows geographic variation, we examined 34 formalin-fixed, paraffin-embedded specimens from cases of CD30+ ALCL from the United States and Hong Kong. Immunophenotypically, 15 cases were of B lineage, 15 cases were of T lineage, one case expressed both B- and T-cell markers, and three were of null lineage. A highly sensitive in situ hybridization method was performed with use of an antisense oligonucleotide probe to the EBV-encoded RNA (EBER-1). EBV-RNA was identified in 3 of 14 CD30+ ALCL specimens from Hong Kong patients and in 1 of 20 from the American patients. The EBER-1 signal was present in all or virtually all of the tumor cell nuclei in the three EBV-RNA-positive CD30+ ALCL Hong Kong cases, but was only focally present in the single EBV-positive American case. The latent membrane protein-1 (LMP1) of EBV was identified in only one of the four positive cases, a Hong Kong case. Our results suggest that in contrast to Hodgkin's disease, EBV has no significant association with CD30+ ALCL.

Cellular rejection in discordant xenografts when hyperacute rejection is prevented: analysis using adoptive and passive transfer

Hyperacute rejection of discordant xenografts occurs rapidly, precluding cellular infiltration. Thus the role of cellular rejection in discordant xenografts is debated. Using adoptive transfer of sensitized splenocytes and passive transfer of sensitized serum, we evaluated the influence of cellular and humoral elements on cellular infiltration and rejection in the guinea-pig-to-rat discordant xenograft model. Guinea-pig hearts were transplanted into Lewis rats. Pretransplant, rats underwent splenectomy and plasma exchange and were started on daily cobra venom factor injections. Xenografts rejected faster after adoptive (1, 2, 2 and 2 days) or passive (1, 1, 2 and 2 days) transfer than controls (4, 4, 4 and 4 days; p < 0.05). Macrophages and neutrophils were predominant in early prerejection specimens. Over time, cellular infiltrates were dominated by mononuclear cells. Natural killer cells were present in all groups, as were interleukin 2 receptor positive cells. Our data suggest that either sensitized serum or sensitized cells are capable of initiating an accelerated rejection characterized by cellular infiltration. Despite subtle differences, the population of infiltrating cells was similar in each group. Thus, although rejection may be initiated by either cellular or humoral influences, the ultimate result is the same. We have, therefore, established a small animal model to study cellular rejection in discordant xenografts. This model will help evaluate the role of cell subsets and xenoantibodies in xenograft rejection and will help determine the precise relationship between the two when hyperacute rejection is prevented.

The immunopathology of cardiac xenograft rejection in the guinea pig-to-rat model

The mechanisms underlying rejection by rats of vascularized guinea pig xenografts have been controversial. The aim of this study was to define, using sequential immunopathologic analysis, the contributions of xenoreactive antibody, complement, and effector cells to the rejection of guinea pig cardiac xenografts by Lewis rats. In untreated recipients, hyperacute rejection of guinea pig cardiac xenografts occurred in 20 +/- 10.2 min and was characterized by focal endothelial deposition of IgM and by diffuse deposition of C3. IgG was not localized to endothelial surfaces, but was present in the same locations as albumin, suggesting that the accumulation of IgG might reflect nonspecific leakage of plasma proteins from blood vessels. No polymorphonuclear or monocytic infiltrate was observed. Depletion from rats of xenoreactive antibody to undetectable levels prolonged the survival of guinea pig cardiac xenografts, but did not prevent hyperacute rejection; the rejected xenografts contained deposits of C3 along the microvasculature but no deposits of IgM or IgG. No cellular infiltrate was observed. Depletion of complement with cobra venom factor prolonged the survival of xenografts up to 96 hr. Xenograft tissues from complement-depleted animals had diffuse deposits of IgM along the microvasculature, but no detectable deposits of C3 or IgG were noted. Graft tissues obtained at various times after transplantation into complement-depleted animals revealed cellular infiltrates consisting of granulocytes, monocytes, and lymphocytes, but few cells bearing an NK cell phenotype. Our findings are consistent with the concept that complement activation is essential for the hyperacute rejection of discordant xenografts, and that in this particular model complement activation can proceed without the involvement of antibody. However, our findings also suggest that xenoreactive antibody contributes to hyperacute rejection and, along with effector cells, contributes to the later rejection of a xenograft when hyperacute rejection has been averted. Finally, we show that when hyperacute rejection is avoided, a form of vascular rejection occurs in which certain of the pathologic features--i.e., interstitial hemorrhage, interstitial edema, and thrombosis--are very similar to those observed in hyperacute rejection. Whether this form of rejection is a delayed form of the process that leads to hyperacute rejection or a novel pathologic process of graft rejection has yet to be determined.

