Probing human proteins for short encrypted antimicrobial peptides reveals Hs10, a peptide with selective activity for gram-negative bacteria

BACKGROUND

Some cationic and amphiphilic α-helical segments of proteins adsorb to prokaryotic membranes when synthesized as individual polypeptide sequences, resulting in broad and potent antimicrobial activity. However, amphiphilicity, a determinant physicochemical property for peptide-membrane interactions, can also be observed in some β-sheets.

METHODS

The software Kamal was used to scan the human reference proteome for short (7-11 amino acid residues) cationic and amphiphilic protein segments with the characteristic periodicity of β-sheets. Some of the uncovered peptides were chemically synthesized, and antimicrobial assays were conducted. Biophysical techniques were used to probe the molecular interaction of one peptide with phospholipid vesicles, lipopolysaccharides (LPS) and the bacterium Escherichia coli.

RESULTS

Thousands of compatible segments were found in human proteins, five were synthesized, and three presented antimicrobial activity in the micromolar range. Hs10, a nonapeptide fragment of the Complement C3 protein, could inhibit only the growth of tested Gram-negative microorganisms, presenting also little cytotoxicity to human fibroblasts. Hs10 interacted with LPS while transitioning from an unstructured segment to a β-sheet and increased the hydrodynamic radius of LPS particles. This peptide also promoted morphological alterations in E. coli cells.

CONCLUSIONS

Data presented herein introduce yet another molecular template to probe proteins in search for encrypted membrane-active segments and demonstrates that, using this approach, short peptides with low cytotoxicity and high selectivity to prokaryotic cells might be obtained.

GENERAL SIGNIFICANCE

This work widens the biotechnological potential of the human proteome as a source of antimicrobial peptides with application in human health.

Novel disintegrin-like peptides derived from an amphibian skin cDNA sequence of Hypsiboas punctatus

Disintegrins comprise a family of small proteins that bind to and alter the physiological function of integrins, especially integrins that mediate platelet aggregation in blood. Here, we report a lysine-glycine-aspartic acid (KGD) disintegrin-like motif present in a 15-amino acid residue peptide identified in a cDNA library of the amphibian Hypsiboas punctatus skin. The original peptide sequence was used as a template from which five new analogs were designed, chemically synthesized by solid phase, and tested for disintegrin activity and tridimensional structural studies using NMR spectroscopy. The original amphibian peptide had no effect on integrin-mediated responses. Nevertheless, derived peptide analogs inhibited integrin-mediated platelet function, including platelet spreading on fibrinogen.

Genetic switches designed for eukaryotic cells and controlled by serine integrases

Recently, new serine integrases have been identified, increasing the possibility of scaling up genomic modulation tools. Here, we describe the use of unidirectional genetic switches to evaluate the functionality of six serine integrases in different eukaryotic systems: the HEK 293T cell lineage, bovine fibroblasts and plant protoplasts. Moreover, integrase activity was also tested in human cell types of therapeutic interest: peripheral blood mononuclear cells (PBMCs), neural stem cells (NSCs) and undifferentiated embryonic stem (ES) cells. The switches were composed of plasmids designed to flip two different genetic parts driven by serine integrases. Cell-based assays were evaluated by measurement of EGFP fluorescence and by molecular analysis of attL/attR sites formation after integrase functionality. Our results demonstrate that all the integrases were capable of inverting the targeted DNA sequences, exhibiting distinct performances based on the cell type or the switchable genetic sequence. These results should support the development of tunable genetic circuits to regulate eukaryotic gene expression.

Intragenic antimicrobial peptides (IAPs) from human proteins with potent antimicrobial and anti-inflammatory activity

Following the treads of our previous works on the unveiling of bioactive peptides encrypted in plant proteins from diverse species, the present manuscript reports the occurrence of four proof-of-concept intragenic antimicrobial peptides in human proteins, named Hs IAPs. These IAPs were prospected using the software Kamal, synthesized by solid phase chemistry, and had their interactions with model phospholipid vesicles investigated by differential scanning calorimetry and circular dichroism. Their antimicrobial activity against bacteria, yeasts and filamentous fungi was determined, along with their cytotoxicity towards erythrocytes. Our data demonstrates that Hs IAPs are capable to bind model membranes while attaining α-helical structure, and to inhibit the growth of microorganisms at concentrations as low as 1μM. Hs02, a novel sixteen residue long internal peptide (KWAVRIIRKFIKGFIS-NH₂) derived from the unconventional myosin 1h protein, was further investigated in its capacity to inhibit lipopolysaccharide-induced release of TNF-α in murine macrophages. Hs02 presented potent anti-inflammatory activity, inhibiting the release of TNF-α in LPS-primed cells at the lowest assayed concentration, 0.1 μM. A three-dimensional solution structure of Hs02 bound to DPC micelles was determined by Nuclear Magnetic Resonance. Our work exemplifies how the human genome can be mined for molecules with biotechnological potential in human health and demonstrates that IAPs are actual alternatives to antimicrobial peptides as pharmaceutical agents or in their many other putative applications.

Pan Proteome of Xanthomonas campestris pv. campestris Isolates Contrasting in Virulence

Fully sequenced genomes of Xanthomonas campestris pv. campestris (Xcc) strains are reported. However, intra-pathovar differences are still intriguing and far from clear. In this work, the contrasting virulence between two isolates of Xcc - Xcc51 (more virulent) and XccY21 (less virulent) is evaluated by determining their pan proteome profiles. The bacteria are grown in NYG and XVM1 (optimal for induction of hrp regulon) broths and collected at the max-exponential growth phase. Shotgun proteomics reveals a total of 329 proteins when Xcc isolates are grown in XVM1. A comparison of both profiles reveals 47 proteins with significant abundance fluctuations, out of which, 39 show an increased abundance in Xcc51 and are mainly involved in virulence/adaptation mechanisms, genetic information processing, and membrane receptor/iron transport systems, such as BfeA, BtuB, Cap, Clp, Dcp, FyuA, GroEs, HpaG, Tig, and OmpP6. Several differential proteins are further analyzed by qRT-PCR, which reveals a similar expression pattern to the protein abundance. The data shed light on the complex Xcc pathogenicity mechanisms and point out a set of proteins related to the higher virulence of Xcc51. This information is essential for the development of more efficient strategies aiming at the control of black rot disease.

