ABSTRACT
In mammalian epidermis, the level of beta-catenin signaling regulates lineage selection by stem cell progeny. High levels of beta-catenin stimulate formation of hair follicles, whereas low levels favor differentiation into interfollicular epidermis and sebocytes. In transgenic mouse epidermis, overexpression of beta-catenin leads to formation of hair follicle tumors, whereas overexpression of N-terminally truncated Lef1, which blocks beta-catenin signaling, results in spontaneous sebaceous tumors. Accompanying overexpression of beta-catenin is up-regulation of Sonic hedgehog (SHH) and its receptor, Patched (PTCH/Ptch). In DeltaNLef1 tumors Ptch mRNA is up-regulated in the absence of SHH. We now show that PTCH is up-regulated in both human and mouse sebaceous tumors and is accompanied by overexpression of Indian hedgehog (IHH). In normal sebaceous glands IHH is expressed in differentiated sebocytes and the transcription factor GLI1 is activated in sebocyte progenitors, suggesting a paracrine signaling mechanism. PTCH1 and IHH are up-regulated during human sebocyte differentiation in vitro and inhibition of hedgehog signaling inhibits growth and stimulates differentiation. Overexpression of DeltaNLef1 up-regulates IHH and stimulates proliferation of undifferentiated sebocytes. We present a model of the interactions between beta-catenin and hedgehog signaling in the epidermis in which SHH promotes proliferation of progenitors of the hair lineages whereas IHH stimulates proliferation of sebocyte precursors.
Subject(s)
Cytoskeletal Proteins/metabolism , Sebaceous Gland Neoplasms/metabolism , Sebaceous Gland Neoplasms/pathology , Sebaceous Glands/cytology , Sebaceous Glands/metabolism , Trans-Activators/metabolism , Animals , Cell Differentiation , Cell Line , Hair Follicle/cytology , Hair Follicle/metabolism , Hedgehog Proteins , Humans , In Vitro Techniques , Intracellular Signaling Peptides and Proteins , Membrane Proteins/metabolism , Mice , Mice, Transgenic , Models, Biological , Patched Receptors , Patched-1 Receptor , Receptors, Cell Surface , Signal Transduction , Stem Cells/cytology , Stem Cells/metabolism , beta CateninABSTRACT
In this report we describe the identification of Krüppel-like factor 5 (KLF5/BTEB2) in a yeast one-hybrid screen using a keratinocyte-specific, NF-kappaB binding site as bait. The KLF5 cDNA encodes a larger protein of 457 aa rather than the earlier reported protein of 209 aa. The full-length KLF5 functions as a transactivator in HepG2 cells, and the stimulation of cells with 12-0-tetradecanoylphorbol-13-acetate (TPA) can modulate its transcriptional activity. Overexpression of KLF5 leads to an increase in the TPA response from VLTRE, a TPA-inducible enhancer element that shows keratinocyte specificity with respect to Rel/NF-kappaB binding. The KLF5-mediated transcriptional increase is not observed in the presence of overexpressed NF-kappaB inhibitor, IkappaBalpha. Cotransfection of KLF5 and the p65 subunit of NF-kappaB, results in a synergistic transactivation of the VLTRE-luciferase reporter. The KLF5 mRNA and the protein is expressed in keratinocytes and throughout the adult human epidermis. Its expression is especially strong in the matrix and the inner root sheath cuticle layer of the hair follicle, sebaceous glands and sweat glands. Considering the TPA-responsiveness and expression pattern, we propose that KLF5 like another member of its family KLF4/GKLF may play an important role in skin morphogenesis and carcinogenesis potentially via its interaction with NF-kappaB factors.
