Non-surgical and guided-bone-regeneration surgical management of Type-3b dens invaginatus with an apico-marginal defect: A case report

BACKGROUND

Dens invaginatus (DI), an unusual developmental anomaly is a challenge for the operating dentist with regard to its diagnosis and treatment. This case report presents the successful management of a Type-3b DI in a permanent maxillary lateral incisor associated with a large radicular cyst and communicating apico-marginal defect (Von Arx type IIb).

METHODS AND RESULTS

A 19-year-old female patient reported pain and palatal swelling. During the clinical examination, tooth #12 exhibited tenderness to percussion, and presented a deep periodontal pocket depth (PPD) of 12 mm, along with grade I mobility. Radiographic examination revealed a large peri-radicular radiolucency with atypical tooth morphology. Cone beam computed tomography clarified the complicated root canal anatomy to be Type-3b DI associated with an apico-marginal defect. The case was managed successfully by non-surgical endodontic therapy followed by surgical intervention utilizing a guided bone regenerative (GBR) approach. Eighteen-month follow-up showed an asymptomatic and functional tooth with a significant reduction in pocket depth. The periapical radiographs showed continued healing of the osseous defect.

CONCLUSIONS

The successful healing outcome of a challenging case, characterized by a complex DI morphology, a large peri-radicular lesion, a through-and-through defect, and a combined endodontic-periodontal apico-marginal defect was achieved through accurate diagnosis, treatment planning, and execution using contemporary endodontic and periodontal treatment techniques. The application of GBR techniques during the surgical phase of treatment may have contributed to the improved regenerative healing outcome in this case, which was initially considered prognostically questionable.

KEY POINTS

Why is this case new information? Type-3b DI exhibits a complex root canal structure, each case displaying unique characteristics, necessitating a case-specific treatment plan. In this case report the Type-3b DI morphology was associated with a large peri-radicular, through and through defect and combined endodontic periodontal apico-marginal defect. The treatment approach involved incorporating guided bone regenerative (GBR) principles during the surgical phase. This case report contributes to the existing evidence on the diagnosis and successful management of Type-3b DI with a concurrent apico-marginal defect. What are the keys to successful management of this case? The successful management of a prognostically challenging case was achieved through a closely integrated multidisciplinary coordination between the endodontist and periodontist. Utilization of contemporary techniques and tools contributed to the successful management The use of three-dimensional radiological examination through cone beam computed tomography enabled a precise preoperative assessment, facilitating the formulation of a treatment plan for managing both the Type-3b DI morphology and the associated peri-radicular lesion. Employing GBR techniques in peri-radicular surgery may have assisted in the healing of through-and-through periapical defects with concurrent apico-marginal defects (Von Arx type IIb). What are the primary limitations to the success of this case? A complex root canal anatomy associated with Type-3b DI morphology A large peri-radicular through and through defect with concurrent apico-marginal defect. Difficulty in weekly and long-term follow-up of the patient.

Eco-safe composite edible coating of hydrocolloids with papaya leaf extract improves postharvest quality and shelf life of papaya fruit under ambient storage

Papaya postharvest management using low-temperature storage is discouraged as it is a tropical fruit. Extensive research is going on to preserve papaya quality at ambient storage using edible coatings and its composites. The present investigation examined the effects of an eco-safe composite edible coating consisting of hydrocolloid carboxymethyl cellulose (CMC) (1%), guar gum (1.5%), xanthan gum (0.3%), and Gum Arabic (10%) combined with papaya leaf extract (PLE) (1:1 ratio by volume) applied as dip treatment on "Red Lady" papaya fruit at ambient storage condition. Among all the attempted treatments, "PLE incorporated with CMC (1%)" was found to be the best, as the treated fruit exhibited the highest levels of biochemicals, whereas the lowest levels of physiological and enzymatic activity, which positively affected the shelf life. The "CMC + PLE" treatment enhanced the fruit gloss score by 70.1%, phenolics by 6.1%, ascorbic acid by 22.3%, total carotenoid content by 7.4%, and fruit predilection score by 22.0% over the control fruit. However, it lowered (controlling) the physiological loss in weight by 51.0%, decay incidence by 66.6%, and polygalacturonase and pectin methylesterase activity by 24.92% and 35.29%, respectively, over control. Moreover, this treatment exhibited the highest fruit purchase predilection score and prolonged the storage life for >3 days on the physiological loss standard basis (≤10%). This study indicates that "CMC (1%) with PLE (1:1)" composite coating application on papaya under ambient conditions might be an effective, environmentally friendly, and health-friendly way to retain the quality and extend the storage life.

Interacting Genetic Lesions of Melanoma in the Tumor Microenvironment: Defining a Viable Therapy

Melanoma is the most aggressive form of skin cancer with an estimated 106,110 newly diagnosed cases in the United States of America in 2021 leading to an approximated 7180 melanoma-induced deaths. Cancer typically arises from an accumulation of somatic mutations and can be associated with mutagenic or carcinogenic exposure. A key characteristic of melanoma is the extensive somatic mutation rate of 16.8 mutations/Mb, which is largely attributed to UV exposure. Bearing the highest mutational load, many of them occur in key driver pathways, most commonly the BRAFV600E in the mitogen-activated protein kinase (MAPK) pathway. This driver mutation is targeted clinically with FDA-approved therapies using small molecule inhibitors of oncogenic BRAFV600E and MEK, which has greatly expanded therapeutic intervention following a melanoma diagnosis. Up until 2011, therapeutic options for metastatic melanoma were limited, and treatment typically fell under the spectrum of surgery, radiotherapy, and chemotherapy.Attributed to the extensive mutation rate, as well as having the highest number of neoepitopes, melanoma is deemed to be extremely immunogenic. However, despite this highly immunogenic nature, melanoma is notorious for inducing an immunosuppressive microenvironment which can be relieved by checkpoint inhibitor therapy. The two molecules currently approved clinically are ipilimumab and nivolumab, which target the molecules CTLA-4 and PD-1, respectively.A plethora of immunomodulatory molecules exist, many with redundant functions. Additionally, these molecules are expressed not only by immune cells but also by tumor cells within the tumor microenvironment. Tumor profiling of these cell surface checkpoint molecules is necessary to optimize a clinical response. The presence of immunomodulatory molecules in melanoma, using data from The Cancer Genome Atlas and validation of expression in two model systems, human melanoma tissues and patient-derived melanoma cells, revealed that the expression levels of B and T lymphocyte attenuator (BTLA), TIM1, and CD226, concurrently with the BRAFV600E mutation status, significantly dictated overall survival in melanoma patients. These molecules, along with herpesvirus entry mediator (HVEM) and CD160, two molecules that are a part of the HVEM/BTLA/CD160 axis, had a higher expression in human melanoma tissues when compared to normal skin melanocytes and have unique roles to play in T cell activation. New links are being uncovered between the expression of immunomodulatory molecules and the BRAFV600E genetic lesion in melanoma. Small molecule inhibitors of the MAPK pathway regulate the surface expression of this multifaceted molecule, making BTLA a promising target for immuno-oncology to be targeted in combination with small molecule inhibitors, potentially alleviating T regulatory cell activation and improving patient prognosis.