Meloidogyne incognita PASSE-MURAILLE (MiPM) Gene Encodes a Cell-Penetrating Protein That Interacts With the CSN5 Subunit of the COP9 Signalosome

The pathogenicity of phytonematodes relies on secreted virulence factors to rewire host cellular pathways for the benefits of the nematode. In the root-knot nematode (RKN) Meloidogyne incognita, thousands of predicted secreted proteins have been identified and are expected to interact with host proteins at different developmental stages of the parasite. Identifying the host targets will provide compelling evidence about the biological significance and molecular function of the predicted proteins. Here, we have focused on the hub protein CSN5, the fifth subunit of the pleiotropic and eukaryotic conserved COP9 signalosome (CSN), which is a regulatory component of the ubiquitin/proteasome system. We used affinity purification-mass spectrometry (AP-MS) to generate the interaction network of CSN5 in M. incognita-infected roots. We identified the complete CSN complex and other known CSN5 interaction partners in addition to unknown plant and M. incognita proteins. Among these, we described M. incognita PASSE-MURAILLE (MiPM), a small pioneer protein predicted to contain a secretory peptide that is up-regulated mostly in the J2 parasitic stage. We confirmed the CSN5-MiPM interaction, which occurs in the nucleus, by bimolecular fluorescence complementation (BiFC). Using MiPM as bait, a GST pull-down assay coupled with MS revealed some common protein partners between CSN5 and MiPM. We further showed by in silico and microscopic analyses that the recombinant purified MiPM protein enters the cells of Arabidopsis root tips in a non-infectious context. In further detail, the supercharged N-terminal tail of MiPM (NTT-MiPM) triggers an unknown host endocytosis pathway to penetrate the cell. The functional meaning of the CSN5-MiPM interaction in the M. incognita parasitism is discussed. Moreover, we propose that the cell-penetrating properties of some M. incognita secreted proteins might be a non-negligible mechanism for cell uptake, especially during the steps preceding the sedentary parasitic phase.

Rilotumumab plus epirubicin, cisplatin, and capecitabine as first-line therapy in advanced MET-positive gastric or gastro-oesophageal junction cancer (RILOMET-1): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Rilotumumab is a fully human monoclonal antibody that selectively targets the ligand of the MET receptor, hepatocyte growth factor (HGF). We aimed to assess the efficacy, safety, and pharmacokinetics of rilotumumab combined with epirubicin, cisplatin, and capecitabine, and to assess potential biomarkers, in patients with advanced MET-positive gastric or gastro-oesophageal junction adenocarcinoma.

METHODS

This multicentre, randomised, double-blind, placebo-controlled, phase 3 study was done at 152 centres in 27 countries. We recruited adults (aged ≥18 years) with unresectable locally advanced or metastatic gastric or gastro-oesophageal junction adenocarcinoma, an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, MET-positive tumours (≥25% of tumour cells with membrane staining of ≥1+ staining intensity), and evaluable disease, who had not received previous systemic therapy. Eligible patients were randomly assigned (1:1) via a computerised voice response system to receive rilotumumab 15 mg/kg intravenously or placebo in combination with open-label chemotherapy (epirubicin 50 mg/m² intravenously; cisplatin 60 mg/m² intravenously; capecitabine 625 mg/m² orally twice daily) in 21-day cycles for up to ten cycles. After completion of chemotherapy, patients continued to receive rilotumumab or placebo monotherapy until disease progression, intolerability, withdrawal of consent, or study termination. Randomisation was stratified by disease extent and ECOG performance status. Both patients and physicians were masked to study treatment assignment. The primary endpoint was overall survival, analysed by intention to treat. We report the final analysis. This study is registered with ClinicalTrials.gov, number NCT01697072.

FINDINGS

Between Nov 7, 2012, and Nov 21, 2014, 609 patients were randomly assigned to rilotumumab plus epirubicin, cisplatin, and capecitabine (rilotumumab group; n=304) or placebo plus epirubicin, cisplatin, and capecitabine (placebo group; n=305). Study treatment was stopped early after an independent data monitoring committee found a higher number of deaths in the rilotumumab group than in the placebo group; all patients in the rilotumumab group subsequently discontinued all study treatment. Median follow-up was 7·7 months (IQR 3·6-12·0) for patients in the rilotumumab group and 9·4 months (5·3-13·1) for patients in the placebo group. Median overall survival was 8·8 months (95% CI 7·7-10·2) in the rilotumumab group compared with 10·7 months (9·6-12·4) in the placebo group (stratified hazard ratio 1·34, 95% CI 1·10-1·63; p=0·003). The most common grade 3 or worse adverse events in the rilotumumab and placebo groups were neutropenia (86 [29%] of 298 patients vs 97 [32%] of 299 patients), anaemia (37 [12%] vs 43 [14%]), and fatigue (30 [10%] vs 35 [12%]). The frequency of serious adverse events was similar in the rilotumumab and placebo groups (142 [48%] vs 149 [50%]). More deaths due to adverse events occurred in the rilotumumab group than the placebo group (42 [14%] vs 31 [10%]). In the rilotumumab group, 33 (11%) of 298 patients had fatal adverse events due to disease progression, and nine (3%) had fatal events not due to disease progression. In the placebo group, 23 (8%) of 299 patients had fatal adverse events due to disease progression, and eight (3%) had fatal events not due to disease progression.

INTERPRETATION

Ligand-blocking inhibition of the MET pathway with rilotumumab is not effective in improving clinical outcomes in patients with MET-positive gastric or gastro-oesophageal adenocarcinoma.

FUNDING

Amgen.

Comparative NanoUPLC-MSE analysis between magainin I-susceptible and -resistant Escherichia coli strains

In recent years the antimicrobial peptides (AMPs) have been prospected and designed as new alternatives to conventional antibiotics. Indeed, AMPs have presented great potential toward pathogenic bacterial strains by means of complex mechanisms of action. However, reports have increasingly emerged regarding the mechanisms by which bacteria resist AMP administration. In this context, we performed a comparative proteomic study by using the total bacterial lysate of magainin I-susceptible and –resistant E. coli strains. After nanoUPLC-MS^E analyses we identified 742 proteins distributed among the experimental groups, and 25 proteins were differentially expressed in the resistant strains. Among them 10 proteins involved in bacterial resistance, homeostasis, nutrition and protein transport were upregulated, while 15 proteins related to bacterial surface modifications, genetic information and β-lactams binding-protein were downregulated. Moreover, 60 exclusive proteins were identified in the resistant strains, among which biofilm and cell wall formation and multidrug efflux pump proteins could be observed. Thus, differentially from previous studies that could only associate single proteins to AMP bacterial resistance, data here reported show that several metabolic pathways may be related to E. coli resistance to AMPs, revealing the crucial role of multiple “omics” studies in order to elucidate the global molecular mechanisms involved in this resistance.

BRAZILIAN CONSENSUS FOR MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 3: CONTROVERSIES AND UNRESECTABLE METASTASES

In the last module of this consensus, controversial topics were discussed. Management of the disease after progression during first line chemotherapy was the first discussion. Next, the benefits of liver resection in the presence of extra-hepatic disease were debated, as soon as, the best sequence of treatment. Conversion chemotherapy in the presence of unresectable liver disease was also discussed in this module. Lastly, the approach to the unresectable disease was also discussed, focusing in the best chemotherapy regimens and hole of chemo-embolization.