Subject(s)
Hair Follicle/metabolism , NF-kappa B/metabolism , Skin/metabolism , Trans-Activators/metabolism , Animals , Binding Sites/genetics , Cells, Cultured , Clone Cells/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Gene Expression/genetics , Genes, Reporter/drug effects , Genes, Reporter/genetics , Hair Follicle/cytology , Hair Follicle/growth & development , Humans , Immunohistochemistry , Kruppel-Like Factor 4 , Kruppel-Like Transcription Factors , Mice , NF-kappa B/genetics , Pyridines/pharmacology , RNA, Messenger/metabolism , Skin/cytology , Skin/growth & development , Trans-Activators/geneticsABSTRACT
It is widely accepted that disruption of the hedgehog-patched pathway is a key event in development of basal cell cancer. In addition to patched gene alterations, p53 gene mutations are also frequent in basal cell cancer. We determined loss of heterozygosity in the patched and p53 loci as well as sequencing the p53 gene in tumors both from sporadic and hereditary cases. A total of 70 microdissected samples from tumor and adjacent skin were subjected to PCR followed by fragment analysis and DNA sequencing. We found allelic loss in the patched locus in 6/8 sporadic basal cell cancer and 17/19 hereditary tumors. All sporadic and 7/20 hereditary tumors showed p53 gene mutations. Loss of heterozygosity in the p53 locus was rare in both groups. The p53 mutations detected in hereditary tumors included rare single nucleotide deletions and unusual double-base substitutions compared to the typical ultraviolet light induced missense mutations found in sporadic tumors. Careful microdissection of individual tumors revealed genetically linked subclones with different p53 and/or patched genotype providing an insight on time sequence of genetic events. The high frequency and co-existence of genetic alterations in the patched and p53 genes suggest that both these genes are important in the development of basal cell cancer.
Subject(s)
Basal Cell Nevus Syndrome/genetics , Membrane Proteins/genetics , Mutation/genetics , Neoplasms, Basal Cell/genetics , Tumor Suppressor Protein p53/genetics , Adult , Aged , Aged, 80 and over , Basal Cell Nevus Syndrome/pathology , Female , Humans , Immunohistochemistry , In Situ Hybridization , Loss of Heterozygosity/genetics , Male , Middle Aged , Mutation, Missense/genetics , Neoplasms, Basal Cell/pathology , Patched Receptors , Polymerase Chain Reaction , RNA, Messenger/analysis , RNA, Messenger/genetics , RNA, Neoplasm/analysis , RNA, Neoplasm/genetics , Receptors, Cell SurfaceABSTRACT
BACKGROUND: Self-rating of health is among the most frequently assessed health perceptions in epidemiological research. The aim of this study was to compare different measures of global self-rated health (SRH) with respect to differences in age and sex groups and relations to hypothesized determinants. METHOD: Three single-question measures of SRH were included in a health questionnaire administered to 8200 randomly chosen men and women. Two SRH measures were non-comparative, one with seven (SRH-7) and one with five response options (SRH-5), while the third measure included a comparison with others of the same age (SRH-age). SRH-7 had specified response options only at the ends of the scale, while the other two measures gave specified statements for each option. Comparisons between the SRH assessments were studied with respect to response frequencies, frequency distributions, age and gender differences and differences in associations with hypothesized determinants. RESULTS: The differences between the SRH measures were in most cases marginal. Some diversities may, however, be worth considering: a high drop-out rate for the SRH-7 measure in the oldest age group; a trend that SRH-7 correlated most strongly with the independent variables; SRH-age showed improved health ratings with increasing age but a less skewed frequency distribution compared to the non-comparative measures. CONCLUSIONS: The results imply that non-comparative measures are more appropriate in longitudinal studies and that measures without specified response options might be less suitable for an older study group. The overall impression is, however, that the different measures represents parallel assessments of subjective health.
