Detection of SARS-CoV-2 Neutralizing Antibodies in Vaccinated Pregnant Women and Neonates by Using a Lateral Flow Immunoassay Coupled with a Spectrum-Based Reader

The focus of this study was to investigate the detection of neutralizing antibodies (Nabs) in maternal serum and cord blood as the targeted samples by employing a lateral flow immunoassay combined with a spectrum reader (LFI-SR) and the correlation of Nab protection against different types of SARS-CoV-2. We enrolled 20 pregnant women who were vaccinated with the Moderna (mRNA-1273) vaccine during pregnancy and collected 40 samples during delivery. We used an LFI-SR for the level of spike protein receptor binding domain antibody (SRBD IgG) as Nabs and examined the correlation of the SRBD IgG concentration and Nab inhibition rates (NabIR) via enzyme-linked immunosorbent assays (ELISA). The LFI-SR had high confidence for the SRBD IgG level (p < 0.0001). Better NabIR were found in wild-type SARS-CoV-2 (WT) compared to Delta-type (DT) and Omicron-type (OT). Women with two-dose vaccinations demonstrated greater NabIR than those with a single dose. The cut-off value of the SRBD IgG level by the LFI-SR for NabIR to DT (≥30%; ≥70%) was 60.15 and 150.21 ng/mL for mothers (both p = 0.005), and 156.31 (p = 0.011) and 230.20 ng/mL (p = 0.006) for babies, respectively. An additional vaccine booster may be considered for those mothers with SRBD IgG levels < 60.15 ng/mL, and close protection should be given for those neonates with SRBD IgG levels < 150.21 ng/mL, since there is no available vaccine for them.

Sulforaphane Induces Cell Death Through G2/M Phase Arrest and Triggers Apoptosis in HCT 116 Human Colon Cancer Cells

Sulforaphane (SFN), an isothiocyanate, exists exclusively in cruciferous vegetables, and has been shown to possess potent antitumor and chemopreventive activity. However, there is no available information that shows SFN affecting human colon cancer HCT 116 cells. In the present study, we found that SFN induced cell morphological changes, which were photographed by contrast-phase microscopy, and decreased viability. SFN also induced G2/M phase arrest and cell apoptosis in HCT 116 cells, which were measured with flow cytometric assays. Western blotting indicated that SFN increased Cyclin A, cdk 2, Cyclin B and WEE1, but decreased Cdc 25C, cdk1 protein expressions that led to G2/M phase arrest. Apoptotic cell death was also confirmed by Annexin V/PI and DAPI staining and DNA gel electrophoresis in HCT 116 cells after exposure to SFN. The flow cytometric assay also showed that SFN induced the generation of reactive oxygen species (ROS) and Ca[Formula: see text] and decreased mitochondria membrane potential and increased caspase-8, -9 and -3 activities in HCT 116 cell. Western blotting also showed that SFN induced the release of cytochrome c, and AIF, which was confirmed by confocal microscopy examination. SFN induced ER stress-associated protein expression. Based on those observations, we suggest that SFN may be used as a novel anticancer agent for the treatment of human colon cancer in the future.

Cantharidin induces DNA damage and inhibits DNA repair-associated protein expressions in TSGH8301 human bladder cancer cell

Cantharidin is an active component of mylabris, which has been used as a traditional Chinese medicine. Cantharidin has been shown to have antitumor activity against several types of human cancers in vitro and in animal models in vivo. We investigated whether cantharidin induces DNA damage and affects DNA damage repair-associated protein levels in TSGH8301 human bladder cancer cells. Using flow cytometry to measure viable cells, cantharidin was found to reduce the number of viable cells in a dose-dependent manner. Comet assay, 4',6-diamidino-2-phenylindole (DAPI) staining and DNA gel electrophoresis were used to measure DNA damage and condensation; the results indicated that cantharidin induced DNA damage (comet tail), DNA condensation (white DAPI staining) and DNA damage (DNA smear). Results from western blotting showed that cantharidin inhibited the expression of DNA-dependent serine/threonine protein kinase, poly-ADP ribose polymerase, phosphate-ataxia-telangiectasia and RAD3-related, O-6-methylguanine-DNA methyltransferase, breast cancer susceptibility protein 1, mediator of DNA damage checkpoint protein 1, phospho-histone H2A.X, but increased that of phosphorylated p53 following 6 and 24 h treatment. Confocal laser microscopy was used to examine the protein translocation; cantharidin suppressed the levels of p-H2A.X and MDC1 but increased the levels of p-p53 in TSGH8301 cells. In conclusion, we found that cantharidin-induced cell death may occur through the induction of DNA damage and suppression of DNA repair-associated protein expression in TSGH8301 cells.

Atlantal stenosis: a rare cause of quadriparesis in a child. Case report

The authors report the case of a 3-year-old boy who suffered from quadriparesis and respiratory distress after failing to execute a somersault properly. Neuroimaging revealed spinal cord contusion with marked spinal canal stenosis at the level of the atlas. No subtle instability, occult fracture, or other congenital abnormalities were confirmed. Spinal cord contusion with marked canal stenosis is rare, and only several adult cases have been reported. Severe stenosis at the level of the atlas may predispose individuals to severe spinal cord contusion, as occurred in our patient after sustaining trivial trauma.

Mediastinal lipoblastoma with intraspinal extension: MRI demonstration

Lipoblastomatous lesions are mesenchymal tumors of embryonal white fat and are classified into two forms: a superficial, well-defined mass (lipoblastoma) or a deep, infiltrative lesion (lipoblastomatosis). We report an unique case of mediastinal lipoblastoma in a 17-month-old boy which harbored a dual nature and exhibited the characteristics of both forms, a large well-encapsulated intrathoracic main tumor with focal infiltrative features at the thoracic inlet and transforaminal intraspinal extension forming a long-segment extradural mass. In addition to specific signal characterization of a fatty mediastinal mass with intratumoral streaks and whorls corresponding to the fibrovascular network, magnetic resonance (MR) imaging offered clear demonstration of the chest wall, lower neck and intraspinal extension, which was important for preoperative planning.