Plant responses to tomato chlorotic mottle virus: Proteomic view of the resistance mechanisms to a bipartite begomovirus in tomato

Tomato chlorotic mottle virus (ToCMoV) is a widespread bipartite Begomovirus species found in tomato fields in Brazil. In this study, plant responses and putative mechanisms associated with the 'Tyking'-derived recessive resistance to ToCMoV were investigated. Changes in the protein profile in the inoculated plants of two near isogenic tomato lines resistant ('LAM 157') and susceptible ('Santa Clara') to ToCMoV were analyzed. Seedlings were biolistically inoculated with an infectious ToCMoV clone. Leaves from infected plants (confirmed by PCR) were sampled at 15days after inoculation. Proteins were extracted using phenol and analyzed by shotgun MS (2D-nanoUPLC/HDMS^E). Out of the 534 identified proteins, 82 presented statistically significant differences in abundance, including 35 unique proteins displayed in the resistant tomato inoculated with ToCMoV. Proteins associated to chromatin structure, cytoskeleton structure, cuticle biosynthesis, and ubiquitin pathway were identified and their putative roles during virus infection process were discussed. The protein profile analysis allowed for the development of a hypothetical model showing how the resistant host cell responds to ToCMoV infection. The data obtained provide a better understanding of resistant mechanisms used by the host plant to contain viral infection and could be the basis for further investigation in other plant-begomovirus pathosystems.

BIOLOGICAL SIGNIFICANCE

In this study we propose a model of resistance to begomovirus in tomato and highlight host proteins, which could be targets for future investigations in plant-begomovirus pathosystems.

Engineering soya bean seeds as a scalable platform to produce cyanovirin-N, a non-ARV microbicide against HIV

There is an urgent need to provide effective anti-HIV microbicides to resource-poor areas worldwide. Some of the most promising microbicide candidates are biotherapeutics targeting viral entry. To provide biotherapeutics to poorer areas, it is vital to reduce the cost. Here, we report the production of biologically active recombinant cyanovirin-N (rCV-N), an antiviral protein, in genetically engineered soya bean seeds. Pure, biologically active rCV-N was isolated with a yield of 350 μg/g of dry seed weight. The observed amino acid sequence of rCV-N matched the expected sequence of native CV-N, as did the mass of rCV-N (11 009 Da). Purified rCV-N from soya is active in anti-HIV assays with an EC50 of 0.82-2.7 nM (compared to 0.45-1.8 nM for E. coli-produced CV-N). Standard industrial processing of soya bean seeds to harvest soya bean oil does not diminish the antiviral activity of recovered rCV-N, allowing the use of industrial soya bean processing to generate both soya bean oil and a recombinant protein for anti-HIV microbicide development.

NanoUPLC/MS(E) proteomic analysis reveals modulation on left ventricle proteome from hypertensive rats after exercise training

NanoUPLC/MS(E) was used to verify the effects of 8weeks of low (SHR-LIT=4) and high (SHR-HIT=4) intensity training over the left ventricle proteome of hypertensive rats (SHR-C=4). Training enhanced the aerobic capacity and reduced the systolic blood pressure in all exercised rats. NanoUPLC/MS(E) identified 250 proteins, with 233 in common to all groups and 16 exclusive to SHR-C, 2 to SHR-LIT, and 2 to the SHR-HIT. Cardiac hypertrophy related proteins appeared only in SHR-C. The SHR-LIT enhanced the abundance of 30 proteins and diminished 6, while SHR-HIT enhanced the abundance of 39 proteins and reduced other 7. The levels of metabolic (β and γ-enolase, adenine phosphoribosultransferase, and cytochrome b-c1), myofibril (myosin light chain 4, tropomyosin α and β-chain), and transporter proteins (hemoglobin, serum albumin, and hemopexin) were increased by both intensities. Transcription regulator and histone variants were enhanced by SHR-LIT and SHR-HIT respectively. SHR-LIT reduced the concentration of myosin binding protein C, while desmin and membrane voltage dependent anion selective channel protein-3 were reduced only by SHR-HIT. In addition, polyubiquitin B and C, and transcription regulators decreased in both intensities. Exercise also increased the concentration of anti-oxidant proteins, peroxiredozin-6 and glutathione peroxidase-1.

BIOLOGICAL SIGNIFICANCE

Pathologic left ventricle hypertrophy if one of the major outcomes of hypertension being a strong predictor of heart failure. Among the various risk factors for cardiovascular disorders, arterial hypertension is responsible for the highest rates of mortality worldwide. In this way, this present study contribute to the understanding of the molecular mechanisms involved in the attenuation of hypertension and the regression of pathological cardiac hypertrophy induced by exercise training.

Mass spectrometry characterisation of fatty acids from metabolically engineered soybean seeds

Improving the quality and performance of soybean oil as biodiesel depends on the chemical composition of its fatty acids and requires an increase in monounsaturated acids and a reduction in polyunsaturated acids. Despite its current use as a source of biofuel, soybean oil contains an average of 25 % oleic acid and 13 % palmitic acid, which negatively impacts its oxidative stability and freezing point, causing a high rate of nitrogen oxide emission. Gas chromatography and ion mobility mass spectrometry were conducted on soybean fatty acids from metabolically engineered seed extracts to determine the nature of the structural oleic and palmitic acids. The soybean genes FAD2-1 and FatB were placed under the control of the 35SCaMV constitutive promoter, introduced to soybean embryonic axes by particle bombardment and down-regulated using RNA interference technology. Results indicate that the metabolically engineered plants exhibited a significant increase in oleic acid (up to 94.58 %) and a reduction in palmitic acid (to <3 %) in their seed oil content. No structural differences were observed between the fatty acids of the transgenic and non-transgenic oil extracts.

RILOMET-1: An international phase III multicenter, randomized, double-blind, placebo-controlled trial of rilotumumab plus epirubicin, cisplatin, and capecitabine (ECX) as first-line therapy in patients with advanced MET-positive gastric or gastroesophageal junction (G/GEJ) adenocarcinoma

TPS4153

Background: Rilotumumab is an investigational, fully human monoclonal antibody to hepatocyte growth factor/scatter factor that inhibits signaling through the MET receptor. In a randomized phase II study in patients with advanced G/GEJ adenocarcinoma, addition of rilotumumab every 3 weeks (Q3W) to ECX showed trends toward improved overall survival (OS) and progression-free survival (PFS) compared with ECX alone. In patients with high tumor MET expression and high rilotumumab exposure, the treatment effect of rilotumumab combined with ECX was significantly enhanced. Methods: In this phase III study, patients (planned N=450) are randomized 1:1 to ECX (intravenous [IV] epirubicin 50 mg/m2 on day 1, IV cisplatin 60 mg/m2 on day 1, and oral capecitabine 625 mg/m2 twice daily on days 1−21) plus double-blind rilotumumab 15 mg/kg or placebo IV Q3W. Randomization is stratified by disease extent (locally advanced vs metastatic) and Eastern Cooperative Oncology Group (ECOG) score (0 vs 1). Key eligibility criteria include previously untreated, pathologically confirmed unresectable locally advanced or metastatic G/GEJ adenocarcinoma; ECOG score 0 or 1; ≥18 years old; MET-positive by centralized immunohistochemistry; HER2-negative; adequate organ function; and ≥6 months since neoadjuvant/adjuvant therapy. The primary endpoint is OS. Key secondary endpoints include PFS, 12-month survival rate, objective response, OS in MET expression tertiles, safety, and pharmacokinetics. An exploratory objective is to assess associations between outcomes and tumor and circulating biomarkers. Enrollment began in November 2012, and the trial continues to accrue. An independent data monitoring committee will conduct planned interim reviews for safety and efficacy. Status: recruiting participants. Sponsored by Amgen Inc. Clinical trial information: NCT01697072.

