Cancer stem cells in head and neck cancer: A Mini Review.

Head and neck cancer (HNC) is a multifaceted and genomically complex disease and rapidly emerging preclinical and clinical studies have provided a broader landscape of signaling. It is being realized that intra-tumor heterogeneity, genetic and epigenetic mutations considerably challenge wide ranging therapeutics and patients frequently develop locoregional recurrences, second primary tumours and distant metastases. Using high-throughput technologies, it has been revealed that existence of different subpopulations of cells within tumor mass with different phenotypic and functional properties with distinct tumour-initiating potential is responsible to HNC resistance. In light of accumulating evidence reported in recent years, it is now known that different intracellular proteins and cell surface markers have been used to study CSCs. This review provides an overview of CSC biomarkers in HNC treatment and their potential as therapeutic targets in improving the diagnosis, prognosis and treatment of HNC patients for new therapeutic strategies with information about estimation of prognosis and treatment decision. Further studies regarding biomarkers are necessary to determine the specific role of CSCs in HNC which could be useful in development of new therapeutic strategies to eliminate CSCs and maximize clinical outcome. Furthermore, CD44 still need more research in HNC once the studies show contradictions. Studies using lineage tracing and deep sequencing will provide a comprehensive understanding of CSC model and extent to which it is accountable for resistance against therapeutics and carcinogenesis.

A sex-linked SCAR marker in Bryonia dioica (Cucurbitaceae), a dioecious species with XY sex-determination and homomorphic sex chromosomes.

Genetic crosses between the dioecious Bryonia dioica (Cucurbitaceae) and the monoecious B. alba in 1903 provided the first clear evidence for Mendelian inheritance of dioecy and made B. dioica the first organism for which XY sex-determination was experimentally proven. Applying molecular tools to this system, we developed a sex-linked sequence-characterized amplified region (SCAR) marker for B. dioica and sequenced it for individuals representing the full geographic range of the species from Scotland to North Africa. For comparison, we also sequenced this marker for representatives of the dioecious B. cretica, B. multiflora and B. syriaca, and monoecious B. alba. In no case did any individual, male or female, yield more than two haplotypes. In northern Europe, we found strong linkage between our marker and sex, with all Y-sequences being identical to each other. In southern Europe, however, the linkage between our marker and sex was weak, with recombination detected within both the X- and the Y-homologues. Population genetic analyses suggest that the SCAR marker experienced different evolutionary pressures in northern and southern Europe. These findings fit with phylogenetic evidence that the XY system in Bryonia is labile and suggest that the genus may be a good system in which to study the early steps of sex chromosome evolution.

Effect of whole bone marrow cell infusion in the progression of experimental chronic renal failure.

INTRODUCTION: The therapeutic potential of adult stem cells for the treatment of chronic diseases is becoming increasingly evident over the last few years. In the present study, we sought to assess whether the infusion of bone marrow-derived mononuclear cells (MoSCs) and mesenchymal cells (MSCs) could reduce/stabilize the rate of progression of chronic renal failure (CRF) in rats. METHODS: We used the 5/6 renal mass reduction model to induce chronic renal failure in male Wistar rats. Renal function was assessed by measurements of serum creatinine (sCr), creatinine clearance (Clcr), and 24-hour proteinuria at baseline as well as 60 and 120 days after surgery. MoSCs and MSCs obtained from bone marrow aspirates were separated by the Ficoll-Hypaque method. After a 12- to 14-day culture, 1.5 x 10(6) MSCs and the same number of MoSCs were injected into the renal parenchyma of the remanant kidney of rats with CRF on the day of surgery. RESULTS: Among the control group, at day 120, the results were sCr = 1.31 +/- 0.5 mg/dL, Clcr = 0.64 +/- 0.35 mL/min, and proteinuria = 140.0 +/- 57.7 mg/24 h. Rats treated with MoSCs at day 120 had sCr = 0.81 +/- 0.20 mg/dL, Clcr = 1.05 +/- 0.26 mL/min, and proteinuria = 61 +/- 46.5 mg/24 h, while rats injected with MSCs had sCr = 0.95 +/- 0.1 mg/dL, Clcr = 0.68 +/- 0.24 mL/min, and proteinuria = 119.2 +/- 50.0 mg/24 h. Analysis of the progression to CRF showed that the treatment significantly reduced the rate of decline in Clcr after treatment with MoSc: control: -0.0049 +/- 0.0024 mL/min/d versus MSC: - 0.0013 +/- 0.0017 mL/min/d versus MoSC: +0.0002 +/- 0.0016 mL/min/d (P = .017). Proteinuria tended to be lower among the treated groups. Histological scores of chronic damage were not different, but distinct patterns of chronic lesions were observed among treated rats. CONCLUSION: Our results showed that progression of CRF in rats could be slowed/stabilized by intrarenal parenchymal injection of MoSCs. A trend toward reduction in the progression rate of CRF was also observed with injection of MSCs.

