Pneumatic elastostatics of multi-functional inflatable lattices: realization of extreme specific stiffness with active modulation and deployability

As a consequence of intense investigation on possible topologies of periodic lattices, the limit of specific elastic moduli that can be achieved solely through unit cell-level geometries in artificially engineered lattice-based materials has reached a point of saturation. There exists a robust rationale to involve more elementary-level mechanics for pushing such boundaries further to develop extreme lightweight multi-functional materials with adequate stiffness. We propose a novel class of inflatable lattice materials where the global-level stiffness can be derived based on a fundamentally different mechanics compared with conventional lattices having beam-like solid members, leading to extreme specific stiffness due to the presence of air in most of the lattice volume. Furthermore, such inflatable lattices would add multi-functionality in terms of on-demand performances such as compact storing, portability and deployment along with active stiffness modulation as a function of air pressure. We have developed an efficient unit cell-based analytical approach therein to characterize the effective elastic properties including the effect of non-rigid joints. The proposed inflatable lattices would open new frontiers in engineered materials and structures that will find critical applications in a range of technologically demanding industries such as aircraft structures, defence, soft robotics, space technologies, biomedical and various other mechanical systems.

Size-dependent dynamic characteristics of graphene based multi-layer nano hetero-structures

Carbon-based nano hetero-structures are receiving increasing attention due their ability in multi-synchronous modulation of a range of mechanical and other critically desirable properties. In this paper, the vibration characteristics of two different graphene based heterostructures, graphene-hexagonal boron nitride (hBN) and graphene-molybdenum disulfide (MoS₂), are explored based on atomistic finite element approach. Such vibrational characteristics of nanostructures are of utmost importance in order to access their suitability as structural members for adoption in various nano-scale devices and systems. In the current analysis, the developed atomistic finite element model for nano-heterostructures is extensively validated first with the results available in literature considering elastic responses and natural frequencies. Thereafter a range of insightful new results are presented for the dynamic behaviour of various configurations of graphene-hBN and graphene-MoS₂ heterostructures including their size, chirality and boundary dependence. The investigation of tunable vibrational properties along with simultaneous modulation of other mechanical, electronic, optical, thermal and chemical attributes of such nano-heterostructures would accelerate their application as prospective candidates for manufacturing nanosensors, electromechanical resonators, and a wide range of other devices and systems across the length-scales.

Probing the shear modulus of two-dimensional multiplanar nanostructures and heterostructures

Generalized high-fidelity closed-form formulae have been developed to predict the shear modulus of hexagonal graphene-like monolayer nanostructures and nano-heterostructures based on a physically insightful analytical approach. Hexagonal nano-structural forms (top view) are common for nanomaterials with monoplanar (such as graphene and hBN) and multiplanar (such as stanene and MoS₂) configurations. However, a single-layer nanomaterial may not possess a particular property adequately, or multiple desired properties simultaneously. Recently, a new trend has emerged to develop nano-heterostructures by assembling multiple monolayers of different nanostructures to achieve various tunable desired properties simultaneously. Shear modulus assumes an important role in characterizing the applicability of different two-dimensional nanomaterials and heterostructures in various nanoelectromechanical systems such as determining the resonance frequency of vibration modes involving torsion, wrinkling and rippling behavior of two-dimensional materials. We have developed mechanics-based closed-form formulae for the shear modulus of monolayer nanostructures and multi-layer nano-heterostructures. New results of shear modulus are presented for different classes of nanostructures (graphene, hBN, stanene and MoS₂) and nano-heterostructures (graphene-hBN, graphene-MoS₂, graphene-stanene and stanene-MoS₂), which are categorized on the basis of fundamental structural configurations. The numerical values of shear modulus are compared with the results from the scientific literature (as available) and separate molecular dynamics simulations, wherein a good agreement is noticed. The proposed analytical expressions will enable the scientific community to efficiently evaluate shear modulus of a wide range of nanostructures and nanoheterostructures.

Effective mechanical properties of multilayer nano-heterostructures

Two-dimensional and quasi-two-dimensional materials are important nanostructures because of their exciting electronic, optical, thermal, chemical and mechanical properties. However, a single-layer nanomaterial may not possess a particular property adequately, or multiple desired properties simultaneously. Recently a new trend has emerged to develop nano-heterostructures by assembling multiple monolayers of different nanostructures to achieve various tunable desired properties simultaneously. For example, transition metal dichalcogenides such as MoS₂ show promising electronic and piezoelectric properties, but their low mechanical strength is a constraint for practical applications. This barrier can be mitigated by considering graphene-MoS₂ heterostructure, as graphene possesses strong mechanical properties. We have developed efficient closed-form expressions for the equivalent elastic properties of such multi-layer hexagonal nano-hetrostructures. Based on these physics-based analytical formulae, mechanical properties are investigated for different heterostructures such as graphene-MoS₂, graphene-hBN, graphene-stanene and stanene-MoS₂. The proposed formulae will enable efficient characterization of mechanical properties in developing a wide range of application-specific nano-heterostructures.