Abstract P5-03-06: Novel targets of breast cancer associated with inflammatory tumor microenvironment

Breast cancer affects one in eight women in the USA. Considerable progress in the identification of genetic lesions and their modulation has resulted in newer therapies making breast cancer a manageable disease. However, triple negative breast cancer is still difficult to treat and warrants a search for newer targets. To this end, we focused our attention towards the modulation of the breast cancer epithelium by other cell types such as the endothelial cells and the macrophages. The migratory macrophages and the estrogen sensitive migratory endothelial progenitor cells (EPCs) constitute the cellular milieu within the tumor microenvironment which continuously modulates breast cancer epithelium. We analyzed the interactions of the breast cancer cell lines (MCF-7 and MDA-MB-231) with the highly proliferative human umbilical cord derived CD133+/CD34+/VEGFR-2+ EPCs and M1 polarized macrophages (activated THP-1 cell line) in two separate in vitro studies. The readouts were cell proliferation, changes in epithelial to mesenchymal transition (EMT), and cellular differentiation. We observed morphological and cellular growth changes in the EPCs on treatment with conditioned medium (CM) generated from breast cancer cells, consistent with vasculogenesis and in vitro tubulogenesis. Both, MDA-MB-231 and MCF-7 CM, treatments resulted in enhanced EPCs proliferation and differentiation. However, the differentiation patterns were distinct, with MCF-7 CM increasing the number of cell clusters, whereas MDA-MB-231 CM increasing the number of adherent spindle shaped cells. The paracrine interaction was also assessed with M1 polarized macrophages. We observed decreased cell viability in MCF-7 and MDA-MB-231 cells following activated THP-1 CM and exosome treatments. Analysis of exosomes from activated THP-1 indicated an upregulation of 13 miRNAs compared to unactivated THP-1. The miRNA hsa-miR-146a-5p had the highest upregulation (44 fold increase). This specific miRNA has been observed in senescent cell and it inhibits cell proliferation, suggesting a possible mechanism for exosome-associated growth inhibition. The analysis of the paracrine interactive mediators between breast cancer cells, EPCs, and M1 polarized macrophages is likely to yield viable novel clinically translatable therapeutic targets.

Citation Format: Tiwari RK, Ben Rahoma G, Tuli N, Bednarczyk R, Maniyar RR, Chakraborty S, Singh S, Mittelman A, Geliebter J. Novel targets of breast cancer associated with inflammatory tumor microenvironment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-03-06.

Interlinking of hypoxia and estrogen in thyroid cancer progression

Estrogen aids in neo-vascularization of various tumors during hypoxic conditions, however the role of estrogen within the hypoxic environment of thyroid cancer is not known. In a series of experimentations, using human thyroid cancer cells, we observed that estrogen and hypoxia modulate the hypoxia inducible factor-1 (HIF-1) signaling which is abrogated by the anti-estrogen fulvestrant and the HIF-1 inhibitor YC-1 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole). Furthermore, we found that the conditioned medium from estrogen treated thyroid cancer cells lead to enhanced migration and tubulogenesis of human umbilical vein endothelial cells (HUVECs) which is abrogated by HIF-1 inhibitor. These findings, in addition to our previous and other scientific literature data, lead us to conclude that estrogen and hypoxia are interlinked in thyroid cancer and can equally modulate epithelial-endothelial cell interactions by mediating key cellular, metabolic and molecular processes of thyroid cancer progression. We believe that the hormonal component and cellular adaptation to oxygen tension of cancer cells are functionally equivalent with a cellular transition that can be exploited clinically for a combinational approach for thyroid cancer treatment involving antiestrogens as well as anti-hypoxic agents.

A novel study on carpet-dye-induced dermatitis and other changes in Rattus norvegicus

It is known that humidity enhances the growth of mites in carpets, mattresses and other household items. The association between exposure to house dust and diseases such as asthma, chronic rhinitis and atopic dermatitis has been shown in many individuals. Large quantities of carpet dyes are used in carpet industry located in Eastern Uttar Pradesh India. Nearly 90% of the carpets are manufactured in Eastern Uttar Pradesh and remaining 10% is produced in Kashmir and other places of India. Therefore, this area is important in huge dyeing and washing industry in which nearly 760 metric tons of dyes and dye supporting chemicals as well as washing chemicals are used per year. Present study has been conducted to see the adverse health effects of carpet dye black T supra which is being greatly used in carpet industry. In the present study, Gram mixed with 20 mg kg(-1) of b.wt. day(-1) sub-lethal dose of Black T Supra carpet dye was fed to Rattus norvegicus for three months and the symptoms of dermatitis in the form of hair fall in patches on surface of body started from fifth week onward. The area of patches of hair fall increased between 6-12th weeks. In controls, such effect was not observed. In addition, a little increase in body weight, cataract in eyes and desperate walking in experimental animals were observed after fifth week of feeding Black T Supra dye. In some cases, the correlation between exposure to carpet dye black T supra and symptoms is obvious.

Synthesis, molecular structure, hydrogen-bonding, NBO and chemical reactivity analysis of a novel 1,9-bis(2-cyano-2-ethoxycarbonylvinyl)-5-(4-hydroxyphenyl)-dipyrromethane: a combined experimental and theoretical (DFT and QTAIM) approach

The spectroscopic analysis of a newly synthesized 1,9-bis(2-cyano-2-ethoxycarbonylvinyl)-5-(4-hydroxyphenyl)-dipyrromethane (3) has been carried out using (1)H NMR, UV-Visible, FT-IR and Mass spectroscopic techniques. All the quantum chemical calculations have been carried out using DFT level of theory, B3LYP functional and 6-31G(d,p) as basis set. Thermodynamic parameters (H, G, S) of all the reactants and products have been used to determine the nature of the chemical reaction. The chemical shift of pyrrolic NH in (1)H NMR spectrum appears at 9.4 ppm due to intramolecular hydrogen bonding. TD-DFT calculation shows the nature of electronic transitions as π→π(*) within the molecule. A combined experimental and theoretical vibrational analysis designates the existence of H-bonding between pyrrole N-H as proton donor and nitrogen of cyanide as proton acceptor, therefore, lowering in stretching vibration of NH and CN. To investigate the strength and nature of H-bonding, topological parameters at bond critical points (BCPs) are analyzed by 'Quantum theory of Atoms in molecules' (QTAIMs). Natural bond orbitals (NBOs) analysis has been carried out to investigate the intramolecular conjugative and hyperconjugative interactions within molecule and their second order stabilization energy (E((2))). Global electrophilicity index (ω=4.528 eV) shows that title molecule (3) is a strong electrophile. The maximum values of local electrophilic reactivity descriptors (fk(+),sk(+),ωk(+)) at vinyl carbon (C6/C22) of (3) indicate that these sites are more prone to nucleophilic attacks.