Subject(s)
Health Surveys , Self-Assessment , Surveys and Questionnaires , Adolescent , Adult , Age Factors , Aged , Female , Humans , Male , Middle Aged , Multivariate Analysis , Regression Analysis , Sex Factors , Socioeconomic FactorsABSTRACT
OBJECTIVES: The purpose of this study was to evaluate the relationship of self-rated health to a measure of physical status, based on a professional rating of the individual's health from a strictly physical point of view. METHODS: A random selection of 407 people over the age of 20 from the north-western catchment area of greater Stockholm were invited in 1995 to a physical examination, including a self-report questionnaire with questions about self-rated health, lifestyle, psychosocial factors and quality of life. A measure of physical health on a 5-point graded scale was constructed using the information from the records of the physical examination as a base. RESULTS: Self-rated health and the professional ratings of health coincided in approximately 60% of the cases. There were a relatively large number of cases where the ratings were contradictory. The correlation between the scales was 0.45. Comparison between the two ratings with respect to association with potential determinants showed that physical factors naturally explained most of the variances in physical health, whereas social and mental well-being and somatic conditions (women) were the most important explanatory variables for self-rated health. Irrespective of whether they had "favourable" or "unfavourable" health, those with "poor" self-rated health also had perceived lower social and mental well-being, less appreciation, more somatic conditions (women) and worse coping abilities (men). CONCLUSIONS: With mental, psychosocial and social problems becoming more pronounced in sickness patterns for primary care patients, self-rated health could be a helpful device, especially when time resources for consultations are short. This measure could also give a more global view of the patient's situation when effectivity and rationality can be a threat to a holistic view of the patient.
Subject(s)
Clinical Competence , Health Status , Patient Satisfaction , Self-Assessment , Adult , Female , Humans , Male , Middle Aged , Patient Acceptance of Health Care/psychology , Psychology , Quality of Life , Regression Analysis , Surveys and QuestionnairesABSTRACT
Basal cell carcinoma is the most prevalent cancer in the western world, showing a rapid increase in incidence. Activation of the Sonic hedgehog/Patched (PTCH) signaling pathway because of PTCH1 inactivation is a key event in sporadic and familial basal cell carcinoma development in humans and is associated with transcriptional activation of specific target genes, including PTCH1 itself. These changes are analogous to the situation in Drosophila where hedgehog activates the zinc-finger transcription factor Cubitus interruptus, leading to increased transcription of target genes. In the present study, we show that mice ectopically expressing the human Cubitus interruptus homolog GLI-1 in the skin develop tumors closely resembling human BCCs as well as other hair follicle-derived neoplasias, such as trichoepitheliomas, cylindromas, and trichoblastomas. Furthermore, examination of the tumors revealed wild-type p53 and Ha ras genes. These findings firmly establish that increased GLI-1 expression is central and probably sufficient for tumor development and suggest that GLI-1-induced tumor development does not depend on additional p53 or Ha ras mutations.
Subject(s)
Carcinoma, Basal Cell/genetics , Skin Neoplasms/genetics , Transcription Factors/genetics , Animals , Base Sequence , DNA Primers , Genes, p53 , Genes, ras , Humans , Kruppel-Like Transcription Factors , Mice , Mice, Transgenic , Skin/metabolism , Zinc Finger Protein GLI1ABSTRACT
The alkylation of cysteine residue by different classes of carbonium ions, derived from the cleavage of side chain protective groups in anhydrous HF, was investigated. It was found that side chain protection as beta-2,4-dimethylpent-3-yl ester (Dmp) or 2,4-dimethylpent-3-yloxycarbonyl (Doc) groups resulted in more than seven-fold lower level of alkylated byproducts. This makes Dmp and Doc protection of amino acid side chain during solid phase synthesis particularly valuable in the synthesis of peptides containing cysteine residues or other functional groups prone to alkylation by carbonium ions.
Subject(s)
Biochemistry/methods , Peptides/chemical synthesis , Alkylation , Aspartic Acid/chemistry , Cations , Chromatography, High Pressure Liquid , Cysteine/chemistryABSTRACT
Sonic hedgehog, Patched and Gli are components of a mammalian signalling pathway that has been conserved during evolution and which has a central role in the control of pattern formation and cellular proliferation during development. Here we identify the human Suppressor-of-Fused (SUFUH) complementary DNA and show that the gene product interacts physically with the transcriptional effector GLI-1, can sequester GLI-1 in the cytoplasm, but can also interact with GLI-1 on DNA. Functionally, SUFUH inhibits transcriptional activation by GLI-1, as well as osteogenic differentiation in response to signalling from Sonic hedgehog. Localization of GLI-1 is influenced by the presence of a nuclear-export signal, and GLI-1 becomes constitutively nuclear when this signal is mutated or nuclear export is inhibited. These results show that SUFUH is a conserved negative regulator of GLI-1 signalling that may affect nuclear-cytoplasmic shuttling of GLI-1 or the activity of GLI-1 in the nucleus and thereby modulate cellular responses.