Self-preserving personal care products

OBJECTIVE

As questions on the safety of some popular preservatives are on the rise, there is a growing interest in developing 'self-preserving' personal care products. Use of multifunctional ingredients/actives with antimicrobial properties has been explored as replacements for conventional preservatives. This study explores the use of combinations of multifunctional actives (MFA) and other cosmetic ingredients in various personal care formulations, to deliver microbiologically safe self-preserving products. Products studied in this study include face wash, gel-based leave-on skin care product and face mask.

METHODS

Minimum inhibitory concentration (MIC) of several cosmetic ingredients was determined to identify multifunctional actives with antimicrobial activity. Personal care formulations made with multifunctional actives and other cosmetic ingredients were studied for preservative efficacy by challenging the product with six multiple cycles of microbial challenge.

RESULTS

Formulations with combinations of multifunctional actives with antioxidant (AO) and chelators (CHL) were found to work synergistically and were highly efficacious in controlling multiple microbial challenges as observed in the preservative efficacy test (PET) studies. The effective combinations were able to withstand up to six multiple microbial challenges without product degradation. The preservative efficacy profile was similar to control formula containing preservatives.

CONCLUSION

Self-preserving personal care/cosmetic products can be developed which are as efficacious as preserved products by a prudent selection of multifunctional actives, antioxidants and chelators as a part of the formulation.

Use of Iron Chelating Agents in Transfusion Dependent Thalassaemia Major Patients

This cross-sectional study was done to find and investigate the utilization pattern of iron chelating agents among 73 transfusion-dependent thalassaemia major patients with continuous enrolment for at least 1 year in a day care treatment centre run by The Thalassaemia Society of India, Kolkata from November 2014 to January 2015. Transfusion dependent thalassaemia major patients above the age of 2 years managed by various haematologists and Thalassaemia specialists were studied. The administration of iron chelators namely Desferrioxamine (DFO), Deferiprone (DFP) and Deferasirox (DFX) were evaluated. Forty seven (64%) of the thalassaemics had serum ferritin level below 2500 ng/dl, of whom 20(27%) patients have ferritin level below 1000ng/dl. A number of 55(75%) of 73 patients who were treated with a single chelating agent consisted 50 patients only on DFX. Exact 8(67%) patients were on DFO+DFP and 4(33%) are treated with DFX+DFP. The mean age was 19 and mean serum ferritin level was 2280 ng/dl among the thalassaemia major patients. DFX was used 68% of patients as monotherapy and 5% patients in combination therapy with DFP. DFX in the dose of 30-40 mg/kg/day was prescribed in 52% of patients. Mean dose of 15 mg/kg/day of DFX was been administered in combination with DFP (75 mg/kg/day) in 5% patients. DFO+DFP were preferred by 8 patients, out of which 6 were aged above 25. Cost of monotherapy is twice that of combination therapy. These data demonstrates the ferritin status and present scenario of utilization of chelating agents among thalassaemia major patients on repeated transfusions. The dosing of new drug, Deferasirox and the cost analysis of various chelating regimen has also been dealt. Individualization rather than rationalization of chelation therapy should be focussed upon in managing iron overload in thalassaemia.

Chemical constituents and biological studies of Origanum vulgare Linn

Bioassay-guided isolation of methanolic extract of the leaves of Origanum vulgare Linn., yielded two protocatechuic acid ester derivatives, origanol A (1) and origanol B (2) along with ursolic acid (3), oleanolic acid (4), β-sitosterol (5), and triacontanol (6). Structures of the compound were established based on physical and spectral data (UV, IR, ¹H and ¹³C NMR and mass). Origanol A (1) showed significant mushroom tyrosinase inhibition activity.

Dandruff: the most commercially exploited skin disease

The article discuss in detail about the prevalence, pathophysiology, clinical manifestations of dandruff including the etio-pathology. The article also discusses in detail about various treatment methods available for dandruff. The status of dandruff being amphibious – a disease/disorder, and relatively less medical intervention is sought after for the treatment, dandruff is the most commercially exploited skin and scalp disorder/disease by personal care industries.

Can increasing the dose of radiation by HDR brachytherapy boost following pre operative chemoradiotherapy for advanced rectal cancer improve surgical outcomes?