Detection and expression analysis of recombinant proteins in plant-derived complex mixtures using nanoUPLC-MS(E)

The use of mass spectrometry to identify recombinant proteins that are expressed in total soluble proteins (TSPs) from plant extracts is necessary to accelerate further processing steps. For example, the method consists of TSP sample preparation and trypsin digestion prior to the preliminary characterization using nanoUPLC-MS(E) analysis of the recombinant proteins that are expressed in TSP samples of transgenic soybean seeds. A TSP sample as small as 50 μg can be effectively analyzed. In this study, transgenic soybean seeds that expressed recombinant cancer testis antigen (CTAG) were used. The procedure covered 30% of the protein sequence and was quantified at 0.26 ng, which corresponded to 0.1% of the TSP sample. A comparative proteomic profile was generated by the comparison of a negative control and sample that showed a unique expression pattern of CTAG in a transgenic line. The experimental data from the TSP extraction, sample preparation and data analysis are discussed herein.

Accumulation of functional recombinant human coagulation factor IX in transgenic soybean seeds

The seed-based production of recombinant proteins is an efficient strategy to achieve the accumulation, correct folding, and increased stability of these recombinant proteins. Among potential plant molecular farming systems, soybean [Glycine max (L.) Merrill] is a viable option for the production of recombinant proteins due to its high protein content, known regulatory sequences, efficient gene transfer protocols, and a scalable production system under greenhouse conditions. We report here the expression and stable accumulation of human coagulation factor IX (hFIX) in transgenic soybean seeds. A biolistic process was utilised to co-introduce a plasmid carrying the hFIX gene under the transcriptional control of the α' subunit of a β-conglycinin seed-specific promoter and an α-Coixin signal peptide in soybean embryonic axes from mature seeds. The 56-kDa hFIX protein was expressed in the transgenic seeds at levels of up to 0.23% (0.8 g kg(-1) seed) of the total soluble seed protein as determined by an enzyme-linked immunosorbent assay (ELISA) and western blot. Ultrastructural immunocytochemistry assays indicated that the recombinant hFIX in seed cotyledonary cells was efficiently directed to protein storage vacuoles. Mass spectrometry characterisation confirmed the presence of the hFIX recombinant protein sequence. Protein extracts from transgenic seeds showed a blood-clotting activity of up to 1.4% of normal plasma. Our results demonstrate the correct processing and stable accumulation of functional hFIX in soybean seeds stored for 6 years under room temperature conditions (22 ± 2°C).

Expression of functional recombinant human growth hormone in transgenic soybean seeds

We produced human growth hormone (hGH), a protein that stimulates growth and cell reproduction, in genetically engineered soybean [Glycine max (L.) Merrill] seeds. Utilising the alpha prime (α') subunit of β-conglycinin tissue-specific promoter from soybean and the α-Coixin signal peptide from Coix lacryma-jobi, we obtained transgenic soybean lines that expressed the mature form of hGH in their seeds. Expression levels of bioactive hGH up to 2.9% of the total soluble seed protein content (corresponding to approximately 9 g kg(-1)) were measured in mature dry soybean seeds. The results of ultrastructural immunocytochemistry assays indicated that the recombinant hGH in seed cotyledonary cells was efficiently directed to protein storage vacuoles. Specific bioassays demonstrated that the hGH expressed in the soybean seeds was fully active. The recombinant hGH protein sequence was confirmed by mass spectrometry characterisation. These results demonstrate that the utilisation of tissue-specific regulatory sequences is an attractive and viable option for achieving high-yield production of recombinant proteins in stable transgenic soybean seeds.

Soybeans as bioreactors for biopharmaceuticals and industrial proteins

Plants present various advantages for the production of biomolecules, including low risk of contamination with prions, viruses and other pathogens, scalability, low production costs, and available agronomical systems. Plants are also versatile vehicles for the production of recombinant molecules because they allow protein expression in various organs, such as tubers and seeds, which naturally accumulate large amounts of protein. Among crop plants, soybean is an excellent protein producer. Soybean plants are also a good source of abundant and cheap biomass and can be cultivated under controlled greenhouse conditions. Under containment, the plant cycle can be manipulated and the final seed yield can be maximized for large-scale protein production within a small and controlled area. Exploitation of specific regulatory sequences capable of directing and accumulating recombinant proteins in protein storage vacuoles in soybean seeds, associated with recently developed biological research tools and purification systems, has great potential to accelerate preliminary characterization of plant-derived biopharmaceuticals and industrial macromolecules. This is an important step in the development of genetically engineered products that are inexpensive and safe for medicinal, food and other uses.

Correct targeting of proinsulin in protein storage vacuoles of transgenic soybean seeds

Soybean plants are promising bioreactors for the expression of biochemically complex proteins that cannot be produced in a safe and/or economically viable way in microorganisms, eukaryotic culture cells or secreted by transgenic animal glands. Soybeans present many desirable agronomic characteristics for high scale protein production, such as high productivity, short reproductive cycle, photoperiod sensitivity, and natural organs destined for protein accumulation in the seeds. The significant similarities between plant and human cells in terms of protein synthesis processes, folding, assembly, and post-translational processing are important for efficient accumulation of recombinant proteins. We obtained two transgenic lines using biolystics, incorporating the human proinsulin gene under control of the monocot tissue-specific promoter from sorghum gamma-kafirin seed storage protein gene and the alpha-coixin cotyledonary vacuolar signal peptide from Coix lacryma-jobi (Poaceae). Transgenic plants expressed the proinsulin gene and accumulated the polypeptide in mature seeds. Protein targeting to cotyledonary protein storage vacuoles was successfully achieved and confirmed with immunocytochemistry assays. The combination of different regulatory sequences was apparently responsible for high stability in protein accumulation, since human proinsulin was detected after seven years under room temperature storage conditions.

Novel insights on the mechanism of action of alpha-amylase inhibitors from the plant defensin family

Plant defensins are small cysteine-rich proteins commonly synthesized in plants, encoded by large multigene families. Most plant defensins that have been characterized to date show potent antifungal and/or bactericidal activities. This report describes VuD1, an unusual defensin that is able to inhibit insect-pest alpha-amylases. VuD1 was cloned from cowpea (Vigna unguiculata) seeds and expressed in a heterologous system. Inhibitory enzyme assays showed that VuD1 efficiently inhibits alpha-amylases from the weevils Acanthoscelides obtectus and Zabrotes subfasciatus, caused low inhibition toward mammalian enzymes and was unable to inhibit the alpha-amylases from Callosobruchus maculatus and Aspergillus fumigatus. To shed some light over the mechanism of action of VuD1, molecular modeling analyses were performed, revealing that the N-terminus of the molecule is responsible for binding with the active site of weevil enzymes. Moreover, models of VuD1 and mammalian enzymes were also generated to elucidate the specificity mechanisms. The data presented herein suggests that this defensin has potential application in the development of transgenic plants for insect pest control.