Fibrosis of the omohyoid muscle--an unusual cause of torticollis

An 11-year-old boy had a left neck mass with torticollis. On exploration, a fibrotic mass in the superior belly of the left omohyoid muscle was found, which shortened the muscle and pulled the hyoid bone downward. Resection of the fibrotic muscle was performed. The patient recovered well after the operation with resolution of his torticollis.

Transthoracic endoscopic sympathectomy for primary palmar hyperhidrosis in children

Primary palmar hyperhidrosis often starts in childhood. It usually causes academic and social disabling at the age children begin primary school. This study included 65 children (44 girls and 21 boys, mean age 13.5 years) who underwent one-stage bilateral transthoracic endoscopic sympathectomy. The proper sympathetic segment was visualized in almost all cases and electrocautery ablation was performed. The immediate postoperative course was uneventful in all cases and no major morbidity was encountered. Horner's syndrome did not occur in any case. All patients were discharged the day of surgery or after an overnight stay. The duration of follow-up was from 6 months to 3 years. Although compensatory sweating was found in 40% of the patients, long-term satisfaction was reported in 63 cases (96%). This procedure is effective, simple, and is recommended as the method of choice for surgical treatment of severe upper extremity hyperhidrosis in children.

Juvenile fibromatosis of the posterior mediastinum with intraspinal extension

Chest radiography, CT, and MR imaging were performed in a 3-year-old girl who had posterior mediastinal fibromatosis with transforaminal intraspinal and chest wall extension. Chest radiographs and CT scans showed a slow-growing, noncalcified but locally aggressive left paravertebral mass. The mass was slightly hyperintense relative to muscle on both T1-weighted and fast spin-echo T2-weighted MR images.

Posterior cerebral artery aneurysm in a two-year-old girl

Intracranial aneurysms are seldom encountered in the pediatric age group, and those within the posterior circulation are even more rare. Intracranial aneurysms in children differ from adult aneurysms in size, distribution, histology and incidence of symptoms. The authors report a 2-year-old female patient with a posterior cerebral artery aneurysm presenting with seizures, right third nerve palsy and right hemiparesis caused by compression of the contralateral cerebral peduncle. The patient underwent a pterional craniotomy and clipping of the aneurysm. Right oculomotor nerve palsy remained postoperatively. We review the literature and discuss the characteristics of aneurysms of the posterior cerebral artery and those in early childhood.

Lupus in Chinese male: a retrospective study of 61 patients

BACKGROUND

Systemic lupus erythematosus (SLE) has traditionally been considered a disease of women, and is uncommon in men. In recent years, several large clinical series of male lupus patients have been reported. As no known data are available for lupus in males from Taiwan, a retrospective analysis of data from male lupus patients was done to determine whether these patients differed from other series of male or female SLE patients in the literature.

METHODS

Sixty-one male lupus patients, diagnosed and followed in Tri-Service General Hospital, between 1983 and 1993, were studied and their data analyzed, retrospectively.

RESULTS

The mean age of diagnosis was 30 +/- 17 (mean +/- SD, range: 13-81) years. The peak age of diagnosis was between 13 and 40 years. The mean duration of follow-up was 36 +/- 36 (range: 2-256) months. The 1-, 5- and 10-year survival rates were 84%, 76% and 75%, respectively. The frequency of clinical manifestations were renal disease, 75%; malar rash, 70%; arthritis, 60%; fever, 56%; photosensitivity, 48%; pleuritis, 39%; pericarditis, 31%; alopecia, 31%; mucosal ulcers, 29%; neuropsychiatric disease, 26%; discoid lupus, 21%; vasculitis, 15%; Raynaud's phenomenon, 10%; and lymphadenopathy, 2%. The frequency of abnormal laboratory findings were antinuclear antibodies (ANA), 95%; hypocomplementemia, 77%; antibodies to double-stranded DNA (anti-dsDNA), 57%; leukopenia, 44%; lupus erythematosus (LE) cells, 39%; anti-Ro, 39%; anti-Smith antibodies (anti-Sm), 19%; thrombocytopenia, 18%; rheumatoid factor, 17%; anti-ribonucleoprotein antibody (anti-RNP), 14%; autoimmune hemolytic anemia, 8%; false-positive venereal disease research laboratory test (VDRL), 6% and anti-La, 4%.

CONCLUSIONS

In a review of the 61 ethnic Chinese male lupus patients, a higher frequency of renal disease, malar rash and photosensitivity, but a lower frequency of arthritis and lymphadenopathy, compared to previous reports of Caucasians. There were no significant immunological differences from other series of male lupus, except a lower frequency of anti-dsDNA. In general, poor prognosis was noted for male lupus patients here.

Acquired immunodeficiency syndrome with CNS toxoplasmosis: a case report

Central nervous system (CNS) toxoplasmosis is an important infectious complication of acquired immunodeficiency syndrome (AIDS) which appears to result from reactivation of a previously acquired infection and requires prolonged treatment. A 31-year-old male presented in a drowsy mental state and with an unstable gait. Computerized tomographic (CT) scan and magnetic resonance imaging (MRI) showed multiple nodular lesions in the cerebrum and cerebellum; the seropositivity for the human immunodeficiency virus (HIV-1) and high serum IgG toxoplasma titers were also demonstrated. A presumptive diagnosis of CNS toxoplasmosis was based on neurological signs and neuroradiological findings. This was confirmed by improvement in both clinical and neuroradiological pictures during treatment with pyrimethamine and clindamycin. Four months later, however the patient died of intracranial hemorrhage and massive upper GI bleeding.