AIM

Preoperative radiotherapy has been shown to improve local control in advanced rectal carcinoma compared with surgery alone. Several large randomized trials have confirmed that chemoradiotherapy (CRT) is better than radiotherapy alone. This pilot study was designed to increase the radiation dose using high-dose rate (HDR) brachytherapy boost following preoperative CRT to evaluate whether this strategy improves the outcome of surgery without increase in toxicity.

METHOD

Since October 2004, we have used the new rectal HDR applicator for brachytherapy boost in 68 patients following CRT. The patients had CT and MRI Scans as part of staging. All had locally advanced disease either bulky low T2 or T3 with threatened circumferential resection margin and multiple suspicious lymph nodes. They were offered preoperative CRT either by 5-FU infusion 1 g/m(2) day 1-4 (week 1 + 5) or by oral capecitabine 825 mg/m(2) Monday-Friday for 5 weeks together with CT planned external beam RT 45Gy in 25 fractions over 5 weeks (CRT). Those downstage on repeat MRI scan were offered additional HDR Boost 10Gy directly to the tumour followed by surgery 6-8 weeks later [group A]. Four patients proceeded directly to surgery but because of involved resection margin had a HDR brachytherapy boost as postoperative treatment [group B]. Thirty patients were not planned for immediate surgery after CRT and brachytherapy boost, as they were either elderly or considered high risk for anaesthesia [group C].

RESULTS

There were 34 patients (median age 67 (range 39-81) years in group A, including 24 men). The PS was 0-1. The clinical stage at presentation was cT2 in five, cT3 in 23 and T4 in six patients and cN0 in 2, cN1 in 21 and N2 in 11. Thirty-three patients had CRT, and one had radiotherapy alone. All patients completed treatment without interruption. Twenty-nine patients had surgery following CRT and brachytherapy boost including anterior resection in 10 patients, Abdominoperineal excision (APR) in 18 and Hartmann's resection in one. Five patients did not have the intended surgery. Twenty-four (83%) patients had an RO resection compared with 63% having conventional preoperative CRT using bolus 5FU regimes. Pathological complete remission (pCR) was achieved in 9 (31%) compared with 12% patients having conventional CRT. There was no increase in G 3-4 toxicity from RT and no delay in wound healing or increase in anastomotic leakage. One of the four patients in group B developed local recurrence. The thirty patients in group C who had modified radical CRT followed by brachytherapy boost as a definitive treatment will be reported in a further communication.

CONCLUSION

Increasing the dose of radiation by HDR brachytherapy boost appears to improve the RO resection and pCR rates compared with conventional CRT. The follow up is too short to judge its effect on disease-free survival. This study will be extended to compare this strategy in a randomized phase III trial with conventional CRT in patients who are not fit for more intensive CRT (HERCULES).

Two-dimensional gel analysis of apoptosis-specific p53 isoforms induced by 2-methoxyestradiol in human lung cancer cells

The natural metabolic byproduct of estradiol, 2-methoxyestradiol (2-MeOE2), induces apoptosis in human lung cancer cells by a p53-dependent mechanism. The expression of wild-type p53 isoforms was investigated in H1299 non-small cell lung carcinoma cells induced into apoptosis by 2-MeOE2. H1299 cells lack endogenous p53 and undergo predominantly a G1 arrest when infected with a recombinant wild-type p53 adenovirus. However, when H1299 cells transfected with p53 were treated with 2-MeOE2, they underwent rapid and extensive apoptosis. H1299 cells expressing mutant his273 p53 were unaffected by 2-MeOE2, indicating a dependence of 2-MeOE2-mediated apoptosis on the presence of a functional p53. Analysis of wild-type p53 phosphoisoforms in H1299 cells by two-dimensional gel electrophoresis revealed that 2-MeOE2 induced a unique group of acidic p53 isoforms. Although most of the wild-type p53 in untreated H1299 cells migrated as at least five diffuse species with isoelectric points from pH 5.5-6.3, as many as nine additional forms migrating toward the acidic region with pI values from 4.4-5.3 were detected in 2-MeOE2-treated apoptotic cells. Two other agents known to induce apoptosis, vinblastine and actinomycin D, induced a similar pattern of acidic p53 species as that observed for 2-MeOE2. The results indicated that the induction of apoptosis in H1299 cells by 2-MeOE2 is dependent on the upregulation of specific p53 isoforms. Identification of the specific p53 phosphoisoforms induced by MeOE2 will be an important step in understanding the regulation and function of p53 in apoptosis.