Identification of a novel storage glycine-rich peptide from guava (Psidium guajava) seeds with activity against Gram-negative bacteria

Bacterial pathogens cause an expressive negative impact worldwide on human health, with ever increasing treatment costs. A significant rise in resistance to commercial antibiotics has been observed in pathogenic bacteria responsible for urinary and gastro-intestinal infections. Towards the development of novel approaches to control such common infections, a number of defense peptides with antibacterial activities have been characterized. In this report, the peptide Pg-AMP1 was isolated from guava seeds (Psidium guajava) and purified using a Red-Sepharose Cl-6B affinity column followed by a reversed-phase HPLC (Vydac C18-TP). Pg-AMP1 showed no inhibitory activity against fungi, but resulted in a clear growth reduction in Klebsiella sp. and Proteus sp., which are the principal pathogens involved in urinary and gastro-intestinal hospital infections. SDS-PAGE and mass spectrometry (MALDI-ToF) characterized Pg-AMP1 a monomer with a molecular mass of 6029.34Da and small quantities of a homodimer. Amino acid sequencing revealed clear identity to the plant glycine-rich protein family, with Pg-AMP1 the first such protein with activity towards Gram-negative bacteria. Furthermore, Pg-AMP1 showed a 3D structural homology to an enterotoxin from Escherichia coli, and other antibacterial proteins, revealing that it might act by formation of a dimer. Pg-AMP1 shows potential, in a near future, to contribute to development of novel antibiotics from natural sources.

Cloning and structural analysis of an Indian little millet (Panicum sumatrense) zein-like storage protein: implications for molecular assembly

Zeins are prolamin storage proteins that accumulate in kernel endosperm of several cereals. For cloning of genes coding for zein-like proteins that accumulate in enhanced quantities in the filling stages of little millet (Panicum sumatrense Roth.) developing grains, RT-PCR was performed using specific primers. A 750-bp cDNA was directly sequenced and in silico analysis showed high identity degree to alpha-prolamins. This family is composed of zeins from Zea mays, coixins from Coix lachryma-jobi, and alpha-kafirins from Sorghum bicolor. The putative conserved domain of zein-like proteins was identified by primary structure comparisons. Furthermore, threading analyses indicated that the millet zein-like protein forms an anti-parallel alpha-helical hairpin with two opposite surfaces: one hydrophobic and the other hydrophilic that probably could be involved in protein storage assembly. Knowledge about zein-like alpha-prolamins in little millet will lead to cloning and transfer of this gene to other major food crops, such as cereals and legumes, with inferior nutritional quality for monogastric animals.

Screening and secretomic analysis of enthomopatogenic Beauveria bassiana isolates in response to cowpea weevil (Callosobruchus maculatus) exoskeleton

The production of cowpea (Vigna unguiculata), an important self-sustained crop in Latin America and Africa, is severely affected by damage by the cowpea weevil Callosobruchus maculatus. The presence of a single larva in stored seeds can lead to losses of almost 40%. Control of C. maculatus currently relies on the inefficient use of chemical insecticides and post-harvest treatments. The use of entomopathogenic fungus became a reliable alternative for coleopteran pest control and has been extensively investigated. Among them, Beauveria bassiana and Metarhizium anisopliae were widely evaluated in order to measure their virulence toward many insects. In this report, we evaluated the insecticidal activity of ten strains of B. bassiana and the most lethal fungi strains were analyzed for proteinaceous secretions by two dimensional electrophoresis and for enzyme activities, including chitinolytic, proteolytic and alpha-amylolytic activities. This study could, in the near future, help to establish novel biotechnological tools to use for cowpea weevil control.

Phase II multicenter trial of docetaxel, epirubicin, and 5-fluorouracil (DEF) in the treatment of advanced gastric cancer: a novel, safe, and active regimen

BACKGROUND

This study evaluated the efficacy and safety of docetaxel, epirubicin, and 5-fluorouracil (5-FU) [DEF] as treatment for locally advanced unresectable or metastatic gastric cancer.

METHODS

Thirty-seven patients participated in the study (median age, 56 years; range, 22-73 years); Eastern Cooperative Oncology Group performance status [PS], 0-2). Docetaxel 75 mg/m2 IV (day 1), 5-FU 500 mg/m2 IV (days 1-3), and epirubicin 50 mg/m2 IV (day 1) were administered every 3 weeks for six cycles.

RESULTS

In total, 20/37 patients (54%) completed six treatment cycles. Thirteen patients (35%; 95% confidence intervals [CI], 20% to 51%) had an objective response; 1 patient (3%) achieved a complete response and 12 patients (32%) achieved partial responses. Stable disease was observed in 7 patients (19%) and progressive disease in 5 patients (14%). Twelve patients (32%) were unevaluable. Clinical benefit (based on PS, weight gain, and analgesic consumption) was observed in 11 patients (30%). Median follow-up was 41 months (range, 26-53 months), median time to progression was 6.6 months (range, 0.5-29.2 months), median overall survival was 10.7 months (range, 7.0-14.6 months), and 1-year survival was 40%. The regimen was well tolerated. Grade 3-4 febrile neutropenia occurred in 8 patients (22%; 6% of cycles) and grade 3-4 neutropenia in 1 patient (1% of cycles). The most frequent grade 3-4 toxicities were alopecia (11% of cycles), diarrhea (4% of cycles) and vomiting (2% of cycles); grade 1-2 asthenia and fatigue occurred in 43% of cycles.

CONCLUSION

DEF is effective in the treatment of advanced gastric cancer, and has a good safety profile.

Screening of entomopathogenic Metarhizium anisopliae isolates and proteomic analysis of secretion synthesized in response to cowpea weevil (Callosobruchus maculatus) exoskeleton

Cowpea crops are severely attacked by Callosobruchus maculatus, a Coleopteran that at the larval stage penetrates into stored seeds and feeds on cotyledons. Cowpea weevil control could be based in utilization of bacteria and fungi to reduce pest development. Entomopathogenic fungi, such as Metarhizium anisopliae, are able to control insect-pests and are widely applied in biological control. This report evaluated ten M. anisopliae isolates according to their virulence, correlating chitinolytic, proteolytic and alpha-amylolytic activities, as well proteomic analysis by two dimensional gels of fungal secretions in response to an induced medium containing C. maculatus shells, indicating novel biotechnological tools capable of improving cowpea crop resistance.