Glutamine synthetase, hemoglobin alpha-chain, and macrophage migration inhibitory factor binding to amyloid beta-protein: their identification in rat brain by a novel affinity chromatography and in Alzheimer's disease brain by immunoprecipitation.

Proteins binding to amyloid beta-protein (Abeta) may modulate the accumulation of Abeta in Alzheimer's disease (AD) brain. We developed a monomeric Abeta column for isolation of the proteins binding to Abeta from rat brain. By amino acid sequence analysis and immunoreactivity with specific antibodies, we identified three new Abeta-binding proteins, glutamine synthetase, hemoglobin alpha-chain, and macrophage migration inhibitory factor as well as serum albumin, beta-tubulin, and glyceraldehyde-3-phosphate dehydrogenase already identified as proteins bound to amyloid beta-protein precursor. In addition, the retained fraction contained both apolipoprotein E and alpha(1)-antichymotrypsin already known as Abeta binding proteins. Furthermore, we detected the complexes of these new binding proteins with Abeta in a soluble fraction of the cerebral cortex of AD brain by immunoprecipitation. Our results suggest that these binding proteins also associate with Abeta, leading to the clearance or the accumulation of Abeta and the neuronal cell damage in human brain.

Differential expression of beta amyloid protein precursor (APP) and tau mRNA in the aged human brain: individual variability and correlation between APP-751 and four-repeat tau.

We investigated the relationship between the differential expression of beta amyloid protein precursor (APP) and tau mRNA, and the extent of beta and tau deposition in three regions from each of the 38 aged brains obtained from consecutive autopsied cases. Remarkable variabilities were noted in the ratios of APP-770/-751/-695 and four-repeat tau among elderly individuals. There was no consistent alteration in the APP differential expression among beta plaque (-), (+), and (++(-) ) groups. Also, no differences in the four-repeat tau ratios were noted among tangle (-), (+), and (++) groups. Despite these great individual variabilities, APP-751 was found to be well-correlated with four-repeat tau. It is possible that APP-751 and four-repeat tau are increasing during aging, while APP-695 and three-repeat tau are decreasing.

High risk for unbalanced segregation of some reciprocal translocations: a large pedigree containing distal 4q trisomy from t(4;7)(q28;p22).

We report on a familial t(4;7)(q28;p22) with 2:2 adjacent-1 unbalanced segregation producing duplication of 4q28-->qter in multiple offspring. Within the large four-generation pedigree, a carrier had a reproductive outcome that was approximately equal for 1) the balanced translocation, 2) normal chromosomes, and 3) viable 4q trisomy or pregnancy loss. The three individuals with chromosomal confirmation of trisomy 4q28-->qter (comprising approximately 1.8% of the haploid autosomal length) had similar mental and developmental retardation, hypotonia, restricted speech, seizures, and facial anomalies but no cardiac, renal, or skeletal anomalies. It is suggested that these latter severe malformations, associated with the classic 4q2 to 3 group of anomalies, were from an imbalance outside 4q28-->qter and were not necessarily related to the relatively large size of the trisomic segment. Multiple different chromosomes are reported to be rearranged with 4q in the production of distal 4q trisomy. The incidence of 4q rearrangement remains unexplained, but once it is present in a family, viability of a large trisomy in 4q seems to explain the number of affected individuals reported.