Coexisting IgA nephropathy and leukocytoclastic cutaneous vasculitis associated with ankylosing spondylitis: a case report

A patient with ankylosing spondylitis and coexisting IgA nephropathy and leukocytoclastic cutaneous vasculitis is described. Renal biopsy demonstrated mesangial proliferative glomerulonephritis with prominent IgA, C3 and fibrin deposition in the glomeruli. Simultaneously, leukocytoclastic cutaneous vasculitis with prominent IgG, IgA and C3 deposition of dermal vessel wall was also observed in the skin biopsy specimen. Such associations have been previously reported in only four cases. This report once again indicates that antigenic mucosal stimulation may play an important role in the pathogenesis of ankylosing spondylitis.

Effects of nebulized terbutaline on oxygen saturation in acute asthmatic children

To evaluate the paradoxical effect of oxygen desaturation following beta-2 bronchodilator nebulization treatment in acute asthmatic children, a total of 47 patients, aged between 1.8 and 14 years, 27 males and 20 females, were studied. Twenty ml of nebulized normal saline (NS), followed by 10 mg (4 ml) of terbutaline sulphate solution (TSS) in 20 ml NS, were delivered by an ultrasonic nebulizer in 10 min to each patient through a connecting air tube placed in front of the nose and mouth. Oxygen saturation (SaO2) and pulse rate were monitored, using a pulse oximeter, before study and every two minutes until the end of the study. The clinical severity score and peak expiratory flow rate (PEFR) were checked before the study, at the end of inhalation of NS, and at the end of inhalation of TSS. SaO2 was increased both after nebulized NS and TSS when compared with the pre-study data (p < 0.05 and p < 0.0001, respectively). Twenty two cases (47%) during NS and 12 cases (25%) during TSS nebulization had SaO2 below the pre-study level. The mean decrease of SaO2 for the former was 1.62 +/- 0.95% (range: 1.00% to 4.26%), and 1.64 +/- 0.83% (range: 1.02% to 3.13%) for the latter (p > 0.9). No SaO2 decrease after nebulized TSS was observed in any of the seven severe asthmatic children with a prestudy SaO2 < or = 90%. The clinical severity score and PEFR were also significantly improved both after nebulized NS and TSS (p < 0.0001 and p < 0.001, respectively for NS, and both p < 0.0001 for TSS).(ABSTRACT TRUNCATED AT 250 WORDS)

A case of demyelinating disease with clinical and radiological features mimicking cerebral tumor

Demyelinating disease may present with clinical and radiological features mimicking brain tumor. A 43-year-old man was admitted because of progressive right hemiparesis, facial weakness and dysarthria. Computed tomographic scans revealed two expansive lesions in the left frontal lobe and midbrain, respectively. A brain tumor or metastatic lesion was suspected. The patient underwent left frontal craniotomy and the surgical biopsy revealed a demyelinating process. The patient, however, had a poor response to steroid treatment and died two months later. The possible nature of demyelinating disease in this case is discussed.

Magnetic resonance imaging of radiation necrosis after radiotherapy for acromegaly: report of a case

A total 5,600 cGy in 28 fractions in 44 days was delivered to a 53-year-old woman with acromegaly after transsphenoid removal of a pituitary adenoma. Sixteen months later, she suffered a progressive loss of vision. Radiation optic neuropathy was diagnosed. A T1-weighted imaging showed gadolinium-enhanced lesions in the optic chiasm, pituitary stalk and hypothalamus. Magnetic resonance imaging is uniquely suited to detect radiation injury to the sellar region. The complications of radiation therapy for benign tumor can be severe even by current standard procedures.

Biological activity of a K-ras mutant that contains the 12R/59T/116Y mutations

The 12R/59T/116Y mutations have been shown to confer a dominant negative activity on H-ras oncogene (H-ras 116Y). To determine whether this event is unique for H-ras, we introduced the same mutations into K-ras oncogene. This mutant, K-ras 116Y, suppressed transformed phenotypes induced by overexpression of H-ras proto-oncogene. NIH3T3 cells expressing K-ras 116Y were resistant to transformation by v-fes oncogene. Analysis of chimaeras between H- and K-ras 116Y showed that the C-terminal variable region determines the level of suppressor activity. These results suggest that these mutations are applicable to other GDP/GTP binding proteins.

Resistance of NIH3T3 cells to v-fes transformation induced by a dominant negative H-ras mutant

NIH3T3 cells carrying a dominant negative H-ras mutant 116Y acquired resistance to transformation by some PTK oncogenes, i.e., v-fes, v-abl, and v-fms, but were sensitive to viral ras and serine threonine kinase oncogenes, v-raf and v-mos. One clone, designated 1-20, infected with v-fes (1-20 fes) exhibited flat morphology and anchorage-dependent cell growth, as did noninfected 1-20 cells. The 1-20 fes cells expressed v-fes oncogene and produced transforming viruses, although these levels were much lower than those in NIH3T3 cells infected with v-fes (NIH3T3 fes). v-fes mRNAs in NIH3T3 fes cells rapidly increased after infection, while accumulation of the v-fes transcripts in 1-20 fes cells was significantly prolonged. Total tyrosine phosphorylation in both NIH3T3 fes and 1-20 fes cells was correlated with the amounts of pp110v-fes. A few proteins were phosphorylated only in NIH3T3 fes but not in 1-20 fes cells. These results suggest that the cellular ras is involved in a signaling pathway from pp110v-fes and this signal stimulates v-fes expression. Inhibition of the ras function may down-regulate this pathway and result in resistance to transformation by v-fes.