Structure and enzyme properties of Zabrotes subfasciatus alpha-amylase

Digestive alpha-amylases play an essential role in insect carbohydrate metabolism. These enzymes belong to an endo-type group. They catalyse starch hydrolysis, and are involved in energy production. Larvae of Zabrotes subfasciatus, the Mexican bean weevil, are able to infest stored common beans Phaseolus vulgaris, causing severe crop losses in Latin America and Africa. Their alpha-amylase (ZSA) is a well-studied but not completely understood enzyme, having specific characteristics when compared to other insect alpha-amylases. This report provides more knowledge about its chemical nature, including a description of its optimum pH (6.0 to 7.0) and temperature (20-30 degrees C). Furthermore, ion effects on ZSA activity were also determined, showing that three divalent ions (Mn2+, Ca2+, and Ba2+) were able to enhance starch hydrolysis. Fe2+ appeared to decrease alpha-amylase activity by half. ZSA kinetic parameters were also determined and compared to other insect alpha-amylases. A three-dimensional model is proposed in order to indicate probable residues involved in catalysis (Asp204, Glu240, and Asp305) as well other important residues related to starch binding (His118, Ala206, Lys207, and His304).

Paclitaxel and gemcitabine as salvage treatment in metastatic breast cancer

Both paclitaxel and gemcitabine (Gemzar) have shown activity and manageable toxicity when used as single agents in heavily pretreated patients with metastatic breast cancer. This phase II study evaluated their use in combination for metastatic breast cancer patients whose disease recurred or progressed following treatment with anthracycline-containing regimens. Twenty-nine patients ranging from 32 to 68 years of age received paclitaxel at 175 mg/m2 i.v. over 3 hours on day 1 and gemcitabine at 1,000 mg/m2 i.v. on days 1, 8, and 15 every 28 days. Because of unacceptable thrombocytopenia in the first five patients, the gemcitabine schedule was changed to days 1 and 8 of a 21-day cycle for the remainder of the study. All 29 patients were evaluable for response and toxicity. Seventeen patients (59%) were considered truly anthracycline- or anthracenedione-refractory. A total of 137 cycles (median: 4 per patient) were administered. The regimen was well tolerated. Grade 3/4 thrombocytopenia was observed in 5 (18.5%) of the first 27 cycles and in 6 (5.4%) of the 110 cycles following dosage reduction (P = .04). Five patients had grade 1 and two patients had grade 3 neuropathy. Eight patients had grade 3 neutropenia, two had grade 4 neutropenia with fever at the higher dosage, and eight had grade 1/2 myalgia and fatigue. Five patients (17%) had a complete response and 11 (38%) a partial response, yielding an objective response rate of 55% (95% confidence interval = 36%-73%). Six patients (20.7%) had stable disease. Median response duration was 8 months (range: 4-26 months), and median overall survival was 12 months (range: 4-48+ months). Survival at 1, 2, 3, and 4 years was 45%, 30%, 20%, and 10%, respectively. The combination of paclitaxel on day 1 with gemcitabine on days 1 and 8 of a 21-day cycle appears to have promising activity in heavily pretreated patients with metastatic breast cancer. Phase III trials comparing this promising doublet to paclitaxel monotherapy and to other chemotherapeutic strategies for advanced breast cancer will clarify the role of this regimen.

Transcript profiling in Candida albicans reveals new cellular functions for the transcriptional repressors CaTup1, CaMig1 and CaNrg1

The pathogenic fungus, Candida albicans contains homologues of the transcriptional repressors ScTup1, ScMig1 and ScNrg1 found in budding yeast. In Saccharomyces cerevisiae, ScMig1 targets the ScTup1/ScSsn6 complex to the promoters of glucose repressed genes to repress their transcription. ScNrg1 is thought to act in a similar manner at other promoters. We have examined the roles of their homologues in C. albicans by transcript profiling with an array containing 2002 genes, representing about one quarter of the predicted number of open reading frames (ORFs) in C. albicans. The data revealed that CaNrg1 and CaTup1 regulate a different set of C. albicans genes from CaMig1 and CaTup1. This is consistent with the idea that CaMig1 and CaNrg1 target the CaTup1 repressor to specific subsets of C. albicans genes. However, CaMig1 and CaNrg1 repress other C. albicans genes in a CaTup1-independent fashion. The targets of CaMig1 and CaNrg1 repression, and phenotypic analyses of nrg1/nrg1 and mig1/mig1 mutants, indicate that these factors play differential roles in the regulation of metabolism, cellular morphogenesis and stress responses. Hence, the data provide important information both about the modes of action of these transcriptional regulators and their cellular roles. The transcript profiling data are available at http://www.pasteur.fr/recherche/unites/RIF/transcriptdata/.

Phase II trial of the use of paclitaxel and gemcitabine as a salvage treatment in metastatic breast cancer

The purpose of this study was to evaluate gemcitabine plus paclitaxel in heavily pretreated patients with metastatic breast cancer (MBC). Patients with MBC with second or third relapse to anthracycline-containing regimens received a 3-hour infusion of paclitaxel 175 mg/m2 on day 1, and gemcitabine 1.0 g/m2 on days 1, 8, and 15, every 28 days. Because of unacceptable thrombocytopenia seen in the first 5 patients, the gemcitabine schedule was changed to days 1 and 8 (G-1,8) for the remainder of the study, every 21 days. Twenty-nine patients (median age, 46 years; range, 32-68 years) received 137 cycles (median: 4 per patient). The regimen was well tolerated. World Health Organization grades III and IV thrombocytopenia were observed in 5 (18.5%) of the first 27 cycles (G-1,8,15), and in 6 (5.4%) of the 110 subsequent cycles (G-1,8)--p = 0.04 for the difference between schedules. Five patients had grade I and two had grade III neuropathy. Eight patients had grade III neutropenia, two had grade IV neutropenia associated with fever (G-1,8,15), and eight had grades I and II myalgia and fatigue. There were 16 (55%) objective responses (95% CI 36-73%); 5 (17%) complete responses, 11 (38%) partial responses (95% CI 3-30% and 19-56%, respectively), and 6 (20.5%) patients with stable disease. Median response duration was 8 months (range, 4-26 months). Median overall survival was 12 months (range, 4-28+ months), and 1-year and 2-year survival rates were 45% and 30%, respectively. This phase II study demonstrated a manageable toxicity profile with the gemcitabine day 1, 8 schedule in combination with paclitaxel and significant and promising activity in heavily pretreated patients with MBC. A confirmatory phase III trial is warranted.

Gemcitabine and paclitaxel as salvage therapy in metastatic breast cancer

In a phase II trial, 29 patients with anthracycline-pretreated or anthracycline-resistant metastatic breast cancer in whom anthracycline-containing first- or second-line chemotherapy failed received combination paclitaxel (Taxol)/gemcitabine (Gemzar). The initial regimen of paclitaxel at 175 mg/m2 on day 1 and gemcitabine at 1,000 mg/m2 on days 1, 8, and 15 of a 28-day cycle was given to five patients for a total of 27 cycles. The regimen resulted in excessive thrombocytopenia and was subsequently changed to gemcitabine at the same dose on days 1 and 8 of a 21-day cycle, with study treatment being given for a maximum of eight cycles. This regimen was well tolerated. Further evaluation of this regimen in minimally and heavily pretreated patients with advanced breast cancer is warranted.