A combined experimental and theoretical (DFT and AIM) studies on synthesis, molecular structure, spectroscopic properties and multiple interactions analysis in a novel ethyl-4-[2-(thiocarbamoyl)hydrazinylidene]-3,5-dimethyl-1H-pyrrole-2-carboxylate and its dimer

In the present work, ethyl-4-[2-(thiocarbamoyl)hydrazinylidene]-3,5-dimethyl-1H-pyrrole-2-carboxylate (3) has been synthesized and characterized by (1)H NMR, UV-Vis, FT-IR and Mass spectroscopy. The formation of the compound and its properties have also been evaluated by quantum chemical calculations using DFT, B3LYP functional and 6-31G(d,p) as basis set. The calculated thermodynamic parameters show that the formation of 3 is an exothermic and spontaneous reaction at room temperature. (1)H NMR chemical shifts are calculated using gauge including atomic orbitals (GIAO) approach in DMSO-d6 as solvent. Time dependent density functional theory (TD-DFT) is used to calculate the energy (E), oscillator strength (f) and wavelength absorption maxima (λ(max)) of various electronic transitions and their nature within the molecule. NBO analysis is carried out to investigate the charge transfer or charge delocalization in various intra- and intermolecular interactions of molecular system. The vibrational analysis indicates the formation of dimer in the solid state by intermolecular heteronuclear hydrogen bonding (NH···O). Topological parameters at bond critical points (BCP) are calculated to analyze the strength and nature of various types of intra and intermolecular interactions in dimer by Bader's 'Atoms in molecules' AIM theory in detail. The binding energy of intermolecular multiple interactions is calculated to be 15.54 kcal/mol, using AIM calculation. The local reactivity descriptors such as Fukui functions (f(k)(+),f(k)(-)), local softnesses (s(k)(+),s(k)(-)) and electrophilicity indices (ω(k)(+),ω(k)(-)) analyses are performed to determine the reactive sites within molecule.

Molecular structure, heteronuclear resonance assisted hydrogen bond analysis, chemical reactivity and first hyperpolarizability of a novel ethyl-4-{[(2,4-dinitrophenyl)-hydrazono]-ethyl}-3,5-dimethyl-1H-pyrrole-2-carboxylate: a combined DFT and AIM approach

A new ethyl-4-{[(2,4-dinitrophenyl)-hydrazono]-ethyl}-3,5-dimethyl-1H-pyrrole-2-carboxylate (EDPHEDPC) has been synthesized and characterized by FT-IR, (1)H NMR, UV-vis, DART-Mass spectroscopy and elemental analysis. Quantum chemical calculations have been performed by DFT level of theory using B3LYP functional and 6-31G(d,p) as basis set. The (1)H NMR chemical shifts are calculated using gauge including atomic orbitals (GIAO) approach in DMSO as solvent. The time dependent density functional theory (TD-DFT) is used to find the various electronic transitions and their nature within molecule. A combined theoretical and experimental wavenumber analysis confirms the existence of dimer. Topological parameters such as electron density (ρ(BCP)), Laplacian of electron density (nabla(2)ρ(BCP)), kinetic electron energy density (G(BCP)), potential electron density (V(BCP)) and the total electron energy density (H(BCP)) at bond critical points (BCP) have been analyzed by Bader's 'Atoms in molecules' AIM theory in detail. The intermolecular hydrogen bond energy of dimer is calculated as -12.51 kcal/mol using AIM calculations. AIM ellipticity analysis is carried out to confirm the presence of resonance assisted intra and intermolecular hydrogen bonds in dimer. The calculated thermodynamic parameters show that reaction is exothermic and non-spontaneous at room temperature. The local reactivity descriptors such as Fukui functions (f(k)(+), f(k)(-)), local softnesses (s(k)(-), s(k)(+)) and electrophilicity indices (ω(k)(+), ω(k)(-)) analyses are performed to determine the reactive sites within molecule. Nonlinear optical (NLO) behavior of title compound is investigated by the computed value of first hyperpolarizability (β(0)).

Surgical management of Pott's disease of the spine in pediatric patients: A single surgeon's experience of 8 years in a tertiary care center

Study Design:

A retrospective, case study of 64 pediatric patients who underwent spinal surgery for Pott's spine and have minimum 6 months follow-up.

Objective:

The aim of this study was to evaluate the surgical management and outcome of 64 pediatric Pott's spine cases operated by single surgeon over last 8 years, with a minimum follow-up of 6 months. The prognostic significance and the outcome of the demographic factors, location of the disease, and its surgical approach were also evaluated in these patients.

Materials and Methods:

The data collected retrospectively from the institute's record case sheets of the 64 pediatric patients with Pott's disease of the spine, operated between 2002 and 2010 in the Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Lucknow, were analyzed. The study population consisted of 40 male and 24 female pediatric patients. Clinical findings included back pain, paraparesis, kyphosis, fever, sensory disturbance, and bowel and bladder dysfunction.

Results:

The most common region of Pott's disease was the thoracic region [21/64 (33%)] followed by craniovertebral junction (CVJ) [17/64 (27%)]. At presentation, all of the patients had neurological features of spinal cord compression. All patients were treated with antituberculous chemotherapy which was continued after the surgical intervention also. Transthoracic surgical approach [18/64 (28%)] was the most frequently required surgery followed by transoral decompression with posterior fusion [12/64 (19%)] depending on the site of disease and compression of neuraxis. Initially, more than two-third of the patients were in poor grade of Kumar and Kalra scoring as well as modified Kumar and Kalra scoring, which were reduced to about one fifth after the surgical intervention, and the outcome was good as the condition of 46 patients (72%) improved significantly.

Conclusion:

Currently, treatment of spinal tubercular infections requires a multidisciplinary team that includes infectious diseases experts, neuroradiologists, and spine surgeons. The key to successful management is early detection and timely and judicious surgical intervention, the decision of which needs to be taken in view of clinicoradiological compression of the spinal cord and nerve roots, age of the patient and responsiveness of ATT.

Pre-clinical toxicology and pathology of 9-(2′-hydroxyethylamino)-4-methyl-1-nitroacridine (C-1748), a novel anti-cancer agent in male Beagle dogs

We have developed a group of 4-substituted-1-nitroacridines with potent anti-tumor activity against prostate cancer and less toxic than parent 1-nitroacridines. The most active 9-(2'-hydroxyethylamino)-4-methyl-1-nitroacridine (C-1748) was selected for pre-clinical studies. The current study was undertaken to evaluate clinical and/or morphological adverse effects of C-1748 as a single intravenous dose at concentrations ranging from 0.16 to 4.6 mg/kg administered to male Beagle dogs. The maximum tolerated dose was 1.5 mg/kg. Emesis was observed in all groups lasting an average of 30 min to 12 h post-dosing. At high dose, extreme aggression was observed in one dog followed by disorientation and depression lasting for 48 h a frequent observation with chemotherapy. Reductions in platelets and white blood cells were observed which was similar to that seen with other chemotherapeutic agents. A compensatory hyperplasia of lymph nodes and a transient and limited extravasation in the intestinal mucosa were also observed. Increases in aspartate aminotransferase, alkaline phosphatase and creatine phosphokinase were transient with normal levels restored by day 9. These enzyme increases were accompanied by epithelial hypertrophy of larger bile ductules in the periportal triads of the liver. The low toxicity profile and high tumor target activity make this novel class of drug a promising chemotherapeutic agent.