[Fetus in fetu: report of a single case]

A five-year-old girl had been noted, since birth to have abdominal distension. There was no history of twinning or teratoma in the family. Physical examination discovered a 15 x 10 cm mass in the abdomen. Roentgenologic examination demonstrated the presence of an axial skeleton and long bones within the mass. MRI showed a retroperitoneal mass with components of cystic, bony and fatty tissues. When the mass was surgically removed from the retroperitoneal cavity, pathologic examination disclosed a parasitic fetus measuring 15.3 x 6.3 x 6.0 cm in size and suspended by a peduncle within a capsule. The fetus was covered with skin, sebaceous materials and black hair. There were bilateral and symmetric upper extremities with a flapper-like, deformed hand. No obvious genital organ was noted. Dissection of the midline, revealed a vertebral column with spinal cord. An atrophic skull bone containing cephalized glial tissue was noted. A thoracic cavity and scapular bone were found in the thoracic cage; however, no heart was noted. Gastrointestinal tract and kidney-like organs were seen within the abdominal cavity. Microscopically, there were glial tissues within the skull bone, spinal cord and vertebra. The upper extremities revealed two long bones surrounded by myxomatous and fibrous tissue. A well developed intestine and an ovary containing follicles with nearby lympy nodes were seen. The capsule showed fibrous tissue with calcification and hairs. It was distinguished from the teratoma by the presence of a vertebral axis and by an appropriate arrangement of other organs or limbs with respect to the axis, and corresponding to the generally recognized diagnostic criteria of fetus in fetu.

Induction and progression of the transformed phenotype in cloned rat embryo fibroblast cells: studies employing type 5 adenovirus and wild-type and mutant Ha-ras oncogenes

Transformation of cloned rat embryo fibroblast (CREF) cells with the wild-type 5 adenovirus (wtAd5) transforming genes E1A and E1B (which extend from 0 to 11.2 map units) results in morphologically transformed cells that exhibit an increased saturation density in monolayer culture and display an anchorage-independent phenotype. WtAd5-transformed CREF (wtAd5 CREF) cells do not, however, induce tumors when injected subcutaneously into athymic nude mice or syngeneic Fischer rats. We have analyzed the effect of the ras oncogene and site-specific mutants in the ras oncogene that result in p21 proteins with altered biochemical properties on the oncogenic and metastatic properties of singly (ras) and doubly (ras + wtAd5) transformed CREF cells. Transformants expressing the wild-type ras p21 protein and ras mutants producing p21 proteins that retained GTP-binding properties grew in agar, induced tumors in nude mice and syngeneic rats, and metastasized to the lungs of rats when injected into their tail veins. In contrast, cells transformed with the ras mutant 116K (which contains a mutation at residue 116 that produces a Lys instead of an Asn and does not bind GTP or induce CREF cells to grow in agar) did not become morphologically transformed and were not oncogenic when injected subcutaneously into either nude mice or Fischer rats; further, such cells were not metastatic when injected into the tail veins of Fischer rats. When the wild-type ras or the ras mutants, including 116K, were expressed in nontumorigenic E1A-plus-E1B-expressing wtAd5 CREF cells, transformed cells induced tumors in both types of animals. The CREF cells doubly transformed with 116K + wtAd5, unlike transformants containing the wild-type ras and the other ras mutants that still retained GTP binding, were still unable to induce lung metastases. In addition, 116K + wtAd5-transformed CREF cells also did not display any alterations in morphology distinguishable from wtAd5 CREF cells and were not able to grow in agar with increased efficiency. These results indicate that the loss of GTP-binding ability by this mutant p21 ras protein eliminated the ability of these proteins to induce an oncogenic phenotype in an immortal but normal CREF cell line. However, the mutant ras could cooperate with wtAd5 transforming genes in transformed CREF cells to make these cells progress to an oncogenic (but not metastatic) phenotype.

[Amniotic band disruption complex: report of one case in twins]

Amniotic band disruption complex is a congenital disorder with the principal features vary from simple digital band constrictions to major craniofacial and visceral defects. Early amniotic rupture results in multiply affected infants who are frequently aborted or stillborn, whereas later rupture results primarily in limb involvement. Here we report a case of amniotic band disruption complex, a male infant (twin A) weighing 2350 gm with Apgar scores of 9 and 10 at one and five minutes. The second, third and fourth fingers on the left hand appeared to have ring constrictions, the distal part of the fourth finger had been amputated distally. There were amputations and ring constrictions of the distal parts of the second, third and fifth digits on the right hand, the fourth finger had only proximal third. All of the toes on the left foot had been amputated distally. The fifth toe on the right foot were absent, and the others had been partly amputated. Left cleft lip and palate were present with sunken left nasal flare. This baby underwent the cranial ultrasound examination, which demonstrated on structural anomalies, and both of the twins had the karyotype of 46XY. No other abnormalities was noted in the infant. The 890 gm placenta was delivered spontaneously. Two umbilical cords were present, each with normal vessels. The examination of the placenta revealed it to be dichorionic and diamniotic, and numerous fibrous strings extending form the fetal surface.

Tumorigenicity, metastasis and suppression of MHC class-I expression in murine fibroblasts transformed by mutant v-ras deficient in GTP binding

We have introduced point mutations in v-rasH to study their effects on biochemical and biological properties of the ras-encoded protein p21. Several of these mutant proteins do not bind GTP and thus lack GTPase activity, while others were shown to have their GTP binding reduced. We have introduced these ras mutants into NIH 3T3 fibroblastoid cells to study major parameters of clinical importance which are associated with neoplastic transformation, particularly MHC expression in cells, metastasis and tumorigenesis in both nude mice and immune competent mice. Our data show that certain mutations in v-ras differentially affect the expression of the transformed phenotype. Mutant ras molecules deficient in GTP binding fail to generate rapidly progressing tumors in immune competent mice, and not all morphologically transformed cells were capable of experimental metastasis. Cells transformed by certain v-ras mutants form tumors in immunocompetent mice and show reduced expression of MHC class-I antigens. Other cells are morphologically transformed and tumorigenic in athymic nude mice, but fail to form tumors in normal mice and show levels of MHC class-I antigen expression similar to non-transformed 3T3 cells. The inverse relationship between MHC class-I-antigen expression and the degree of transformation in fibroblastoid cells suggests that the ras gene product could be involved in regulating MHC expression.