Evaluation of serum mucoproteins in patients suffering from liver cancers

Mucoproteins are normal and essential constituents of different types of cells, tissues, and organs in our body. Interestingly, an increase in the serum mucoprotein has been described in several malignant disorders in various studies. To study this in the cases of hepatocellular carcinoma thirty five patients suffering from histologically or cytologically confirmed hepatocellular carcinoma were tested for serum mucoprotein in the Department of Biochemistry and the Department of Pathology of North Bengal Medical College for a period of one and a half years against matched healthy controls. The serum mucoprotein was found to be increased significantly in the cases suffering from hepatocellular carcinoma (p<0.001). So, the present study suggests a strong correlation between the mucoprotein level and carcinomatous changes in the hepatocellular tissues.

Prevalence of criminal offending by men and women with intellectual disability and the characteristics of offenders: implications for research and service development

The investigation of the relationship between criminal offending and the presence of an intellectual disability (ID) is problematic for two main reasons. First, because of problems associated with the definition of 'ID' and secondly, because much criminal offending goes undetected or unreported, and studies can only investigate those already involved with the criminal justice process. Studies using IQ as a continuous variable indicate that significantly below-average intellectual ability is an independent predictor of future offending. Whilst people with ID may be over-represented in parts of the criminal justice system, given the intellectual and other psychosocial disadvantages which they experience, the level of offending behaviour in this particularly vulnerable group is strikingly low. The present authors propose that two broad groups of people can be identified. The first, broader, group is one of people for whom social disadvantage and mental ill health (particularly substance abuse), coupled with a significant intellectual impairment, are the main characteristics. Secondly, there is a smaller group of people, usually already known to ID services as service users, but for whom the process whereby what might have been conceptualized as 'challenging behaviour' becomes 'offending' is far from clear. The distinction the present authors make between challenging behaviour and offending is important for understanding how 'difficult' behaviour becomes identified as 'antisocial/criminal behaviour'. They argue that research needs to move from prevalence and descriptive studies to investigating the processes which determine movement in and out the criminal justice system. The present political emphasis on public protection and proposals for significantly broader mental health legislation raise the danger of a re-expansion of institutional models of care, rather than the development of multi-agency support networks. The present paper underscores a note of caution, particularly where choices have to be made between expanding institutional models on the one hand and providing more integrated services on the other. Over and above policy decisions, these are social and political choices.

Multiple lysine mutations in the C-terminal domain of p53 interfere with MDM2-dependent protein degradation and ubiquitination

To investigate the effect of mutations in the p53 C-terminal domain on MDM2-mediated degradation, we introduced single and multiple point mutations into a human p53 cDNA at four putative acetylation sites (amino acid residues 372, 373, 381, and 382). Substitution of all four lysine residues by alanines (the A4 mutant) and single lysine-to-alanine substitutions were functional in sequence-specific DNA binding and transactivation; however, the A4 mutant protein was resistant to MDM2-mediated degradation, whereas the single lysine substitutions were not. Although the A4 mutant protein and the single lysine substitutions both bound MDM2 reasonably well, the single lysine substitutions underwent normal MDM2-dependent ubiquitination, whereas the A4 protein was inefficiently ubiquitinated. In addition, the A4 mutant protein was found in the cytoplasm as well as in the nucleus of a subpopulation of cells, unlike wild-type p53, which is mostly nuclear. The partially cytoplasmic distribution of A4 mutant protein was not due to a defect in nuclear import because inhibition of nuclear export by leptomycin B resulted in nuclear accumulation of the protein. Taken together, the data suggest that mutations in the putative acetylation sites of the p53 C-terminal domain interfere with ubiquitination, thereby regulating p53 degradation.

Oral administration of an estrogen metabolite-induced potentiation of radiation antitumor effects in presence of wild-type p53 in non-small-cell lung cancer

PURPOSE

The purpose of this study was to investigate the efficacy of 2-methoxyestradiol as an antitumor and radiosensitizing agent for the treatment of human malignancy.

METHODS AND MATERIALS

Two cancer cell lines with wild-type p53 status were exposed first to irradiation and then to an oral formulation of the nontoxic metabolite 2-methoxyestradiol (2ME) to stabilize p53 levels.

RESULTS

Cell growth was inhibited via G1 growth and apoptosis. Subsequent in vitro growth and Tunel assays indicated that this combination was superior to radiation alone at inducing p53 protein accumulation, stabilizing p53 protein levels, and substantially reducing long-term tumor cell growth (approximately 80%) and colony formation (approximately 95%) in vitro, and inducing apoptosis. However, harboring mutated p53, H322 cell line, was relatively insensitive to such a treatment regimen. Western blot analysis revealed that growth inhibition was associated with increased levels of p53 and p21 protein accumulation. Experiments with subcutaneous tumor in a nu/nu mouse showed the combination treatment to be superior to radiation alone at reducing tumor growth ( approximately 50% reduction as compared to radiation alone) in vivo.