Pilot Study Using SELDI-TOF−MS Based Proteomic Profile for the Identification of Diagnostic Biomarkers of Thyroid Proliferative Diseases

Biomarkers for thyroid cancer (TCa) lack specificity. To develop TCa specific biomarkers, SELDI-TOF-MS was used to examine the proteomic profile of biopsies obtained from papillary TCa along with adjacent normal tissue. Sixty-three potential biomarkers were categorized by univariate analysis into single biomarker candidates and segregated by multivariate analysis into normal and cancerous groups. Our studies demonstrate the sensitivity and reproducibility of this approach to detect biomarkers for TCa.

Anti-carcinogenic and anti-metastatic properties of indole-3-carbinol in prostate cancer

Indole-3-carbinol (I3C), a compound present as glucobracissin in cruciferous vegetables has anticancer activities which is in line with some of the epidemiological evidence that suggests a beneficial effect of consumption of cruciferous vegetables on cancer incidence and progression. The precise target of indole-3-carbinol has not been determined. We examined the effect of I3C on prostate cancer in a well-defined R3327 model using Copenhagen rats and the transplantable cell line, MAT-LyLu. This cell line derived from a tumor in Copenhagen rats is androgen independent and metastasizes to the lung and lymph nodes. Tumors were induced in Copenhagen rats by injecting MAT-LyLu subcutaneously and the animals treated with I3C that was administered either intraperitoneally or intravenously, in order to achieve maximal systemic exposure. This was a departure from the traditional chemopreventive route of indole-3-carbinol where the compound was incorporated in the diet. Our results indicate that I3C inhibited the incidence, growth and metastases of MAT-LyLu cells and both i.p. and i.v. injections of I3C were equally effective. Statistical analysis (Kaplan-Meier curves) clearly indicates a tumor-free and overall survival benefit as a result of treatment with I3C. These studies show for the first time that I3C in an injectible form has anti-prostate cancer activity.

Effects of repeated haemolymph withdrawals on haemocyte counts and moulting in lemon-butterfly, Papilio demoleus L

Total and differential haemocyte counts following repeated haemolymph withdrawals were made in V instar larvae of P. demoleus. While total count showed a steady reduction reaching its lowest in prepupal stage, much variation was observed in the relative percentage of various cell types. Further, the repeated removals of haemolymph from V instar larvae and pupae affected imaginal moulting and lengths of body and wings in adult butterflies.

Peptide mimotopes of oncoproteins as therapeutic agents in breast cancer

Generation of an immune response to oncoproteins can lead to a cancer specific protective immunity. Several such oncoproteins are being examined as tumor targets with mixed results. We are evaluating the clinical utility of synthetic peptides that would mimic the antigen immunologically and elicit a tumor specific immune response. HER-2/neu, an oncoprotein whose expression in breast cancer is associated with poor prognosis, lower disease free-survival and a propensity for metastases was chosen as a model. Antibodies, Ab2, Ab4 and Ab5 directed towards the extracellular domain of HER-2/neu were reacted to peptides from two synthetic phage display peptide libraries, LX-8 (12-mer peptide library containing disulfide bridge) and X-15 (linear 15-mer). The isolated peptides were sequenced and characterized for ability to produce high titer antibodies and cross-reactivity. The peptides isolated did not show any sequence homology to protein databases but did show a hierarchy of immunogenic epitopes. Antibodies generated against peptides selected against the same antibody Ab2 or Ab4 showed affinity variation. Phages selected against Ab2 were also able to compete with binding of Ab2 to HER-2/neu. These results validate our hypothesis that synthetic peptides that mimic the antigenic epitope of oncoprotein can be generated and their clinical utility rests on devising a screening mechanism to identify peptides that can elicit an immune response directed to the oncoprotein and if possible its antigenic variants.

Induction of heat shock protein gp96 by immune cytokines

Cytokines play a major role in regulating both humoral and cell-mediated immune responses. Recent advances in our understanding of cell-mediated immune responses have focused on the antigen presentation machinery and the proteins in the endoplasmic reticulum (ER). These proteins help the formation and stabilization of the major histocompatibility complex (MHC)-peptide interaction. A 96-kDa, ER-resident glycoprotein (gp96) is being evaluated as a therapeutic agent in cancer because of its ability to associate with a vast number of cellular peptides irrespective of size or sequence. Because the antigen presentation complex is assembled in the ER and a number of ER-resident proteins are modulated by cytokines, it is important to examine the regulation of gp96 in response to immune cytokines interferon gamma (IFN-gamma), and interleukin 2 (IL-2). Defects in signaling pathway in either of the cytokines can result in suboptimal immune response. We examined the effect of the cytokines IFN-gamma and IL-2 on the induction of gp96 in different cancer cell lines and examined the induction of DNA-binding proteins that recognize gamma interferon-activating sequence (GAS), present in the promoter region of gp96. The induction of GAS binding protein correlated with the induction of STAT 1 protein, a transcriptional regulator and mediator of IFN-gamma-mediated gene expression. The use of cytokines in inducing gp96 levels may have significance in maintaining high levels of gp96 for a sustained immune response.

Abrogation of estrogen-mediated cellular and biochemical effects by indole-3-carbinol

The use of naturally occurring phytoantiestrogens for prevention and therapy of breast cancer is an alternative to synthetic antiestrogens. We have been examining the mechanism of action of the antiestrogen indole-3-carbinol (I3C), a constituent of compounds present in cruciferous vegetables. I3C abrogates the cell-proliferative effect of 17 beta-estradiol (E2), as observed in several different estradiol-responsive breast cancer cell lines and isolated cell clones. Modulation of E2 activity by I3C, in part, was by the induction of the 2-hydroxylation pathway, one of the two competing hydroxylation pathways of estrone conversion that resulted in the formation of metabolites with antiestrogenic properties. I3C-mediated induction of the 2-hydroxylation pathway correlated with a selective induction of cytochrome P-450 1A1 by I3C in E2-responsive human breast cancer cells. Induction of neither the 2-hydroxylation pathway nor cytochrome P-450 1A1 was observed in estrogen-nonresponsive human breast cancer cells. This selective effect warranted a further search for biochemical targets of I3C related to E2 function. To this end, we observed that E2-mediated phosphorylation of the estrogen receptor is inhibited by I3C. Our results are consistent with the hypothesis that I3C exerts its antiestrogenic effect by intervention in the E2-estrogen receptor signal transduction pathways and by alterations in E2 metabolism that resulted in the formation of metabolites with antiestrogenic activity.