Role of the Ha-ras (RasH) oncogene in mediating progression of the tumor cell phenotype (review)

Recent experimental evidence indicates that the c-Ha-ras (rasH) oncogene may be causally involved in the etiology and evolution of specific human neoplasms. In addition, cultured cells transformed by the rasH oncogene can induce both a tumorigenic and a metastatic phenotype when expressed in appropriate cultured cells. To begin to define the molecular and biochemical mechanism(s) by which the rasH oncogene induce their effects on expression of the transformed state we have employed a cloned rat embryo fibroblast (CREF) cell line. Transformation of CREF cells with wild-type 5 adenovirus (Wt) results in transformed cells which display anchorage-independence and an increased saturation density in monolayer culture, but are non-tumorigenic in both athymic nude mice and syngeneic Fischer rats. In contrast, when CREF cells are transformed with mutant type 5 adenoviruses, such as H5hrl, or the ElA transforming gene from hrl (0-4.5), tumors are induced in both nude mice and syngeneic rats. However, hrl (0-4.5)-transformed CREF cells are not metastatic following intravenous injection into the tail vein of syngeneic rats. Insertion of an activated T24 rasH oncogene or a wild-type v-rasH oncogene into CREF, wt-transformed CREF or hrl (0-4.5)-transformed CREF cells results in acquisition of a metastatic phenotype by these cells. A mutant v-rasH oncogene (mutant 116K), which is defective in GTP binding and the induction of transformation of NIH 3T3 cells, does not induce transformation in CREF cells, but it can progress wt-transformed CREF cells to a tumorigenic-non-metastatic state. Employing this model system which displays well-defined and stable stages in the tumor cell progression lineage, we have analyzed the potential role of changes in the phosphatidylinositol (PI) cycle and phospholipase A2 (PLA2) enzyme activity during progression to a tumorigenic and metastatic phenotype. An increase in PI cycle intermediates (primarily inositol triphosphate; IP3) were observed only in the wt-transformed and hrl (0-4.5)-transformed CREF cell lines transfected with the rasH oncogene. In the case of PLA2, all rasH-transformed CREF cell lines displayed increased activity. In contrast, CREF cells transformed only by Ad5 (Wt or hrl (0-4.5)) or the 116K v-rasH oncogene did not display increased PLA2 activity similar to that observed in rasH transfected cells. Since one important metabolite generated by PLA2 is arachidonic acid, which is converted into prostaglandins and leukotrienes by cyclooxygenase or lipooxygenase, respectively, the levels of prostaglandin E2 (PGE2) in the various cell lines were monitored.(ABSTRACT TRUNCATED AT 400 WORDS)

Interaction of ras oncogene product p21 with guanine nucleotides

The nucleotide exchange reaction was observed with purified ras oncogene product p21 overproduced in Escherichia coli (Hattori, S. et al. (1985) Mol. Cell Biol. 5, 1449-1455) under various conditions. (NH4)2SO4 increased the rate of dissociation of bound GDP from c-rasH and v-rasH p21. The dissociation kinetics were those of a first order reaction, and there was a linear relationship between the rate constant and the (NH4)2SO4 concentration. At any concentration of (NH4)2SO4, the exchange rate was faster with v-rasH p21 than that with c-rasH p21. EDTA and (NH4)2SO4 synergetically stimulated the dissociation reaction. Nucleotide-free p21 was prepared by gel filtration on Sephadex G-25 in the presence of 5 mM EDTA and 200 mM (NH4)2SO4 at room temperature. The free p21 was quite thermolabile, but the addition of GDP or GTP completely protected p21 from thermal inactivation. The dissociation constants for GDP and GTP were determined with free p21 to be 8.9 and 8.2 nM, respectively, for v-rasH p21, and 1.0 and 2.6 nM for c-rasH p21. In the presence of 200 mM (NH4)2SO4, these dissociation constants increased 3- to 12-fold.

Structural significance of the GTP-binding domain of ras p21 studied by site-directed mutagenesis

Point mutations of p21 proteins were constructed by oligonucleotide-directed mutagenesis of the v-rasH oncogene, which substituted amino acid residues within the nucleotide-binding consensus sequence, GXG GXGK. When the glycine residue at position 10, 13, or 15 was substituted with valine, the viral rasH product p21 lost its GTP-binding and autokinase activities. Other substitutions at position 33, 51, or 59 did not impair its binding activity. G418-resistant NIH 3T3 cell lines were derived by transfection with constructs obtained by inserting the mutant proviral DNA into the pSV2neo plasmid. Clones with a valine mutation at position 13 or 15 were incapable of transforming cells, while all other mutants with GTP-binding activity were competent. A mutant with a substitution of valine for glycine at position 10 which had lost its ability to bind GTP and its autokinase activity was fully capable of transforming NIH 3T3 cells. These cells grew in soft agar and rapidly formed tumors in nude mice. The p21 of cell lines derived from tumor explants still lacked the autokinase activity. These findings suggest that the glycine-rich consensus sequence is important in controlling p21 activities and that certain mutations may confer to p21 its active conformation without participation of ligand binding.

Neutralizing monoclonal antibody against ras oncogene product p21 which impairs guanine nucleotide exchange

The neutralizing monoclonal antibody Y13-259 severely hampers the nucleotide exchange reaction between p21-bound and exogenous guanine nucleotides but does not interfere with the association of GDP to p21. These results suggest that the nucleotide exchange reaction is critical for p21 function. Interestingly, the v-ras p21 has a much faster dissociation rate than the p21 of the c-ras proto-oncogene.