CONCLUSION

Thus, our studies confirmed a unique strategy whereby oral administration of a nontoxic estrogen metabolite, 2ME, significantly enhanced the radiation effect on a subcutaneous tumor without any toxicity and suggesting that this strategy may be clinically useful as an adjuvant therapy.

Cellular and humoral immune responses to adenovirus and p53 protein antigens in patients following intratumoral injection of an adenovirus vector expressing wild-type. P53 (Ad-p53)

The immune responses of 10 patients with advanced non-small cell lung cancer receiving monthly intratumoral injections of a recombinant adenovirus containing human wild-type p53 (Ad-p53) to adenovirus and transgene antigens were studied. The predominate cellular and humoral immune responses as measured by lymphocyte proliferation and neutralizing antibody (Ab) formation were to adenovirus serotype 5 vector antigens, with increased responses in posttreatment samples. Consistent alterations in posttreatment cellular and humoral immune responses to p53 epitopes were not observed, and cytotoxic Abs to human lung cancer cells were not generated. Patients in this study had evidence of an antitumoral effect of this treatment with prolonged tumor stability or regression; however, neither Abs to p53 protein nor increased lymphocyte proliferative responses to wild-type or mutant p53 peptides have been consistently detected.

Methylsulfomycin I, a new cyclic peptide antibiotic from a Streptomyces sp. HIL Y-9420704

Methylsulfomycin I (1) is a new cyclic peptide antibiotic isolated from the fermentation broth of a Streptomyces sp. HIL Y-9420704. Its structure was elucidated by NMR and GC-MS. The in vitro activity (MIC) against a wide range of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-, and teicoplanin-resistant strains, is described.

Coherent stochastic resonance in the case of two absorbing boundaries

The coherent stochastic resonance is observed and studied with a multistep periodic signal in a continuous medium having two absorbing boundaries. The general features of this process are exhibited. The universal features at the resonance point are demonstrated. The kinetic behaviors around the resonance point are also presented.

Mathemycin B, a new antifungal macrolactone from actinomycete species HIL Y-8620959

A new macrocyclic lactone antibiotic mathemycin B (1) was isolated from the fermentation broth of an Actinomycete sp. culture Y-8620959. The structure of 1 was elucidated by high-resolution MS and interpretation of 2D NMR results. Mathemycin B is active against a variety of phytopathogenic organisms.

Potent antitumor activity of 2-methoxyestradiol in human pancreatic cancer cell lines

We examined the effect of 2-methoxyestradiol (2-ME) on the growth and tumorigenesis of human pancreatic cancer cells. 2-ME inhibited the growth of these cell lines (50-90%) in a dose- and time-dependent fashion, and terminal deoxynucleotidyl transferase staining showed that it induced apoptotic cell death. Flow cytometric analysis indicated that 2-ME-sensitive cells showed a prolonged S phase after 48 h of treatment. We used a mouse model for in vivo studies of lung metastasis and injected MIA PaCa-2 cells into the tail veins of nu/nu mice; lung colonies were formed. Mice given oral 2-ME showed 60% inhibition in the number of lung colonies compared with control, untreated animals. These results suggest that 2-ME may have clinical application for the treatment of pancreatic cancer.

An agent that increases tumor suppressor transgene product coupled with systemic transgene delivery inhibits growth of metastatic lung cancer in vivo

Low levels of gene expression following systemic delivery have impaired the effectiveness of tumor suppressor gene replacement in treating metastases. We asked whether combined treatment with 2-methoxyestradiol (2-Me), which increases levels of wild-type p53 protein in cancer cells, and the systemic administration of an adenoviral vector expressing wild-type p53 (Ad-p53) would inhibit the growth of human metastatic lung cancer cells in vivo. The simultaneous administration of p53 and 2-Me resulted in a greater than additive reduction with the lung colony count reduced to 33% of its control value. These results suggest that the synergistic effect of 2-Me and Ad-p53 in combination treatment may have application in the systemic treatment of cancer.

Reduced telomeric signals and increased telomeric associations in human lung cancer cell lines undergoing p53-mediated apoptosis

Transduction of a p53-negative H1299 human non-small cell lung cancer cell line with an adenoviral vector containing wild-type p53 (Ad5p53) induced apoptosis. Analysis of the Ad5p53-infected H1299 cells showed high levels of telomeric association prior to apoptotic nuclear fragmentation. Similar telomeric association was observed in stably transfected clones of the wtH226b cell line, which expressed exogenous wild-type p53 protein and also showed complex chromosomal abnormalities including dicentrics, rings and fragments. Fluorescence in situ hybridization (FISH) analysis using a human telomeric DNA probe indicated reductions in telomere signals in both Ad5p53-infected H1299 cells and wtH226b-S cells. In contrast, stably transfected wtH226b-AS clones expressing antisense p53 cDNA showed no telomeric association and had high levels of telomeric signals associated with a faster growing phenotype. These results suggest that wild-type p53 is involved in shortening telomeres, a possibly early event in the p53-mediated apoptotic process and in the subsequent telomeric association that predisposes a cell to genetic instability and DNA fragmentation resulting in apoptotic cell death. Moreover, loss of telomeric signals may indicate a cell's decision to undergo programmed cell death and, if so, could, serve as a sensitive marker of p53-mediated apoptosis.