Haemopoietic organs and effect of their ablation on total haemocyte count in lemon-butterfly, Papilio demoleus L

The haemopoietic organs in Vth instar larvae of P. demoleus are in the form of thin transparent cellular sheets, closely wrapped around the base of each wing-pad. Three cell types viz; prohaemocytes, plasmatocytes and oenocytoids appear to be derived from these organs and their ablation caused a reduction in cell number which, in turn, revealed that the haemocytes in general are derived both from the haemopoietic organs as well as from the circulating blood cells.

Multiple molecular targets of indole-3-carbinol, a chemopreventive anti-estrogen in breast cancer

The mechanism of action of the anti-estrogen indole-3-carbinol (I3C), present in cruciferous vegetables, is being examined in our laboratory with a view to promote the use of this naturally occurring chemopreventive as an alternative to synthetic anti-estrogens in human breast cancer. Our previous results clearly demonstrated that despite its low affinity for the estrogen receptor (ER), I3C abrogated estradiol-mediated cellular and biochemical effects in estradiol-responsive cells and tissues. In an earlier report, we identified ER phosphorylation as one of the targets of I3C, and in this communication we describe the consequence of inhibition of ER phosphorylation. Estradiol-induced DNA-binding proteins that bound to several DNA-responsive elements were inhibited by I3C and this effect was not at the level of DNA-protein physical interaction as inclusion of I3C in vitro in the reaction mix did not affect the binding. We analyzed the spectrum of genes induced by estradiol and modulated and/or intercepted by I3C. Our results conclude that although estradiol-mediated functions are affected by I3C, its biochemical targets are multiple and some of these may be modulated by the oligomeric products of I3C.

Proteasome inhibitors differentially affect heat shock protein response in cancer cells

The heat shock proteins (HSPs) are molecular chaperones that are emerging as biochemical regulators of cell growth, apoptosis, protein homeostasis and intracellular targeting of peptides. The immunological function of the HSPs are imparted by tissue specific peptides associated with the HSPs and as such autologous cancer derived HSP-peptide complexes are unique therapeutic agents. Since a majority of the intracellular peptides are generated by the proteasome, we examined the consequence of abrogation of proteasome function by proteasome inhibitors (PIs) such as Lactacystin, MG-132 and LLM on the growth and induction profile of HSP70 and gp96 using hematopoietic, lymphoid, and epithelial derived cancer cell lines. The effect on growth was measured by the XTT assay and induction of the heat shock proteins by western blot analyses using HSP70 and gp96 specific antibodies. Of the PIs tested, cancer cells, were most sensitive to MG-132 and least sensitive to LLM. MG-132 also showed a 10-fold differential sensitivity between estrogen receptor positive, (ER+) MCF-7 cells and negative cells, (ER-) MDA-MB-231. Induction of heat shock proteins, gp96 and HSP70 was, however, noted in response to LLM. Since LLM exhibited minimal cytotoxic effect, metabolic stress that results in induction of HSPs may not be translated in cell growth inhibition and that there may exist a cell-type specific phenomenon in the HSP response to PI mediated metabolic stress.

Endocrine characteristics of human breast epithelial cells, MCF-10F

MCF-10F is a spontaneously immortalized nontransformed human breast epithelial cell line which does not grow in soft agar or form tumors in nude mice. Though the presence of estrogen receptors has not been found in these cells, they can metabolize estradiol very efficiently. The present study describes the endocrine characteristics of this cell line with respect to growth response to estradiol and its metabolites, estradiol metabolism and aromatase activity. MCF-10F cells were growth stimulated by 16alpha-hydroxyestrone and estriol, whereas, estradiol and other estradiol metabolites did not affect cell proliferation. The constitutive level of 16alpha-hydroxyestrone, a metabolite of estradiol biotransformation that has been associated with enhanced carcinogenesis in several animal, cell and tissue culture models, was a hundredfold higher in the non-transformed MCF-10F cells than in the transformed MCF-7 cells. Treatment with the carcinogen, dimethylbenz(a)anthracene (DMBA), however, did not upregulate 16alpha-hydroxylation as was observed in transformed MCF-7 cells. MCF-10F cells also had no detectable aromatase activity though the level of 17-oxidation was unusually high as compared with MCF-7 cells. Our results using the non-transformed MCF-10F cells as a model system suggests that the presence of high level of 16alpha-hydroxyestrone, a metabolite previously shown to be associated with malignant phenotype, may not be sufficient for breast cancer transformation.

Preventive and therapeutic effect of tumor derived heat shock protein, gp96, in an experimental prostate cancer model

Tumor-derived purified heat shock protein (HSP), gp96, has tumor protective effect in a number of experimental cancers that include fibrosarcoma, hepatoma, and spindle cell carcinoma. The rationale for using gp96 as a vaccinating agent stems from the discovery that HSPs, including gp96, chaperone antigenic peptides for eventual recognition and elicitation of an immune response. The immune response generated by the HSP-peptide complex is specific to the tumor from which they are derived. The long-term objective of our studies is to develop a vaccine for primary and metastatic prostate cancer using tumor-derived HSPs. In the present study, we report our results on the tumor protective effect of irradiated Dunning G cells, or purified preparations of g96-peptide complexes as a tumor vaccine. Tumor incidence, latency, and tumor growth were the end points of measurement. Tumor bearing Copenhagen rats, made free of disease by surgical resection of the tumors resisted a fresh challenge of live Dunning G tumor cells. Vaccination with irradiated whole cells failed to elicit any resistance to tumor growth. Vaccination with Dunning G derived purified gp96-peptide complexes delayed both incidence and growth of Dunning G induced tumors. Inhibition of tumor growth was observed when gp96 was administered after tumor induction. Our data suggests that tumor derived gp96-peptide complexes can be used as an effective prophylactic and therapeutic agent even in poorly immunogenic cancer such as prostate cancer. Further investigations will determine specificity of action and define the immunological determinants and experimental conditions for its optimal activity.

Periodicity in marine phosphorus burial rate

There have been arguments both for and against a periodicity of 26-33 million years (Myr) in terrestrial and extraterrestrial records. The best way to identify such periodicity is the analysis of geomarine evolutionary records. We have analysed the marine sedimentary phosphorus burial rate (PBR), as fluctuations in this rate are strong indicators of the coupling of climate, continental weathering and ocean primary productivity. We find a statistically significant harmonic component of 33 +/- 3 Myr against the estimated robust background noise spectrum, supporting the idea that geomarine processes are cyclic.