Reactivity of a sulfhydryl group of the ras oncogene product p21 modulated by GTP binding

We have studied the sensitivity of sulfhydryl groups of a highly purified p21 protein of the v-rasH oncogene to a thiol-specific reagent, N-ethylmaleimide (NEM). Approximately 70% of GTP binding and autokinase activities of p21 were inactivated by NEM, and excessive amounts of GTP or GDP protected p21 activities. Thiol titration revealed the presence of one fast reactive cysteine residue, the susceptibility of which is modulated by GTP binding. A total of 4 and 6 residues, respectively, became titratable upon denaturation and reduction, suggesting the presence of a disulfide bond. This GTP-modulated sulfhydryl group was identified as Cys-80 in the following tryptic peptide sequence: NH2-Thr-Gly-Glu-Gly-Phe-Leu-Cys-Val-Phe-Ala-Ile-Asn-Asn-Thr-Lys-COOH. This is based on the comparative tryptic peptide mapping of [14C]NEM-modified p21 in the presence and absence of GTP. The GTP-modulated peptide co-chromatographed with a synthetic peptide of the predicted sequence. Amino acid analysis of the purified [14C]NEM-modified peptide from tryptic digests of p21 also confirmed its identity. This region of p21 shares an extensive sequence homology with various G-proteins and appears to be in the vicinity of the GTP-binding domain of these proteins.

Mutations of the ras gene product p21 that abolish guanine nucleotide binding

We have constructed several point mutations affecting the GTP-binding site of p21, the ras-encoded protein. Both lysine (116K) and tyrosine (116Y) mutations of asparagine-116, which, by analogy with the crystal structure of elongation factor Tu (EF-Tu), has critical interactions with the guanine base, abolish GTP binding and transforming activities of p21. These activities are retained by proteins with a mutation at position 117 or 118. Both 116K and 116Y mutant p21s, when overproduced in Escherichia coli, are apparently devoid of GTP-binding and autokinase activities. Similarly, the mutant DNAs do not transform NIH 3T3 cells in a focus-forming assay. By cotransfection with pSV-neo, cell clones resistant to the neomycin analog G418 have been isolated. Cells transfected with 116K or 116Y mutant DNA are contact inhibited. In contrast to competent clones, the defective mutants have no detectable phosphorylated p21. The present results suggest that the basic structure of the GTP-binding site is conserved between p21 and EF-Tu and that this binding site is crucial for ras gene function.

Detection of the intracellular ras p21 oncogene product by flow cytometry

Rapid identification of the expression of oncogene products in specific cell types could potentially be useful in the diagnosis and treatment of human malignancy. We have now observed that through the use of lysolecithin permeabilization and fluorescence-activated flow cytometry, cells expressing high levels of the v-Ha-ras oncogene product, p21, can readily be distinguished from the nontransformed parent cells in a rapid and quantitative manner.

Immunocytochemical localization of RasHa p21 in normal and neoplastic cells in fixed tissue sections from Harvey sarcoma virus-infected mice

An affinity purified sheep IgG antibody to a 20 amino acid peptide from the carboxyterminal end of RasHa p21 was used to localize RasHa p21 on fixed tissue sections of Harvey sarcoma (HaSV) virus-infected mice by the avidin-biotin-peroxidase immunocytochemical technique. Control sera included immune sheep sera absorbed with the peptide, preimmune sheep sera and a goat polyclonal antibody to Rauscher leukemia virus p30. Neonatal BALB/c mice were injected with HaSV/Moloney leukemia virus (MoLV), MoLV alone or buffer. Short-term fixation in Bouin's fixative was found to be the most effective method for demonstrating p21 in fixed tissue sections. RasHa p21 was found in 5-80% of the induced sarcoma cells, depending on the tissue fixative and antibody dilution. The antigen was localized to the cell membrane and in the cytoplasm. Tumors induced by NIH 3T3 cells transformed with cellular Ha-ras oncogenes had less than 1% immunoreactive tumor cells. Splenic erythroblasts in HaSV-induced erythroblastosis contained membrane antigen as did some reticular cells in lymph nodes draining the sarcomas. Normal tissues of virus-inoculated mice, uninoculated controls or fetuses and selected naturally occurring or induced liver tumors of mice, chemically induced skin tumors of mice, N-nitrosomethylurea-induced mammary tumors of rats, and naturally occurring tumors of F344/NCr rats did not contain immunoreactive p21. Thus, with the use of affinity purified IgG sheep polyclonal antibody to a peptide in RasHa p21, we were able to demonstrate RasHa p21 in tumors and other cells. The degree of immunoreactivity was related to the expected level of p21 expression.

Revertants of Ha-MuSV-transformed MDCK cells express reduced levels of p21 and possess a more normal phenotype

Four subclones of the originally cloned Harvey murine sarcoma virus-transformed Madin Darby canine kidney (MDCK) cells have been isolated. These subclones fall into two general classes. Two subclones have a fibroblastic morphology, have lost the growth requirement for prostaglandin E1 (PGE1), do not respond to glucagon or vasopressin, and, in general, appear transformed. Two other subclones have epithelioid morphologies, are growth-stimulated by PGE1, respond to vasopressin with an increase in intracellular cAMP. We propose that these cells represent revertants to a more non-transformed phenotype. Unlike normal cells, however, these revertants grow under anchorage-independent conditions, express detectable but reduced amounts of the transforming gene product, p21, and grow in nude mice. The appearance of such revertants may be one cause of the observed heterogeneity of tumor cells.