Superinduction of wild-type p53 protein after 2-methoxyestradiol treatment of Ad5p53-transduced cells induces tumor cell apoptosis

Because 2-methoxyestradiol (2-MeOE2) induces and stabilizes wild-type p53 protein (wt p53) in human lung cancer cell lines posttranscriptionally, we sought to study its effects on Ad5p53-transduced lung cancer cell lines at a low multiplicity of infection (1 MOI). Treating these cells with 2-MeOE2 resulted in superinduction of wt p53 protein expression followed by apoptosis, as shown by terminal deoxynucleotidyl transferase (TdT) staining, and upregulation of wt p53 expression, as shown by Western blot analysis. When transduced with Ad5p53 alone at 1 MOI, the cell lines grew rapidly. Moreover, adenoviral-vector-mediated p53 gene transfer followed by 2-MeOE2 treatment caused 80% growth inhibition in the cell lines regardless of their p53 status. Thus, p53 superinduction and apoptosis after 2-MeOE2 treatment in Ad5p53-transduced cells appears to be a unique strategy with significant implications for cancer gene therapy.

[2-methoxyestradiol induces p53 independent apoptosis in pancratic carcinoma and inhibits growth of lung metastasis]

2-methoxyestradiol (2-ME) is able to inhibit growth of certain tumors. We were interested in studying this effect of 2-ME on pancreatic cancer. In three out of four cell lines, 2-ME induced 50-90% growth inhibition after 48 hours treatment with 2 microM 2-ME. TUNEL staining for apoptosis revealed that after treatment with 2 microM 2-ME for 48 hours 37-97% of these cells underwent apoptotic cell death (p < 0.005-0.0001). Since all cell lines used harbor a p53 mutation, this apoptosis appears to be p53 independent. One of these cell lines (MIAPaCa-2) was used for the in vivo experiment in nude mice. After a daily oral administration of 1 mg 2-ME for three weeks, the number of lung metastases could be reduced by 59%, as compared to the control non treated group (p < 0.0005). No signs of toxicity were seen. It appears that 2-ME is a potent compound for the treatment of pancreatic cancer, which might be interesting for clinical application.

Induction of apoptosis in human lung cancer cells after wild-type p53 activation by methoxyestradiol

2-Methoxyestradiol (2-MeOE2) treatment caused significant growth inhibition of H460 and A549 human lung cancer cell lines which contain wild-type p53. However, 2-MeOE2 had a little effect on the p53 negative H358 and p53 mutated H322 cell lines. Western blot analysis indicated that 2-MeOE2 treatment resulted in an eightfold increase in the endogenous wild-type p53 protein, while the level of the mutant p53 protein remained unchanged. TdT staining indicated that following 2-MeOE2-mediated increases in wildtype p53 protein, cells bypass the G1-S checkpoint of the cell cycle with 30 to 40% undergoing apoptosis. Introduction of anti-sense wt-p53 into wt-p53 cells abrogated the 2-MeOE2 effect. A significant portion of lung cancer retains the wild-type p53 gene therefore, 2-MeOE2 may have therapeutic application.

Analysis of phosphorylated isoforms of the p53 tumor suppressor protein in human lung carcinoma cells undergoing apoptosis

The expression of p53 tumor suppressor protein isoforms in H460a cells induced to undergo apoptosis by 2-methoxyestradiol was investigated by two-dimensional gel electrophoresis. Whole-cell proteins from control and apoptotic H460a cells were separated by two-dimensional electrophoresis and were transferred to nitrocellulose. The p53 isoforms were detected by immunoblotting using p53 monoclonal antibody Bp53-12. Four isoforms of p53 (2, 3, 5, and 6) differing in phosphorylation state were detected in control cells. Three additional isoforms (1, 4, and 7) were observed to be expressed at significant levels only in apoptotic cells. The differential expression of isoforms 1, 4, and 7 in apoptotic cells suggests that one or more specific phosphorylation events generating these forms of p53 could play a role in regulating the function of p53 in apoptosis.