Protective effect of puerarin against myocardial reperfusion injury. Myocardial metabolism and ultrastructure

To ascertain the beneficial effect of puerarin on the myocardium against reperfusion injury, studies on myocardial metabolism and ultrastructure were made. Twelve dogs divided into two equal groups were placed on moderate hypothermic cardiopulmonary bypass, and their hearts were subjected to 140 minutes cold cardioplegic arrest and 60 minute reperfusion. In the control group, the hearts were perfused with crystalloid cardioplegic solution (CPS) every 20 minutes during arrest. In the treated group, the hearts received CPS containing puerarin (2 mg/kg). Myocardial oxygen consumption, lactate production, creatine phosphokinase (CPK) release, water content and ultrastructural alterations were determined before ischemia, during cardiac arrest and at reperfusion. The results showed that intermittent infusion of CPS containing puerarin significantly decreased myocardial lactate production during ischemia, as well as myocardial oxygen consumption, CPK release and water content during reperfusion. Under electronmicroscopy, the degree of ischemic damage judged by a scoring method was less pronounced in the puerarin group than in the control. The authors conclude that puerarin has protective effects on the function of hearts that have undergone long periods of arrest and reperfusion.

The protective effect of puerarin against myocardial reperfusion injury. Study on cardiac function

In order to find out if puerarin could protect the hearts from myocardial reperfusion injury after cardiac arrest, twelve dogs divided into two equal groups were placed on moderately hypothermic cardiopulmonary bypass and their hearts were subjected to 140 min of cold cardioplegic arrest and 60 min of reperfusion. In the control group, the hearts were perfused with a crystalloid cardioplegic solution (CPS) through the aortic root every 20 min during arrest. In the treated group, the hearts received CPS containing puerarin (2 mg/kg). Cardiac hemodynamic variables were monitored throughout the experiments. Left ventricular function curves were formed before ischemia and after 60 min of reperfusion. The results showed that the recovery of left ventricular function in the treated group was significantly better than that in the controls (81 +/- 11% versus 39 +/- 7%, P less than 0.01). Compared with preischemic values, the increase of coronary blood flow (CBF) at cardiac arrest in the puerarin-treated group was higher than that in the control group (214 +/- 11 versus 177 +/- 4 ml/min, P less than 0.01). The data indicate that puerarin has protective effects on the cardiac function after prolonged arrest and reperfusion.

Translocations and rearrangements in T-cell acute leukemias with the t(11;14) (p13;q11) chromosomal translocations

Chromosomal translocations involving the T-cell receptor alpha and delta genes at q11 on chromosome 14 are the most common cytogenetic abnormalities in patients with T-cell tumors. We have demonstrated that the t(11;14)(p13;q11) translocation in two T-ALL patients involves the J delta region suggesting that the translocation proceeds or coincides with delta gene rearrangement. Additional rearrangements on both normal and translocated chromosomes 14 are described including rearrangement of both Tcr-alpha and Tcr-delta genes, and deletions within the J alpha region. The polyclonality of rearrangements on the normal chromosome 14 in one of the patient samples demonstrates that T-cell receptor rearrangement continues after the translocation event. The identification of clonally expanded rearrangements involving both the Tcr-delta and the Tcr-alpha genes in a single patient suggests a cascade model for delta----alpha expression may be a viable pathway for T-cell maturation.