Posttranslational processing of p21 ras proteins involves palmitylation of the C-terminal tetrapeptide containing cysteine-186

The p21 proteins of ras oncogenes are synthesized as precursors in the cytosol. After processing, which involves acylation, the products are associated with the plasma membrane in eucaryotic cells. The p21 overproduced in Escherichia coli, however, is not processed by acylation. A synthetic tetrapeptide of the p21 C terminus is used to identify the acylation site in eucaryotic p21 as cysteine-186. The same peptide of bacterial p21 is not acylated. Although p21 of Harvey murine sarcoma virus-transformed NRK cells can be metabolically labeled with either [3H]palmitate or [3H]myristate, the lipid moiety of the hydrophobic peptide is identified as palmitic acid. We suggest that the enzymatic mechanism for p21 palmitylation may be different from N-terminal myristylation of many other membrane proteins.

The ras oncogene product p21 is not a regulatory component of adenylate cyclase

Harvey (Ha-MSV) and Kirsten (Ki-MSV) murine sarcoma viruses induce tumours in animals and transform various cells in culture because of the expression of the ras oncogene product, p21 (ref. 1). Proto-oncogenes homologous with these genes are highly conserved evolutionarily and activated ras oncogenes have been detected in many human cancers. Whether c-ras oncogenes are directly responsible for human carcinogenesis is uncertain; however, it is clear that p21 mediates virus-induced transformation, although by an unknown mechanism. Epithelial and fibroblast cell lines transformed with Ha-MSV and Ki-MSV express p21 (ref. 8) and exhibit reduced adenylate cyclase activity. Like the guanine nucleotide regulatory proteins, Ns and Ni, which mediate stimulation and inhibition, respectively, of adenylate cyclase, p21 is a membrane-associated GTP binding protein, which exhibits GTPase activity. These similarities suggest that p21 and the adenylate cyclase regulatory proteins are related in cellular function, and that p21 depresses adenylate cyclase by inhibiting the activity of Ns or acting as Ni. We have therefore now examined the structural and functional similarities between p21 and Ns and Ni and find no evidence that p21 regulates adenylate cyclase activity by acting as one of these regulatory proteins.

Biochemical properties of a highly purified v-rasH p21 protein overproduced in Escherichia coli and inhibition of its activities by a monoclonal antibody

The v-rasH oncogene of Harvey murine sarcoma virus encodes a 21,000-dalton p21 protein which has been expressed at a high level as a fusion protein in Escherichia coli. We have purified the p21 to over 90% in purity without the use of any detergent or protein denaturant. The purified p21 possesses full biochemical activities of GTP/GDP binding, autokinase, and GTPase. Scatchard analysis indicates a single class of binding sites with Kd values of 0.83 X 10(-8)M for GTP and 1.0 X 10(-8)M for GDP. The binding site can be specifically labeled with a [3H]GTP photoaffinity analog, P3-(4-azidoanilido)-5' GTP. To probe for the active center of p21, we used a battery of six monoclonal antibodies to p21 to examine their effects on p21 activities. We found that only one monoclonal antibody, Y13-259, was capable of inhibiting both GTP/GDP binding and autokinase enzymatic activities, suggesting that these p21 activities are related activities conferred by a single active center within the p21 molecule. These observations together with the recent finding that microinjection of the same monoclonal antibody into NIH 3T3 cells specifically blocks p21 in vivo function (Mulcahy et al., Nature [London] 313:241, 1985) strongly suggest that p21 in vitro activities are responsible for its cellular function.

Metabolic turnover of human c-rasH p21 protein of EJ bladder carcinoma and its normal cellular and viral homologs

The EJ bladder carcinoma oncogene is activated by a point mutation in the c-rasH proto-oncogene at the 12th amino acid codon. In an attempt to understand the mechanism of oncogenic activation, a comparative study was undertaken to examine the metabolic turnover and subcellular localization of the p21 protein encoded by the EJ oncogene, the viral oncogene, and its normal cellular homolog. Pulse-labeling experiments indicated that both c-ras p21 proteins were synthesized by a very similar pathway, as was observed for the viral p21 protein of Harvey murine sarcoma virus. The pro-p21 proteins were detected in free cytosol, and the processed products were associated with plasma membrane. The intracellular half-life of p21 proteins was determined by pulse-labeling and chasing in the presence of excess unlabeled methionine. Although both p21 proteins of EJ and the normal c-ras genes which are not phosphorylated have a half-life of 20 h, the viral p21 protein of Harvey murine sarcoma virus which includes a phosphorylated form is much more stable in cells, having a half-life of 42 h, apparently due to phosphorylation.

High-level expression in Escherichia coli of enzymatically active Harvey murine sarcoma virus p21ras protein

The gene for the Harvey murine sarcoma virus (Ha-MuSV) p21ras protein was fused to the amino-terminal portion of the bacteriophage lambda cII gene on the expression vector pJL6. The fusion was such that transcription was controlled by the well-regulated phage lambda pL promoter, and translation initiated in the cII gene continued in frame into the ras gene sequences that code for p21. When the pL promoter was derepressed, the Escherichia coli cells harboring the fusion plasmid synthesized 23,000-dalton protein, which represented more than 10 percent of the total cellular protein. This protein was chimeric and contained 14 residues, which were specified by the vector; these residues were followed by all of the amino acids that make up Ha-MuSV p21ras except for four residues at the amino-terminal end. The protein appears similar to Ha-MuSV p21ras in that it undergoes immunoprecipitation by monoclonal antibodies directed toward that protein, binds guanosine diphosphate, and is capable of autophosphorylation.