Induction of p53 DNA-binding activity by tumor necrosis factor-alpha

Tumor necrosis factor-alpha (TNF-alpha) has been reported to activate the murine p53 promoter, which was mediated by activation and binding of the NF-kappa B transcription factor to the intact p53 consensus binding site. We show in this report that TNF-alpha at concentrations of 0.1 nM induced the DNA-binding activity of wild-type p53 fivefold in the H460a human lung carcinoma cell line. The increases in p53 DNA-binding activity by TNF-alpha in H460a cells resulted from a post-translational activation mechanism, since levels of the p53 protein remained unchanged in TNF-alpha-treated cells. Furthermore, Northern and nuclear run-off analyses ruled out an increase in transcriptional activity of the promoter of the human p53 gene in TNF-alpha-treated cells. These results are in contrast to those reported for the murine p53 gene, whose promoter is induced by TNF-alpha through activation of the NF-kappa B transcription factor. To determine the molecular basis for the lack of activation of the human p53 gene promoter by TNF-alpha, the binding of NF-kappa B to the kappa B-like sites in the murine and human p53 promoters was compared in nuclei of TNF-alpha-treated NSCLC cells by electrophoretic mobility shift assay. The human kappa B-like site differs from the murine by the substitution of two base pairs. With the exception of the H460a cell line, all NSCLC cell lines treated with 0.1 nM concentrations of TNF-alpha exhibited increased NF-kappa B DNA-binding activity. The kappa B-like site located in the murine p53 promoter bound strongly to NF-kappa B complexes in p53-negative H1299 cells. However, the kappa B-related site in the human p53 promoter showed a much lower affinity for NF-kappa B complexes. In addition, p50 homodimers specifically interacted with the human kappa B site, whereas p65/p50 heterodimers bound selectively to the mouse kappa B site. We conclude that TNF-alpha can activate human wild-type p53 in NSCLC cells by a post-translational mechanism. Moreover, the inability of TNF-alpha to activate the human p53 gene promoter, in contrast to that reported for the murine p53 gene, may be the result of differences in the interactions of the murine and human kappa B sites with NF-kappa B complexes.

Retrovirus-mediated wild-type p53 gene transfer to tumors of patients with lung cancer

A retroviral vector containing the wild-type p53 gene under control of a beta-actin promoter was produced to mediate transfer of wild-type p53 into human non-small cell lung cancers by direct injection. Nine patients whose conventional treatments failed were entered into the study. No clinically significant vector-related toxic effects were noted up to five months after treatment. In situ hybridization and DNA polymerase chain reaction showed vector-p53 sequences in posttreatment biopsies. Apoptosis (programmed cell death) was more frequent in posttreatment biopsies than in pretreatment biopsies. Tumor regression was noted in three patients, and tumor growth stabilized in three other patients.

WAF1 expression is independent of p53 gene alterations and protein expression in human lung cancer cells

Accumulation of wild-type p53 protein arrests cells primarily at G(1)-S. This arrest is characterized by accumulation of the cyclin-dependent kinase inhibitor p21 (WAF1/CIP1) protein. Since the WAF1 gene is itself a target of p53, we investigated p53 gene expression to understand the mechanism 3 of p21 regulation in cellular transformation in human non-small cell lung cancer lines and tumor tissues. Northern and Western blot analyses in cell lines carrying wild-type or mutated p53 showed that WAFI mRNA and protein expression varied among different cell lines. WAFI expression was not directly correlated with the p53 status of the cells. WAFI was also expressed at high levels in the absence of p53 expression in a p53-deleted cell line (H358). Abrogation of p53 protein in H226b (wild-type p53) and H322 (mutated p53) cell lines by antisense RNA reduced WAFI expression in both lines, indicating that mutations in the p53 gene may not necessarily abrogate p53-mediated regulation of WAFI expression. Fourteen primary lung tumors were analyzed for p53 status by SSCP analysis and DNA sequencing. Eight of 14 lung tumor tissues examined contained p53 mutations. Six of 14 contained wildtype p53. Enhanced p21 expression was detected in two lung tumors containing p53 mutations by immunohistochemistry. Together, these data indicate that WAFI expression is independent of p53 gene alterations and protein expression in non-small cell lung tumor cells.

Growth inhibitory effect of anti-K-ras adenovirus on lung cancer cells

An adenoviral vector carrying a 2-Kb fragment of the K-ras proto-oncogene inserted in antisense orientation with respect to the cytomegalovirus promoter was constructed and used to infect H460a lung cancer cells (codon 61 K-ras mutation). The gene was efficiently transferred, and a high level of expression of antisense K-ras was achieved. At a multiplicity of infection to achieve 65% transduction of cells, the expression of K-ras protein was reduced by 70% in the lung cancer cell line H460a as compared with cells infected with control vectors or noninfected cells. This reduction produced a 47% inhibition of monolayer growth and a 90% inhibition of colony formation. At a similar level of transduction in the cell line H358 (codon 12 K-ras mutation), a 59% inhibition of monolayer growth compared with control vectors occurred; however the inhibition of H322 cells (wild-type k-ras) growth was no different than control vector infected cells. These data suggest that the adenoviral K-ras H322a antisense vector may have therapeutic potential in tumors in which K-ras is mutated.