Phase II trial of the combination of paclitaxel and 5-fluorouracil in the treatment of advanced gastric cancer: a novel, safe, and effective regimen

This prospective phase II clinical trial was performed to explore the activity and efficacy of the combination of paclitaxel and 5-fluorouracil in the treatment of advanced gastric adenocarcinoma. Thirty-one patients ages 18 to 70 years, with Karnofsky performance status (KPS) >50, adequate cardiac, renal, and hepatic functions, measurable metastatic or locally unresectable disease, life expectancy > or =3 months, signed written informed consent, and without any previous chemotherapy were assigned to receive on an outpatient basis: paclitaxel--175 mg/m2, in a 3-hour infusion on day 1 and 5-fluorouracil--1.5 g/m2, also in a 3-hour infusion on day 2 every 21 days, for a maximum of seven cycles. A system to assess clinical benefit based on KPS, analgesic consumption, and weight gain was also used in this trial. Median age was 61 years (range, 31-70 years). The 29 patients eligible for response and toxicity evaluation underwent 147 cycles of chemotherapy. There were 19 (65.5%) objective responses (95% confidence interval: 48%-83%), including 7 (24.1%) complete responses and 12 (41.4%) partial responses. Three patients had the complete response pathologically confirmed. In three of six patients who went to second-look laparotomy, a potentially curative esophagogastrectomy was possible. The toxicity of this combination was considered low, predictable, and manageable and was characterized mainly by reversible alopecia, peripheral neuropathy, myalgia, and mild neutropenia. Fifteen (51.7%) patients attained a clinical benefit response. The median overall survival was 12 months (range, 2-30+ months) and the 30-month overall survival was 20%. This novel regimen appears to be very effective in advanced gastric cancer. The projected 2-year survival of 20% is higher than that achieved with other first-line regimens. These encouraging results indicate the need for further studies to confirm the merit of this regimen.

Chemotherapy for Advanced Gastric Cancer: Focus on New Agents and Combinations

BACKGROUND: Although many treatments for advanced gastric cancer have been developed, systemic therapy remains elusive. METHODS: The author reviewed data on recent phase II and III trials of the main new agents and combinations. RESULTS: Chemotherapy appears to improve survival of patients with advanced disease, albeit slightly. New drugs that might improve response rates and survival include the taxanes. CONCLUSIONS: New combinations, including the taxanes, must be designed and evaluated to further improve the outcome for patients with advanced gastric cancer.

Phase II trial of paclitaxel and ifosfamide as a salvage treatment in metastatic breast cancer

PURPOSE

Treatment results in patients failing first-line chemotherapy in metastatic breast cancer (MBC) are still unsatisfactory, with patients exhibiting poor responses to salvage therapy and a short overall survival. Both paclitaxel and ifosfamide are able to produce objective tumor responses in this disease. Therefore, the antitumor effects and toxicity of their combined use could be worthwhile studying in patients progressing after doxorubicin-containing combinations.

PATIENTS AND METHODS

This Phase II trial of paclitaxel/ifosfamide included patients with bi-dimensionally measurable metastatic breast cancer in second or third relapse, following anthracycline-containing regimens; ECOG PS < 2, and adequate hepatic, cardiac, renal, and hematological functions. Paclitaxel 175 mg/m2 was given on day 1, in a 3-hour infusion with appropriate antiallergic pre-medication; while ifosfamide 1.8 g/m2 was given on days 2, 3, 4 with mesna 360 mg/m2 i.v., 15 minutes before and 4 hours after ifosfamide administration, and 720 mg/m2 P.O. 8 hours later at home, also on days 2, 3, 4. The cycles were repeated every 21 days, on an outpatient basis.

RESULTS

Twenty-four patients were accrued for the study and 23 were considered eligible for the evaluation of toxicity and response. Previous chemotherapy included: CMF/FAC (16 cases); CMF plus mitoxantrone/FAC/cisplatin, vinblastine, mitomycin C (2 cases): and FAC/mitomycin C, vinblastine, and etoposide (5 cases). There were 11 (48%) objective responses (95% C.I.:27-69%), including 2 (9%) CR and 9 (39%) PR (95% C.I.:0-21% and 19-61%, respectively). Five (22%) patients attained disease stabilization. Median response duration was 7+ months (range 4 to 20+), and the median overall survival was 12 months (range 4-23+). The regimen was well tolerated. WHO nausea/ vomiting grades 1-2, alopecia grade 3, and neutropenia grades 1-2 were seen in most patients. Four patients experienced mild neuropathy, while it was grade 3 in 1 case. Seven patients had grade 3 neutropenia. In addition, grade 4 neutropenia associated with fever was documented in other 4 cases. No hypersensitivity reactions were seen. One case of reversible tachycardia after drug administration was seen. Myalgia grades 1-2 was also reported in some patients.

CONCLUSION

These results suggest that the present regimen has significant activity in heavily pretreated patients with a MBC, with a manageable toxicity profile. Further trials exploiting the above mentioned drug combination are warranted.

Phase II trial of bleomycin, ifosfamide, and carboplatin in metastatic cervical cancer

PURPOSE

A bleomycin, carboplatin, and ifosfamide (BIC) chemotherapy protocol was designed to evaluate tumor response and palliation in patients with advanced cervical cancer.

PATIENTS AND METHODS

Forty patients with stage IV primary or recurrent squamous cell carcinoma of the cervix (19 previously irradiated and 21 nonirradiated) were assigned to treatment with six cycles of BIC: bleomycin, 30 mg bolus on day 1; carboplatin, 200 mg/m2 bolus on day 1; and ifosfamide, 2g/m2 for 3 consecutive days, infused over 2 hours. Mesna was administered as a bolus 15 minutes, and 4 and 8 hours after ifosfamide at 20% (intravenous [IV]), and 40% (orally, at home) of the ifosfamide dose, respectively.

RESULTS

Thirty-five patients (27 stage IVA and eight stage IVB) were considered eligible for response and toxicity evaluation. After a median of four cycles (maximum of six in responders), we observed objective responses in 21 patients (60%), with eight complete responses (CRs; 23%), including two histologically documented by laparotomy, and 13 (37%) partial responses (PRs) (95% confidence limits, 44% to 76%, 9% to 37%, and 21% to 53%, respectively). Median overall survival duration was 11 months (range, 3 to 24+). Median overall survival duration in the nonirradiated group was 17 months versus 4 months in the previously irradiated group (P = .005). The median progression-free survival duration of the responders was 12 months, and the median disease-free survival duration of the complete responders was 14 months. Toxicity was acceptable and included manageable alopecia, vomiting, and neutropenia. There was one toxic death due to febrile neutropenia and sepsis.

CONCLUSION

BIC can be administered on an outpatient basis and seems to be effective in inducing tumor response and palliation in patients with disseminated squamous cell carcinoma of cervix, with a possible survival benefit for previously nonirradiated patients, with an acceptable toxicity profile.