Interactions between glucocorticoid receptor-bearing chromatin and antireceptor antibody preparations

Recent evidence indicates that the control of gene expression by steroid hormones is mediated by hormone-receptor complexes bound at specific chromosomal locations. The isolation of these in vivo sites of binding would be useful in an analysis of the mechanism of this control. We have therefore examined the interaction between two different antiglucocorticoid receptor antibody preparations and a defined chromatin fraction containing bound glucocorticoid receptors in order to test the feasibility of this approach. Both antibody preparations, when attached to sepharose, removed nucleosome-bound and nucleosome free receptor from solution, indicating that chromatin-bound receptor was exposed and available for reaction with antibody. The bulk of the chromatin, not containing receptor, was mainly unaffected during these reactions, showing that the antibodies exhibited significant specificity. To determine whether the nucleosome-bound receptor remained attached to the nucleosome during reaction with antibody, studies using soluble antibody were performed. One of the antibodies caused a shift in the sedimentation rate of the nucleosome-bound receptor from 11S to 11.5S, suggesting that an intact ternary complex of antibody-receptor-nucleosome had formed. The other antibody produced various-sized aggregates of the free and bound receptors. Surprisingly, we found that one of the antibodies reacted strongly with free and nucleosome-bound estrogen receptors as well as glucocorticoid receptors. These studies suggest that an antibody preparation with appropriate characteristics should permit isolation of chromosomal receptor binding sites.

The induction of Alu-sequence transcripts by glucocorticoid in rat liver cells

Two cDNA clones isolated from a library prepared from dexamethasone-treated rat hepatoma cells have permitted us to detect the presence and the induction of heterogeneous, mainly short, RNA molecules in hepatoma cells and in rat liver, but not in several other rat tissues. The induction by dexamethasone is inhibited by 100 X progesterone. Pulse label experiments suggest that it occurs in part at least, at the level of transcription and may be mediated by RNA polymerase III. The induction of the RNAs is stimulated by cycloheximide, even in the absence of hormone, but not significantly by other stressful conditions. One line of hepatoma cells spontaneously lost its ability to induce these RNAs and synthesized them constitutively. These altered cells showed proper induction of another dexamethasone-mediated response, indicating that the glucocorticoid receptor was functionally normal in these cells. The two clones contain a type 2 Alu-like sequence. The short RNAs can be distinguished from 7SL RNA, which also contains Alu-sequences. We hypothesize that the synthesis of these RNAs may be regulated by an inhibitor of transcription which is inactivated by dexamethasone. Accordingly, cycloheximide relieves the inhibition by preventing synthesis of the inhibitor and the altered cell line has spontaneously lost the function of the inhibitor. The function of these RNAs for the cell is not known. We believe this to be the first report of hormone-regulated tissue specific synthesis of repeat-sequence transcripts.

Cloning and sequencing of a rearranged V lambda gene from a Burkitt's lymphoma cell line expressing kappa light chains

We have cloned and sequenced a rearranged V lambda gene from a Burkitt's lymphoma cell line PA682(PB). This cell line has two rearranged kappa loci and has been shown to be expressing kappa light chains. This V lambda gene has been identified as a member of the V lambda subgroup III gene family based on the homology of the predicted amino acid sequence of PAV lambda with the reported sequences of the V lambda protein DEL of subgroup III. Nine cross-hybridizing bands have been detected on Southern blots and the chromosomal orientation of the V lambda subgroup III gene family has been determined in relation to the V lambda subgroup I gene family. Although the PAV lambda rearrangement has occurred via a legitimate V-J joining and a normal size transcript is detected on Northern blots, the nucleotide sequence reveals a high level of mutations resulting in multiple termination signals within the V gene coding sequence and only a truncated V lambda protein can be translated. This confirms previous observations that although multiple light chain genes may be transcribed, only one functional light chain protein can be synthesized.