Functional inactivation of p53 by antisense RNA induces invasive ability of lung carcinoma cells and downregulates cytokeratin synthesis

Previously we had identified a p53 DNA-binding motif in the 5' region of the CK8 gene This finding led us to study the role of p53 protein in the regulation of CK8 gene expression and its role in tumorigenesis. Human lung cancer cell lines stably transfected with antisense p53 cDNA that expressed little p53 protein were analyzed. CK8 mRNA and the protein expression in these p53 antisense clones were very low as revealed by northern and western blot analysis. Immunofluorescence studies indicated that the cytokeratin networks around the nuclei of these cells collapsed; although some staining was observed around the nuclei. Antisense clones were highly invasive on in vitro matrigel assay. Scanning electron microscopy of the surface topography of these antisense clones revealed a large number of microvilli on their surfaces, a phenotype characteristic of tumor cell invasion. These findings suggest that functional inactivation p53 protein could be an important step in tumor progression.

Antisense regulation of oncogenes in human cancer

Gene transfer or manipulation of genes for the treatment of cancer is a rapidly expanding field. In recent years, much attention has been focused on manipulating cancer genes and applying antisense technology in therapeutic ways. Consequently, antisense RNA control is now recognized as a specific means of regulating gene expression at the posttranscriptional level. Defects in vital genes occur in many human diseases, including cancer, defects that may be due to an accumulation of mutations in the genes that leads to the production of faulty proteins. Although the biological significance of such mutant proteins still remains in question, recent experiments have demonstrated that genes overproducing faulty proteins are often associated with increased tumor cell growth. Moreover, using a stretch of antisense RNA to block the production of such defective proteins can effectively silence their genes; as a result, tumor cells stop dividing rapidly and revert to a more normal phenotype. Therefore, antisense RNA technology could have a significant impact on cancer gene therapy. Here, we have tried to give comprehensive coverage to some major cases of antisense RNA control of cancer-related genes highlighting the biological systems involved, the efficacy of the antisense RNA in altering target gene function, and how such antisense control affects the malignant phenotype. Furthermore, the therapeutic potential of the antisense technique depends on the in-depth understanding of the target gene function and its role in carcinogenesis.

p53 involvement in activation of the cytokeratin 8 gene in tumor cell lines

We show that the expression of the human cytokeratin 8 (CK8) gene is regulated by wild-type p53. DNA sequence data indicate that the 5' untranslated region of the CK8 gene contains a putative p53-like binding site. In this study we focused on the effect of the p53 protein on the regulation and expression of the CK8 gene. Cotransfection of the H358 p53-negative human lung cancer cell line with a CK8 promoter CAT expression vector and a plasmid expressing the wildtype p53 indicated that p53 induces CK8 expression. A transient assay in which a p53-negative cell line was cotransfected with a CK8 promoter CAT expression vector and a plasmid expressing wildtype or mutant p53 indicated that only wildtype p53 induces the CK8 promoter. Deletion of the putative p53-binding site from the CK8 promoter or introduction of mutations in the p53-binding sequences abolished the wild-type p53-mediated transactivation of CK8. A gel-retardation assay was used to measure DNA binding by the wild-type p53 protein. A 24-bp oligonucleotide corresponding to the putative p53 binding site was used for this assay. The wild-type p53 protein bound weakly to this DNA sequence but much more strongly when three tandem repeat of the binding sequences was used. These studies suggest that the CK8 gene is a downstream target whose expression is regulated by wild-type p53.

A novel NF-kappa B p65 spliced transcript lacking exons 6 and 7 in a non-small cell lung carcinoma cell line

Transcripts of the gene encoding the p65 subunit of the NF-kappa B/Rel transcription factor complex have been reported to undergo alternative splicing to generate one derivative lacking codons for amino acids (aa) 222 to 231 (p65 delta 1) and another that lacks codons for aa 13 to 25 (p65 delta 2) of the conserved Rel homology domain [Narayaran et al., Science 256 (1992) 317-320; Lyle et al., Gene 138 (1994) 265-266]. We have identified a third splicing event in a non-small-cell lung carcinoma cell line that potentially generates a novel p65 mRNA derivative lacking codons for aa 187 to 293 (p65 delta 3) of the Rel homology domain.