Apolipoprotein E genotype, Alzheimer's pathologies and related gene expression in the aged population.

We have investigated the effect of genotypes of apolipoprotein E (ApoE) on the pathologies found in Alzheimer's disease (AD) and its related gene expression in 38 aged human brains obtained from consecutive autopsied cases. ApoE2/3, -3/3, -3/4, and -4/4 were typed in those aged brains, with ApoE3/3 being most prevalent. The AD pathologies were undetectable in ApoE2/3 brains, but were frequently observed in the other ApoE groups. In ApoE3/3 brains, 55%, 34%, and 24% of the cortical sections examined showed senile plaques (SPs), neurofibrillary tangles (NFTs), and cerebral amyloid angiopathy (CAA), respectively. In ApoE4/4 brains, the SP formation was significantly higher. The ApoE genotype neither affected ApoE, APP, or tau mRNA level, nor the differential expression of the latter two. These results suggest that ApoE4/4 accelerates and ApoE2/3 decelerates the development of the AD pathologies in the aged brain, but this is not through alterations of the APP and tau gene expression.

Phase II study of exatecan mesylate (DX-8951f) as first line therapy for advanced non-small cell lung cancer.

BACKGROUND: Exatecan mesylate (DX-8951f) is a water soluble analogue of camptothecin that inhibits topoisomerase I. This multi-centre phase II study evaluated the activity of single agent exatecan in previously untreated patients with advanced non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients with histologically or cytologically proven stage IIIb or IV NSCLC were treated with exatecan 0.5 mg/m(2) per day by 30 min intra-venous (i.v.) infusion for 5 days every 3 weeks to a maximum of six cycles. Measurable disease was documented prior to study entry and patients were re-staged every two cycles. Pharmacokinetic (PK) sampling was performed during cycle one. RESULTS: 39 patients (32 patients ECOG performance status 0 or 1; 29 male and ten female; mean age 63 years) were entered into the study. Thirty-three completed at least two cycles of exatecan and 11 completed six cycles. Two patients (5.1%, 95% C.I. 0.3-21.3%) had a partial response, 7 (18.0%) minor response and 8 (20.5%) stable disease. Median time to tumour progression (TTP) was 88 days and median overall survival 262 days. The main toxicity was reversible neutropenia. PK analysis of exatecan demonstrated a mean clearance of 2.28 l/h per m(2), volume of distribution 18.2 l/m(2) and mean elimination half-life of 7.9 h. CONCLUSIONS: Exatecan mesylate has limited activity in advanced NSCLC and is not recommended for further evaluation as a single agent in this tumour type. PK data from this trial supports results established in phase I studies.

Engineering of artificial cell-adhesive proteins by grafting EILDVPST sequence derived from fibronectin.

Fibronectin contains at least two distinct oligopeptide sequences serving as signals for the interaction with cell surface adhesion receptors termed integrins. One of these sequences, Arg-Gly-Asp-Ser (RGDS) tetrapeptide, was shown to be transferred to a truncated form of Staphylococcal IgG-binding protein (hereafter referred to as tSPA) with retention of its cell-adhesive activity [Maeda, T. et al. (1989) J. Biol. Chem. 264, 15165-15168]. We have extended the observation to another cell-adhesive sequence, Glu-Ile-Leu-Asp-Val-Pro-Ser-Thr (referred to as "CS1" sequence), to demonstrate that: i) the tSPA grafted with the sequence mediated adhesion of human lymphoma and rhabdomyosarcoma cells, mouse melanoma cells, but not of hamster fibroblasts; ii) antibodies against integrin alpha 4 and beta 1 subunits specifically inhibited cell adhesion mediated by the CS1-grafted tSPA; iii) a heterodivalent tSPA grafted with both RGDS and CS1 sequences at different sites was more potent in promoting cell adhesion than the monovalent tSPAs grafted with either sequence alone. These results indicate that not only the RGDS but also the CS1 sequence can be transferred to tSPA with retention of its cell-adhesive activity as well as its cell-type specificity, and that the grafted CS1 sequence is recognized by the same integrin isotype as the authentic sequence within intact fibronectin.