Anti-tumor effects of PC-SPES, an herbal formulation in prostate cancer

Prostate cancer is the most common cancer amongst males in developed countries. Surgical removal of the prostate effectively cures the primary disease but the metastatic disease is refractory to most forms of chemotherapy. There is a clinical need to develop novel treatment strategies that exploit the mode of action of both conventional and alternative drugs/medicinal plants. We have been investigating the anti-proliferative and anti-tumor effects of an herbal preparation termed PC-SPES (patent pending, US serial number 08/697, 920) which is a refined powder of eight different medicinal plants. PC-SPES administered as a food supplement caused a dramatic decrease in prostate specific antigen levels in some prostate cancer patients with advanced disease. These preliminary clinical findings laid the foundation for a program to examine the in vitro and in vivo effects of PC-SPES, and identify the active component in this mixture so that a standardized treatment regimen can be formulated. In this communication, we report the anti-tumor effects of PC-SPES incorporated in the diet utilizing a well studied Dunning R3327 rat prostate cancer model. Dietary PC-SPES at levels of 0.05% and 0.025% did not exhibit any toxicity and no significant difference in food intake was noted at the end of six weeks. Dose dependent inhibitory effect of dietary PC-SPES was observed on both tumor incidence (P=0. 01) and rate of tumor growth when tumors were induced in syngeneic Copenhagen rats by intradermal injections of MAT-LyLu cells that are known to metastasize in the lung and lymph nodes. The number of pulmonary metastases in animals on PC-SPES that showed no primary tumor growth had no metastatic lesions in the lung, however, in animals that did not respond to PC-SPES, the number of pulmonary metastases was not significantly different from the non-treated controls. The significant anti-tumor effects of PC-SPES on MAT-LyLu induced tumorigenesis and metastasis in Copenhagen rats, in general refractory to most conventional therapy, suggests a therapeutic benefit of this herbal food supplement and may be a useful adjuvant to conventional therapeutic modalities.

Selective responsiveness of human breast cancer cells to indole-3-carbinol, a chemopreventive agent

BACKGROUND

Indole-3-carbinol (I3C), a compound found in cabbage, broccoli, and brussels sprouts, inhibits the growth of mammary tumors when fed to certain strains of mice. The chemopreventive and antitumor effects of I3C depend on the species and tissue type. The mechanism of action and specific human cell types that respond to I3C are not known.

PURPOSE

Our purpose was to study the mechanism of action of I3C in estrogen-responsive (MCF-7) and estrogen-nonresponsive (MDA-MB-231) human breast cancer cell lines.

METHODS

Estrogen responsiveness was determined by the ability of estradiol to stimulate the growth of breast cancer cells deprived of estrogen. The effect of I3C was measured on cell growth, estradiol metabolism, and level of cytochrome P-4501A1. Growth was measured by cell counts and soft-agar assay, estrogen metabolism was examined by a radiometric assay, and the level of cytochrome P-4501A1 was measured by Western blots with a polyclonal antibody.

RESULTS

I3C inhibits the growth of estrogen-responsive cell line MCF-7 but has little effect on estrogen-nonresponsive cell line MDA-MB-231. Specific C-2 hydroxylation of estrogen and induction of cytochrome P-4501A1 was enhanced by I3C in the MCF-7 but not in the MDA-MB-231 cells.

CONCLUSION

I3C has specific antigrowth effects in human breast cancer cells. The inhibitory effects of I3C may involve selective induction of estradiol metabolism and the related cytochrome P-450 system that may be limited to estrogen-sensitive cells.

HER-2/neu amplification and overexpression in primary human breast cancer is associated with early metastasis

The etiology of human breast cancer is poorly understood and no specific marker of transformation has been identified. Amplification of HER-2/neu, as reported in a comprehensive study by Slamon et al, was found to be the most powerful predictor of disease-free and overall survival after the status of the axillary lymph nodes. Our study examines the HER-2/neu oncogene in 61 primary human breast cancers at both the DNA level (by Southern blotting) and the protein level (by immunohistochemical methods). Of the 61 tumors analyzed in our study, 17 (28%) had amplification of HER-2/neu. There was no significant correlation of HER-2/neu amplification with age, tumor diameter or hormone receptor status; however, amplification and overexpression of HER-2/neu was significantly correlated with the status of the axillary lymph nodes (P = 0.02). Of 16 patients with amplification of HER-2/neu, 14 (88%) had positive regional nodes. One of the two node negative cases with amplified HER-2/neu had bone marrow micrometastasis. Overall, 16 out of 17 (94%) tumors of the patients having amplified HER-2/neu had metastatic disease at the time of diagnosis. In summary, HER-2/neu amplification is associated with early tumor dissemination in primary human breast cancer and may be a marker of poor prognosis.

Augmentation of cytotoxicity using combinations of interferons (types I and II), tumor necrosis factor-alpha, and tamoxifen in MCF-7 cells

The cytotoxic effect of a combination of interferons (type I and II) and tumor necrosis factor (TNF), with an antiestrogenic drug, tamoxifen (TAM), was investigated in the estrogen receptor positive human breast carcinoma cell line, MCF-7. Cytotoxicity was measured by the MTT assay. In an attempt to define the molecular basis for the interaction between the interferons (IFNs) and TNF or any one of the cytokines with TAM, the induction characteristics of a number of IFN-induced mRNAs in response to IFNs, TNF, and TAM were studied. We observed an augmentation of the cytotoxic effect of TNF when it was combined with TAM. There appears to be an overlap in signalling mechanisms of IFNs and TNF as two of the IFN-inducible genes, 1-8 and 6-16 are also induced by TNF. mRNA 1-8 was induced by both IFN-alpha (type I) and IFN-gamma (type II). We conclude that TNF potentiates the cytotoxic effects of TAM in MCF-7 cells and that the three cytokines IFN-alpha, IFN-gamma, and TNF share some pathways that lead to specific induction of some cytokine responsive genes.

A distinct kinase modulates the expression of IFN-inducible genes in human breast cancer cells

The biological activity of interferons (IFNs) is presumed to be mediated through the induction of a number of IFN-inducible genes. IFN-mediated gene induction was examined in two human breast cancer cell lines, MCF-7 and BT-20. Both these cell lines were remarkably responsive to IFNs as a number of IFN inducible genes were rapidly induced. We examined the sensitivity of these genes towards 2-aminopurine (2-AP), a known inhibitor of double-stranded (ds) RNA dependent protein kinase. 2-AP has also been reported to inhibit the induction of IFN-beta 1 in response to dsRNA and the genes c-myc and c-fos in fibroblasts. In both MCF-7 and BT-20 cell lines, 2-AP selectively inhibited the IFN-induced gene responses. 2-AP did not affect levels of the oncogene, HER-2/neu. Tamoxifen (TAM), an antiestrogenic drug, which is known to inhibit the activity of protein kinase C at high concentrations, did not affect IFN-mediated gene induction. Our data is consistent with the concept that the 2-AP sensitive kinase is primarily associated with the IFN-induced gene systems and that positive and negative growth regulating stimuli in breast cancer may require the participation of distinct kinases.