Modified therapy with 5-fluorouracil, doxorubicin, and methotrexate in advanced gastric cancer

BACKGROUND

In an attempt to decrease the toxic effects of fluorouracil, doxorubicin, and methotrexate (FAMTX) by reducing the dose of methotrexate from 1500 mg/m2, according to the original regimen, to 1000 mg/m2, the authors designed the modified FAMTX treatment that was evaluated in a prospective Phase II-III randomized trial.

METHODS

Patients with advanced gastric cancer were randomized to receive modified FAMTX treatment or supportive measures only (control group). In the middle of the study, the randomization was interrupted because of strong evidence of benefit in terms of tumor reduction and projected survival in the treatment arm receiving chemotherapy. By the end of the study, 30 assessable patients had received chemotherapy and 10 had received supportive treatment.

RESULTS

The overall response rate was 50% (15 patients); 12 patients (40%) had partial responses and 3 (10%) had complete responses (CR). One patient with extensive peritoneal carcinomatosis attained a CR pathologically documented by laparoscopic examination and peritoneal biopsy. The median overall survival time of the treated group was 9 months, whereas that of the control group was only 3 months (P = 0.001). The median overall survival time of the responders was 16 months, and their median remission duration was 8 months. The regimen was well tolerated, with a very acceptable toxicity profile. There was one toxic death resulting from neutropenia and sepsis in a patient who did not receive adequate leucovorin rescue.

CONCLUSIONS

This regimen appears to prolong survival in patients with advanced gastric cancer, and the reduction of the methotrexate dose does not seem to compromise its efficacy.

Modified therapy with 5-fluorouracil, doxorubicin, and methotrexate in advanced gastric cancer

BACKGROUND

In an attempt to decrease the toxic effects of fluorouracil, doxorubicin, and methotrexate (FAMTX) by reducing the dose of methotrexate from 1500 mg/m2, according to the original regimen, to 1000 mg/m2, the authors designed the modified FAMTX treatment that was evaluated in a prospective Phase II-III randomized trial.

METHODS

Patients with advanced gastric cancer were randomized to receive modified FAMTX treatment or supportive measures only (control group). In the middle of the study, the randomization was interrupted because of strong evidence of benefit in terms of tumor reduction and projected survival in the treatment arm receiving chemotherapy. By the end of the study, 30 assessable patients had received chemotherapy and 10 had received supportive treatment.

RESULTS

The overall response rate was 50% (15 patients); 12 patients (40%) had partial responses and 3 (10%) had complete responses (CR). One patient with extensive peritoneal carcinomatosis attained a CR pathologically documented by laparoscopic examination and peritoneal biopsy. The median overall survival time of the treated group was 9 months, whereas that of the control group was only 3 months (P = 0.001). The median overall survival time of the responders was 16 months, and their median remission duration was 8 months. The regimen was well tolerated, with a very acceptable toxicity profile. There was one toxic death resulting from neutropenia and sepsis in a patient who did not receive adequate leucovorin rescue.

CONCLUSIONS

This regimen appears to prolong survival in patients with advanced gastric cancer, and the reduction of the methotrexate dose does not seem to compromise its efficacy.

Modified therapy with 5-fluorouracil, doxorubicin, and methotrexate in advanced gastric cancer

BACKGROUND

In an attempt to decrease the toxic effects of fluorouracil, doxorubicin, and methotrexate (FAMTX) by reducing the dose of methotrexate from 1500 mg/m2, according to the original regimen, to 1000 mg/m2, the authors designed the modified FAMTX treatment that was evaluated in a prospective Phase II-III randomized trial.

METHODS

Patients with advanced gastric cancer were randomized to receive modified FAMTX treatment or supportive measures only (control group). In the middle of the study, the randomization was interrupted because of strong evidence of benefit in terms of tumor reduction and projected survival in the treatment arm receiving chemotherapy. By the end of the study, 30 assessable patients had received chemotherapy and 10 had received supportive treatment.

RESULTS

The overall response rate was 50% (15 patients); 12 patients (40%) had partial responses and 3 (10%) had complete responses (CR). One patient with extensive peritoneal carcinomatosis attained a CR pathologically documented by laparoscopic examination and peritoneal biopsy. The median overall survival time of the treated group was 9 months, whereas that of the control group was only 3 months (P = 0.001). The median overall survival time of the responders was 16 months, and their median remission duration was 8 months. The regimen was well tolerated, with a very acceptable toxicity profile. There was one toxic death resulting from neutropenia and sepsis in a patient who did not receive adequate leucovorin rescue.

CONCLUSIONS

This regimen appears to prolong survival in patients with advanced gastric cancer, and the reduction of the methotrexate dose does not seem to compromise its efficacy.

Modified therapy with 5-fluorouracil, doxorubicin, and methotrexate in advanced gastric cancer

BACKGROUND

In an attempt to decrease the toxic effects of fluorouracil, doxorubicin, and methotrexate (FAMTX) by reducing the dose of methotrexate from 1500 mg/m2, according to the original regimen, to 1000 mg/m2, the authors designed the modified FAMTX treatment that was evaluated in a prospective Phase II-III randomized trial.

METHODS

Patients with advanced gastric cancer were randomized to receive modified FAMTX treatment or supportive measures only (control group). In the middle of the study, the randomization was interrupted because of strong evidence of benefit in terms of tumor reduction and projected survival in the treatment arm receiving chemotherapy. By the end of the study, 30 assessable patients had received chemotherapy and 10 had received supportive treatment.

RESULTS

The overall response rate was 50% (15 patients); 12 patients (40%) had partial responses and 3 (10%) had complete responses (CR). One patient with extensive peritoneal carcinomatosis attained a CR pathologically documented by laparoscopic examination and peritoneal biopsy. The median overall survival time of the treated group was 9 months, whereas that of the control group was only 3 months (P = 0.001). The median overall survival time of the responders was 16 months, and their median remission duration was 8 months. The regimen was well tolerated, with a very acceptable toxicity profile. There was one toxic death resulting from neutropenia and sepsis in a patient who did not receive adequate leucovorin rescue.

CONCLUSIONS

This regimen appears to prolong survival in patients with advanced gastric cancer, and the reduction of the methotrexate dose does not seem to compromise its efficacy.

Chromosome aberrations in workers at a storage battery plant in Iraq

The present study deals with the determination of the incidence of chromosome changes in workers at a factory making storage batteries in Baghdad city. Blood samples were collected from 19 workers and 9 employees of the Scientific Research Council as control individuals, and chromosomes prepared from lymphocyte cultures were analyzed by standardized methods. Statistical analysis of the results gave significantly higher frequencies of chromatid and chromosome aberrations, particularly gaps, among the workers. No significant differences were observed in the incidence of chromosome aberrations in cells of smokers and non-smokers in both lead-exposed workers and controls. Therefore the observed increase in these aberrations was found to be associated mainly with exposure to lead oxides during the manufacture of the lead alloy grids and lead smelting.