Complete amino acid sequence of rat kidney ornithine aminotransferase: identity with liver ornithine aminotransferase.

The complete amino acid sequence of rat kidney ornithine aminotransferase [EC 2.6.1.13] is presented. The 404-residue sequence was determined by analysis of peptides generated by digestion of the S-carboxyamidomethylated protein with CNBr, Achromobacter protease I, arginylendopeptidase, or Staphylococcus aureus V8 protease. Mueckler and Pitot have reported the amino acid sequence of the rat liver enzyme (440 residues) as predicted from the nucleotide sequence of the cDNA [Mueckler, M.M. & Pitot, H.C. (1985) J. Biol. Chem. 260, 12993-12997]. The amino acid sequence of the rat kidney enzyme presented herein coincides with residue 36 (Gly) through 440 (Phe) of the predicted precursor protein, indicating that the liver and kidney enzymes are identical, and that the enzyme is processed at the amino-terminal region after translation.

Improved method for expression of Kunitz-type serine proteinase inhibitor domain of beta-amyloid protein precursor in Escherichia coli and characterization of disulfide bonds of the product.

Kunitz-type serine proteinase inhibitor (KPI) domain of Alzheimer's disease-related beta-amyloid protein precursor (APP) was expressed in Escherichia coli as a fusion protein with a truncated form of Staphylococcus protein A. The fusion protein was purified from the cell culture medium using an IgG Sepharose column. The KPI domain was separated from the protein A portion by cleavage with human alpha-thrombin at the engineered recognition sequence, followed by purification on IgG Sepharose and reversed-phase HPLC columns. The recombinant KPI domain strongly inhibited trypsin; the inhibition constant (Ki) for bovine trypsin was 2.5 x 10(-11) M, comparable to those of the secreted forms of APP with the KPI domain. The recombinant protein contained three intramolecular disulfide bonds, which were determined to be located between Cys-6 (C1) and Cys-56 (C6), Cys-15 (C2) and Cys-39 (C4), and Cys-31 (C3) and Cys-52 (C5) of the recombinant KPI domain, respectively. These positions are highly homologous to those of disulfide bonds in bovine pancreatic trypsin inhibitor. The trypsin-inhibitory activity of the recombinant protein was abolished by preincubation with 0.4 mM dithiothreitol under non-denaturing conditions. By this mild reduction, all the disulfide bonds were completely cleaved. These results clearly indicate that the disulfide bonds play an important role in the function of the KPI domain of APP.

Artificial cell adhesive proteins engineered by grafting the Arg-Gly-Asp cell recognition signal: factors modulating the cell adhesive activity of the grafted signal.

An artificial cell adhesive protein could be engineered by grafting the RGDS tetrapeptide, the core sequence of the major cell adhesive site of fibronectin, to a truncated form of Staphylococcal protein A (tSPA) via cassette mutagenesis of the tSPA expression vector pRIT2T [T. Maeda et al. (1989) J. Biol. Chem. 264, 15165-15168]. We synthesized a panel of tSPA derivatives grafted with various RGDS-containing oligopeptides to address the problem of how the cell adhesive activity of the resulting tSPA derivatives was affected by the length and amino acid sequence of the grafted oligopeptides and by the sites on tSPA where the extra oligopeptides were inserted. The results showed that (i) the amino acid residues flanking the RGDS core sequence played a key role in modulating the cell adhesive activity of the grafted RGDS signal; (ii) at least two sites on tSPA, each corresponding to on e of the two HindIII sites of pRIT2T, were competent in sustaining the cell adhesive activity of the grafted signal; and (iii) the divalent tSPA containing the RGDS signal at both sites was more active than monovalent derivatives containing only one signal at either site. These results provide a strategic basis for engineering of artificial cell adhesive proteins by grafting the RGDS signal.