Modulation of gene expression by selected fatty acids in human breast cancer cells

The effect of linoleic acid (LNA, n-6) and eicosopentanoic acid (EPA, n-3) was investigated on the parental MCF-7 cells and those transfected with v-H-ras. Transfection of v-H-ras oncogene renders the normally estrogen dependent MCF-7 cells estrogen independent. The effects of LNA and EPA in both the cell lines were measured by their ability to enhance the steady state cytoplasmic mRNA levels of 1-8 and 2-5 A, two genes whose transcription is enhanced in various cells in response to interferons (IFNs). The modulatory effect of these fatty acids on the level of an oncogene HER-2/neu was also investigated. Our results indicate that both the fatty acids induce mRNA 1-8 in parental MCF-7 cells but not in the ras transfected cell line, although the gene is induced in both cell lines in response to IFNs. mRNA 2-5A was not induced by LNA or EPA in either of the cell lines. HER-2/neu levels were enhanced by EPA in MCF-7-ras cells. Our data provide evidence to support the concept that selected, nutritionally relevant, fatty acids can regulate gene expression in vitro. These fatty acids can also induce second messenger signals similar to the ones generated by IFNs.

Influence of genotype on diet-induced changes in membrane phosphatidylcholine and phosphatidylethanolamine composition of splenocytes, liver nuclear envelope and liver mitochondria

Inbred congenic mice of strains MRL/Mp-lpr/lpr (lpr/lpr) and MRL/Mp(-)+/+ (+/+) were fed nutritionally adequate semipurified diets containing 20% (w/w) fat and differing in linoleic acid content. Levels of linoleic acid (18:2n-6) and arachidonic acid (20:4n-6) in phospholipids of splenocytes, liver mitochondria and liver nuclear envelopes were determined. Membranes of lpr/lpr mice exhibited significantly lower levels of 18:2n-6 and 20:4n-6 in phospholipids compared with the +/+ strain. The high linoleic acid diet increased incorporation of 18:2n-6 and 20:4n-6 in most phospholipid fractions of these membranes. These observations indicate that genotype as well as dietary 18:2n-6 content significantly influenced incorporation of 18:2n-6 and 20:4n-6 into membrane phospholipids. The results also suggest that membrane compositional abnormalities found in the lpr/lpr mice, which develop lymphoma and age faster than +/+ mice, are not restricted to the immune system but also extend to other organs. Differences observed in phospholipid fatty acid composition in splenocytes and liver subcellular membranes for mice fed diets differing in linoleic acid content suggest that the early expression of the lpr gene resulting in progression of autoimmunity may be delayed through dietary manipulation.

Interferon-alpha and gamma mediated gene responses in a human breast carcinoma cell line

Interferons (IFNs) have been known to possess an antiproliferative effect on tumor cells besides their well characterized antiviral effect in cell cultures. The mechanism of action of the different IFNs is not fully understood, but in recent years a number of IFN-inducible genes, the presumed mediators of IFN action, have been identified. In the present study we examined the antiproliferative effect of IFN-alpha and IFN-gamma on human breast cancer cells (MCF-7) using (i) the MTT dye formation assay and (ii) anchorage-independent (AI) growth in soft agar. Both IFN-alpha and IFN-gamma were found to have an antiproliferative effect on the growth of MCF-7 cells. In addition, the kinetics of induction of a number of IFN-inducible genes was also examined. The expression of these genes was measured by mRNA analyses using specific [alpha-32P]-labeled cDNAs as probes. The induction of these genes by IFN-alpha and IFN-gamma is a primary effect of IFN, as de novo protein synthesis is not required for their induction. Our results on the kinetics of induction of these genes by IFN-alpha and IFN-gamma suggests a complex mechanism of ligand-dependent gene activation in this cell line with some similar and dissimilar pathways.

Enhancement of expression of exogenous genes by 2-aminopurine. Regulation at the post-transcriptional level

In human and mouse cell lines, expression of exogenous genes was enhanced by treatment with 2-aminopurine (2-AP). Chloramphenicol acetyltransferase (CAT) and neomycin phosphotransferase activities were increased by up to 50-fold upon 2-AP treatment of cells permanently transfected with genes encoding these enzymes. Neomycin phosphotransferase activity was also increased by this treatment in cells infected with a retroviral vector carrying the neomycin phosphotransferase gene. 2-AP-mediated increase in CAT activity was observed in various cell lines which had been permanently transfected with chimeric CAT genes containing transcriptional regulatory elements of the interferon-inducible genes 6-16 and 561, SV40 early genes, mouse mammary tumor viral gene, or metallothionein II gene. The increase in the cellular CAT enzymatic activity was due to an elevated level of CAT protein. The 2-AP-mediated enhancement of CAT expression was operative at the translational level; the rate of transcription of CAT mRNA or its steady-state level was affected only marginally. The translational up-regulation by 2-AP was restricted to the genes introduced from outside; there was no gross change in the rate of synthesis of other cellular proteins.

Gene induction by interferons and double-stranded RNA: selective inhibition by 2-aminopurine

Transcription of several interferon-inducible human genes is also induced by double-stranded RNA. The nature and the mechanism of action of signals generated by interferons and by double-stranded RNA which mediate the induction of these genes are under investigation. Here we report that 2-aminopurine, a known inhibitor of protein kinases, could selectively block this induction process. Induction of mRNAs 561 and 6-16 in HeLaM cells by double-stranded RNA was completely inhibited by 10 mM 2-aminopurine, whereas cellular protein and RNA syntheses as well as the induction of metallothionein mRNA by CdCl2 were unaffected by this inhibitor. In addition, 2-aminopurine blocked the induction of the same two mRNAs and of mRNAs 2-5(A) synthetase, 2A, and 1-8 by alpha interferon and of mRNAs 2A and 1-8 by gamma interferon in HeLaM cells. The observed inhibition was at the level of transcription, and for establishing efficient inhibition, the 2-aminopurine treatment had to begin at early stages of interferon treatment. In GM2767 cells, 2-aminopurine inhibited induction of mRNAs 561 and 6-16 by double-stranded RNA but not by alpha interferon. These results suggest that double-stranded RNA-induced signal 2 is distinct from the interferon-alpha-induced signal 2 (R. K. Tiwari, J. Kusari, and G. C. Sen, EMBO J. 6:3373-3378, 1987) and that 2-aminopurine can block the former but not the latter. Moreover, it appeared that 2-aminopurine could block the production of signal 1 by interferons. This was confirmed by experiments in which we separately tested the effects of 2-aminopurine on signal 1 and signal 2 production by interferons in HeLaM cells. Although no direct experimental evidence is available as yet, our results are consistent with the hypothesis that the functioning of a protein kinase activity may be necessary for transcriptional induction of genes by double-stranded RNA and for gene induction by interferons in those cells in which signal 1 production is needed.