Loss and restoration of glucagon receptors and responsiveness in a transformed kidney cell line

A kidney cell line (MDCK) retains an adenylate cyclase system sensitive to glucagon, vasopressin, isoproterenol and prostaglandin E1. The stimulatory effect of glucagon on cAMP production was selectively lost in a cloned line derived from MDCK cells transformed by Harvey murine sarcoma virus. Sensitivity to glucagon was largely restored by treatment of the transformed cells with prostaglandin E1 or butyrate. Loss and reappearance of glucagon receptors seemed to be responsible for the observation. The parental MDCK line produced prostaglandins and in the transformed line, this function was abolished. These observations suggest that synthesis of glucagon receptors is controlled by endogenously produced prostaglandin in MDCK cells and that loss of glucagon receptors and their responsiveness in the transformed cells occurs as a consequence of the inability of these cells to synthesize this prostaglandin.

Characterization of the phosphorylation sites and the surrounding amino acid sequences of the p21 transforming proteins coded for by the Harvey and Kirsten strains of murine sarcoma viruses

The transforming protein coded for by the onc gene (v-rasHa) of Harvey murine sarcoma virus (Ha-MuSV) is the 21,000-dalton protein (p21) which is the immediate agent responsible for the virus-induced malignant transformation of normal cells. The p21 proteins of Ha-MuSV and the closely related Kirsten murine sarcoma virus are heavily phosphorylated in vivo. In the partially purified Ha-MuSV p21, the protein shows a guanine nucleotide-binding activity and, in addition, a very unique autophosphorylating activity at a threonine residue using as phosphoryl donor GTP but not ATP. In the present study, we compared the tryptic peptide maps of the Ha-MuSV p21 phosphorylated in vivo and in vitro. The results show that the major phosphorylation site is identical. Since the GTP-specific phosphorylation is very unique and distinct from all other known protein kinases, the present observation suggests that the in vitro enzymatic activity is responsible for the p21 phosphorylation in vivo. We have analyzed the amino acid sequence surrounding the major phosphorylation site of the Ha-MuSV p21 by automated Edman degradations of the tryptic phosphopeptides. Threonine residue 59 from the initiator methionine residue 1 of the p21 protein is the phosphorylated amino acid residue, and the surrounding amino acid sequence is NH2...-Thr-Cys-Leu-Leu-Asp-Ile-Leu-Asp-Thr-Thr(P)-Gly-Gln-Glu-Glu-Tyr-...COOH. The p21 proteins of both the Ha-MuSV and the closely related Kirsten murine sarcoma virus share the same phosphopeptide. The amino acid sequence of the phosphorylation site is distinct from all other known protein kinases.

Nucleotide sequence of the p21 transforming protein of Harvey murine sarcoma virus

Harvey murine sarcoma virus is a retrovirus which transforms cells by means of a single virally encoded protein called p21 has. We have determined the nucleotide sequence of 1.0 kilobase in the 5' half of the viral genome which encompasses the has coding sequences and its associated regulatory signals. The nucleotide sequence has identified the amino acid sequence of two additional overlapping polypeptides which share their reading frames and the carboxyl termini with p21 but which contain additional NH2-terminal amino acids.

Identification of a precursor in the biosynthesis of the p21 transforming protein of harvey murine sarcoma virus

The p21 transforming protein coded for by the v-ras gene of Harvey murine sarcoma virus (Ha-MuSV) migrates as a doublet band between 21,000 and 23,000 daltons during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The lower band of the doublet is designated p21, and the upper band is designated pp21 since it comigrates with the phosphorylated form of p21. By pulse-labeling with [35S] methionine, we detected a p21 precursor, pro-p21, which migrated as if it was approximately 1,000 daltons larger than p21. The precursor-product relationship was established by pulse-chase experiments with [25S] methionine in the presence of 100 micrograms of cycloheximide per ml, which inhibited all de novo protein biosynthesis. Within 4 h, pro-p21 was completely chased into p21, and during the next 24 h pp21 accumulated. Thus, formation of pp21 from p21 did not require de novo protein synthesis. By subcellular fractionation into cytosol amd membrane fractions, we found that pro-p21 was synthesized in a non-membrane-bound state and that shortly after its complete synthesis, the p21 product was associated with the membrane fraction. By selective cleavage of p21 at a unique aspartic acid-proline residue with 70% formic acid or with Staphylococcus aureus V8 protease, we found that the intramolecular site of pro-p21 processing was located in the C-terminal portion of the pro-p21 molecule. The possibilities that the precursor was involved in the assembly of p21 into the plasma membrane and, alternatively, that the processing was a step in the activation of p21 biochemical activities are discussed.

The p21 src genes of Harvey and Kirsten sarcoma viruses originate from divergent members of a family of normal vertebrate genes

The Harvey and Kirsten strains of murine sarcoma virus encode enzymatically and serologically related p21 src proteins which are required for virally mediated cellular transformation. The genes in each virus encoding p21 show such extensive divergence from each other that cloned probes from these genes detect distinct sets of cellular genes in the DNA from several vertebrate species. These data suggest that cellular p21 sarc genes constitute a divergent family of vertebrate genes that can regulate the growth of cells.

Markedly elevated levels of an endogenous sarc protein in a hemopoietic precursor cell line

The src gene product of Harvey murine sarcoma virus is a 21,000-dalton guanine nucleotide-binding protein. We have recently shown that a wide variety of vertebrate cell strains and cell lines express much lower levels of an endogenous p21 immunologically related to the Harvey murine sarcoma virus-coded p21. In this report, we have examined the levels of endogenous p21 in a unique hemopoietic precursor cell line, 416B, which was originally described as a continuous cell line of a hemopoietic stem cell, CFU-S. The currently available 416B cells express markedly elevated levels of endogenous p21. The level of endogenous p21 in the 416B cells is 5- to 10-fold higher than the level of p21 in Harvey murine sarcoma virus-infected cells and more than 100 times higher than the level of endogenous p21 that we have observed in a variety of other fresh or cultured cells. The results indicate that marked regulation of the levels of an endogenous sarc gene product can occur, and speculation about a possible role for endogenous p21 in normal hemopoietic stem cells is discussed.