Amino acid sequence of a lectin from Japanese frog (Rana japonica) eggs.

The complete amino acid sequence and the location of disulfide bonds of a lectin from Japanese frog (Rana japonica) eggs, which specifically agglutinates transformed cells, are presented. The sequence was determined by analysis of peptides generated by digestion of the S-carboxyamidomethylated protein with Achromobacter protease I, or chymotrypsin, and by chemical cleavage with BNPS-skatole or cyanogen bromide. The lectin is a single-chain protein consisting of 111 residues, with a pyroglutamyl residue at the amino terminus. Four disulfide bonds link half-cystinyl residue 19 to 72, 34 to 82, 52 to 97, and 94 to 111. The sequence and the location of the disulfide bonds are highly homologous to those of bull frog (Rana catesbeiana) egg S-lectin. They are also homologous to human angiogenin, a tumor angiogenesis factor, and a family of pancreatic ribonucleases.

Cytogenetic findings in two basal cell carcinomas.

We describe the cytogenetic study of two basal cell carcinomas. Only single chromosomally abnormal clones could be detected in both. In addition, many nonclonal changes were seen in the samples, which may represent small neoplastic clones or the result of a basic molecular defect induced by carcinogens.

Phage typing of Salmonella enteritidis from different sources in Brazil.

The occurrence of Salmonella Enteritidis (SE) phage types (PTs) in samples collected from healthy and diseased chickens, in outbreaks of human gastroenteritis related to the consumption of egg products, in samples of poultry meat, in pipped embryos of broiler chickens, in meat meal, in poultry-rearing environments, and in many foods (cheese, mayonnaise, cake, and bacon) is described for strains isolated from 1995 to 1997 in Brazil. SE strains were isolated, and the most common PT was found to be PT 4, followed by PTs 7, 21, 35, 6, 4a, 8, 30, 6a, 5a, 1, and 1b. Fourteen strains were classified as react-but-do-not-conform strains, and one strain was not typeable. The results of this study demonstrate that PT 4 has a wider distribution among the sources studied than do any other SE phage types and is the most important phage type in human salmonellosis.

Characterization of the oxidized beta-Si3N4 whisker surface layer using XPS and TOF-SIMS.

The change in composition of the surface layer of beta-Si3N4 whiskers was examined after heat treatment in atmosphere. At 873 K, the beta-Si3N4 whisker was barely oxidized. At 1273 K, the oxidation of the surface layers of the whisker occurred easily. With the beta-Si3N4 oxidation, the Si-N bond gradually changed into the Si-N-O bond, and finally became the oxidized layer (amorphous layer) of the whisker surface. It was assumed that the whisker surface has a gradient interface structure which gradually changes from the oxide layer of the whisker's outer surface to the nitride crystal of the inside layer. It was confirmed that impurity elements such as Y and Ca existed mainly in the amorphous region near the interface between the amorphous layer and the crystal layer.

A unique early gastric tubular adenocarcinoma arising from a pre-existent carcinoid tumor in a patient with a more than 20-year history of type A gastritis: an immunohistochemical and ultrastructural study.

A unique early gastric tubular adenocarcinoma developed from a pre-existent carcinoid tumor in a patient with a more than 20-year history of type A gastritis, multiple endocrine cell micronests, hypergastrinemia, and a high level of serum antiparietal cell autoantibody. The patient was a 60-year-old Japanese man. The background gastric mucosa around the tumor showed marked atrophy with intestinal metaplasia, in which endocrine cell micronests were frequently observed, and was consistent with type A gastritis. The mass was composed of both adenocarcinoma and carcinoid tumor. The adenocarcinoma was restricted to the lamina mucosa and submucosal area, and constituted a minor component of the tumor mass. The carcinoid tumor was the dominant constituent of the tumor, that invaded continuously the subserosa and muscularis propria. Based on this examination together with the detailed immunohistochemical and ultrastructural studies, the adenocarcinoma was presumed to have developed from the pre-existent carcinoid tumor. Ultrastructurally there were no amphicrine cells in the tumor, containing both endocrine granules and mucin droplets.