Influence of genotype on the phospholipid fatty acid composition of splenic T and B lymphocytes in MRL/MpJ-lpr/lpr mice

The MRL/MpJ-lpr/lpr mice manifest a T cell proliferative and autoimmune disorder. Similar changes occur much later in the life of MRL/MpJ-+/+ mice. MRL/MpJ-lpr/lpr (lpr/lpr) and MRL/MpJ-+/+ (+/+) mice were fed for six weeks nutritionally adequate semipurified diets containing 20% (w/w) fat, but differing in linoleic acid content. The phospholipid fatty acid composition of T and B cells was found to be dependent on genetic background of mice and level of linoleic acid in the diet. Changes in the levels of specific fatty acids like 16:0, 18:2 omega 6, 22:5 omega 3 and 22:6 omega 3 in some of the phospholipid components were observed in the MRL/MpJ-lpr/lpr strain in both the B and T cell types as compared with their normal +/+ counterpart strain. T cells of lpr/lpr mice exhibited significantly higher levels of 20:4 omega 6 than did T cells of other strain. High levels of dietary linoleic acid significantly increased incorporation of 18:2 omega 6 in T and B cells, while the effect on other fatty acids of the two types of cells varied with the phospholipid classes and fatty acids when compared with the low linoleic acid fed-group. Differences observed in the phospholipid fatty acid composition of the T and B cells of the congenic mice might contribute to differences in rate of progression of age-related changes suggesting that the autoimmune disorder might be mitigated by dietary manipulation.

Functional equivalents of interferon-mediated signals needed for induction of an mRNA can be generated by double-stranded RNA and growth factors

In our earlier studies we demonstrated that in HeLaM cells, interferon-alpha produces two functionally distinguishable signals, both of which are needed for induced transcription of mRNA 561 and other inducible mRNAs. Interferon-gamma cannot induce mRNA 561 because it produces only signal 1. Here we report that platelet-derived growth factor or epidermal growth factor could also produce signal 1. On the other hand, signal 2, which can be produced by interferon-alpha but not by interferon-gamma, could be elicited also by double-stranded RNA. Several lines of evidence suggest that the production of signal 2 by double-stranded RNA was not mediated through interferon. Interferon-induced transcription of mRNA 561 in HeLaM cells or in human fibroblast GM2767 cells was transient. However, in interferon-alpha-treated GM2767 cells, which had ceased to synthesize mRNA 561, transcription of this mRNA could be induced effectively by double-stranded RNA suggesting that this induction process could bypass the interferon-mediated down-regulation of induced transcription. Unlike HeLaM and GM2767 cells, in Daudi cells, induction of mRNA 561 by interferon-alpha was not transient. Transcription of this and two other induced mRNAs continued at a high rate even after 18 h of interferon-alpha treatment of these cells. The lack of down-regulation of interferon-induced gene expression may be responsible for interferon's acute antigrowth effects on these cells.

Clonal derivatives of the RD-114 cell line differ in their antiviral and gene-inducing responses to interferons

The human rhabdomyosarcoma cell line RD-114 is partially responsive to interferons (IFNs). In these cells, alpha interferon (IFN-alpha) or gamma interferon (IFN-gamma) inhibits the replication of some viruses but not of others. Similarly, some of the IFN-inducible mRNAs are induced poorly, whereas others are induced well. Here we report the isolation of clonal derivatives of this line which display different spectra of responses to IFNs. Among the eight extensively characterized clonal lines, one, C10, did not respond to IFN-alpha or IFN-gamma at all. Retrovirus production by each of the seven other lines was inhibited by both IFN-alpha and IFN-gamma. Replication of vesicular stomatitis virus was inhibited strongly by IFN-alpha in clone B1 but not in others, whereas it was not appreciably affected by IFN-gamma in any clone. Replication of encephalomyocarditis virus was inhibited strongly by IFN-gamma in clones A1, A2, A3, B3, and B8 and by IFN-alpha in clone A2. Neither IFN inhibited the multiplication of these clones greatly, although their doubling times were slightly increased. Five mRNAs were induced by IFNs to varying degrees in the seven clones. mRNA 2A was most strongly induced by IFN-gamma in clone A3. mRNA 1-8 was strongly induced by IFN-alpha in clone A1 and by either IFN in clones A2 and A3. The highest concentrations of 2',5'-oligoadenylate synthetase mRNA, mRNA 561, and mRNA 6-16 were in IFN-alpha-treated clones A1 and A2. These results demonstrated the existence of clonal heterogeneity in IFN responses in a cell line and strengthened the view that IFN treatment of cells generates multiple signals leading to a variety of IFN-induced phenotypes.

Expression of interferon-inducible genes in RD-114 cells

RD-114 is a cell line which is partially responsive to interferon (IFN). Although both IFN-alpha and IFN gamma inhibit production of the resident retrovirus, they do not inhibit replication of other viruses, such as vesicular stomatitis virus and encephalomyocarditis virus, in these cells. In the studies reported here, we studied the characteristics of induction of seven IFN-inducible mRNAs in RD-114 cells. We observed that mRNAs 561, 6-16, 1-8, 2A, and 6-26 have similar induction characteristics in RD-114 cells and in HeLa cells, a fully responsive line. mRNA 2'-5'-oligo-adenylate synthetase (2-5(A) synthetase), however, was induced more efficiently by IFN-alpha in HeLa cells than in RD-114 cells. The same was true for the induction of metallothionein II mRNA by IFN-gamma. However, the latter mRNA was induced equally strongly in both lines when ZnCl2 was used as the inducer, suggesting that the gene is not defective in RD-114 cells. Although IFN-alpha induced 2-5(A) synthetase mRNA poorly and IFN-gamma did not induce it at all in these cells, a mixture of IFN-alpha and IFN-gamma induced this mRNA quite effectively, to a level of induction comparable to that in HeLa cells. Only 1 U of IFN-gamma per ml was sufficient to elicit this synergism, and the data suggested that an IFN-gamma-inducible protein was needed for this process. Induction of mRNA 561 by IFN-alpha in RD-114 cells, unlike that in HeLa cells, did not need ongoing protein synthesis. Once induced, this mRNA turned over rapidly in both cell lines, and this turnover could be slowed down by inhibiting protein synthesis in either cell line. IFN-induced mRNAs, such as 561 and 1-8, were polysome associated in IFN-treated RD-114 cells, suggesting that they were actively translated. Therefore, it is unlikely that the products of these IFN-inducible genes, by themselves, mediate the inhibition of replication of those viruses which are insensitive to IFN action in RD-114 cells.

Effects of L-ascorbic acid supplementation on dieldrin toxicity in rats

Chronic dieldrin administration to rats (5 mg/kg/day) produced pathological changes in liver and kidney tissues. Dieldrin treated rats showed high levels of liver ascorbic acid and increased activities of inorganic pyrophosphatase in brain and glucose-6-phosphatase in liver. The activities of Mg2+-ATPase in liver and acetylcholinesterase in brain were decreased under toxic doses of dieldrin. L-Ascorbic acid supplements in treated animals could partially prevent the pathological alterations, as observed histologically in liver and kidney tissues. Administration of this vitamin could also prevent alterations in some enzyme activities produced by toxic dieldrin doses.

Effect of dieldrin on rat liver plasma membrane enzymes

Dieldrin, an organochlorine insecticide, when administered orally to male albino rats at a dose of 5 mg/kg body weight/day for 15 days inhibits the enzyme Mg2+ -ATPase and stimulates the activity of 5'-nucleotidase and NADH-dehydrogenase in liver plasma membrane. L-ascorbic acid supplementation offers some protection in relation to the inhibition of Mg2+ -ATPase.