Identification of glucocorticoid-induced genes in rat hepatoma cells by isolation of cloned cDNA sequences

The expression of specific cellular genes in M1.19 rat hepatoma cells involves glucocorticoid regulation by mechanisms that are not well understood. To approach this problem we cloned cDNA prepared from dexamethasone-induced poly(A)-RNA and used a comparative colony hybridization method to identify recombinant clones containing hormone-regulated sequences. Two such cDNA clones, p1394 and p255, hybridize to a homogeneous RNA species of 900 nucleotides that is present in high abundance in 24-hr-induced cells but is undetectable in uninduced cells. This RNA can be seen as early as 1 hr after dexamethasone stimulation. Inhibition of protein synthesis with cycloheximide significantly reduces the accumulation of the RNA but does not abolish the induction response. In normal adult rat liver the RNA is abundant, and this RNA is induced by dexamethasone in adrenalectomized rats. Plasmids p1394 and p255 contain sequences that are homologous to the mRNA coding for the acute-phase reactant protein alpha 1-acid glycoprotein. Two other cDNA clones, p655 and p333, hybridize to a more heterogeneous RNA species 200-400 nucleotides in size with a lower induction response to dexamethasone. Southern blot analysis of M1.19 genomic DNA indicates that p1394 and p255 are complementary to a single DNA fragment, whereas p655 and p333 are complementary to repetitive sequences in the M1.19 genome. It appears that the genetic domain of glucocorticoid control in M1.19 rat hepatoma cells involves low copy number genes such as alpha 1-acid glycoprotein as well as repetitive sequence elements.

Progesterone, glucocorticoid and estradiol receptors in MCF-7 cells bind to chromatin

MCF-7 cells contain progesterone, estradiol and glucocorticoid receptors. Following addition of these hormones to the growth medium of the cells, hormone-receptor complexes were found to sediment with chromatin fragments produced by trace digestion with micrococcal nuclease. The binding in all cases could be competed by excess unlabeled hormone. In each case the fragments with which the hormone-receptor complexes were associated tended to be smaller than the bulk chromatin fragments, indicating a greater sensitivity of those chromatin regions to the nuclease. The mononucleosomes released by more extensive digestion with micrococcal nuclease contained different amounts of each of the three hormone-receptor complexes. Progesterone could usually be detected on mononucleosomes only after very brief sedimentation analyses, whereas glucocorticoid- and estradiol-labeled mononucleosomes were stable during long centrifugations. Comparison of glucocorticoid- and estradiol-labeled mononucleosomes indicated that their sedimentation rates differed from one another and from bulk nucleosomes. Estradiol nucleosomes from MCF-7 cells and rat uterus (Senior and Frankel, 1978) sediment significantly faster than bulk nucleosomes, while glucocorticoid nucleosomes from MCF-7 cells and rat hepatoma cells sediment with, or even fractionally slower than, bulk nucleosomes.

Adaptive Changes in ATPase Activity in the Cells of Winter Wheat Seedlings during Cold Hardening

A cytochemical study of ATPase activity in the cells of cold hardened and nonhardened winter wheat (Triticum aestivum L. cv. Nongke No. 1) seedlings was carried out by electron microscopic observation of lead phosphate precipitation. ATPase activity associated with various cellular organelles was altered during cold hardening. (a) At 22 degrees C, high plasmalemma ATPase activity was observed in both cold hardened and nonhardened tissues; at 5 degrees C, high activity of plasmalemma ATPase was observed in hardened tissues, but not in unhardened tissues. (b) In nonhardened tissues, tonoplast and vacuoles did not exhibit high ATPase activity at either 22 or 5 degrees C, while in hardened tissues high activity was observed at both temperatures. (c) At 5 degrees C, ATPase activity of nucleoli and chromatin was decreased in hardened tissues, but not in nonhardened tissues. It is suggested that adaptive changes in ATPase activity associated with a particular cellular organelle or membrane may be associated with the development of frost resistance of winter wheat seedlings.