Subject(s)
Cell Nucleus/metabolism , Drosophila Proteins , Oncogene Proteins/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Transcription Factors/metabolism , Transcription, Genetic , Adult , Amino Acid Sequence , Animals , Cell Differentiation , Cell Line , Chickens , Cytoplasm/metabolism , Drosophila melanogaster/genetics , Embryo, Mammalian , Embryo, Nonmammalian , Gene Expression Regulation, Developmental , Humans , Mammals , Mice , Molecular Sequence Data , Osteoblasts/metabolism , Osteogenesis , Recombinant Proteins/metabolism , Repressor Proteins/chemistry , Sequence Alignment , Sequence Homology, Amino Acid , Trans-Activators , Transfection , Zinc Finger Protein GLI1ABSTRACT
AIMS: Cardiac rehabilitation including exercise training is of proven value in ischaemic heart disease. However, elderly patients frequently are not encouraged to participate in such programmes. This study evaluates the physiological effects and self-reported quality of life after an aerobic outpatient group-training programme in subjects above the age of 65 years. METHODS AND RESULTS: A consecutive series of 101 patients (males 80%) aged 65-84 (mean 71) years recovering from an acute coronary event were randomized to either a supervised out patient group-training programme (n=50) or to a control group (n=51). The two groups were well balanced as regards clinical characteristics. The compliance in the training group was 87%. Exercise tolerance increased in the trained group from 104 to 122 and 111 W after 3 and 12 months respectively. The corresponding values were 102, 105 and 105 W among controls. Parameters, such as quality of life, self-estimated level of physical activity, fitness and well-being were graded higher by the trained patients than those who served as controls on the two occasions of follow-up. CONCLUSIONS: Aerobic group-training of elderly patients recovering from an acute coronary event beneficially influences physical fitness and several parameters expressing quality of life. Great care has to be taken to preserve the initial effects by continued training.
Subject(s)
Angina, Unstable/rehabilitation , Exercise Therapy/methods , Myocardial Infarction/rehabilitation , Physical Fitness , Quality of Life , Aged , Aged, 80 and over , Angina, Unstable/surgery , Coronary Artery Bypass , Exercise Tolerance , Female , Follow-Up Studies , Humans , Male , Myocardial Infarction/surgery , Outpatients , Treatment OutcomeABSTRACT
By a combination of cDNA library screening, rapid amplification of cDNA ends analysis, and BAC sequencing, a novel human patched-like gene (PTCH2) has been cloned and sequenced. The genomic organization is similar to PTCH1 with 22 exons and, by radiation hybrid mapping, PTCH2 has been localized to chromosome 1p33-34, a region often lost in a variety of tumors. Several alternatively spliced mRNA forms of PTCH2 were identified, including transcripts lacking segments thought to be involved in sonic hedgehog binding and mRNAs with differentially defined 3' terminal exons. In situ hybridization revealed high expression of PTCH2 transcripts in both familial and sporadic basal cell carcinomas in similarity to what has been observed for PTCH1, suggesting a negative regulation of PTCH2 by PTCH1. This finding tightly links PTCH2 with the sonic hedgehog/PTCH signaling pathway, implying that PTCH2 has related, but yet distinct, functions than PTCH1.
Subject(s)
Alternative Splicing , Carcinoma, Basal Cell/genetics , Membrane Proteins/genetics , Amino Acid Sequence , Base Sequence , Chromosome Mapping , Humans , Molecular Sequence Data , Patched Receptors , Patched-1 Receptor , Patched-2 Receptor , Receptors, Cell Surface , Up-RegulationABSTRACT
The authors examined Type A behavior pattern, which has been investigated primarily as a risk factor for coronary heart disease, as a risk factor for car accidents and near accidents. Type A behavior pattern, which is characterized by excessive impatience, competitiveness, hostility, and time pressure, was assessed by means of the Videotaped Structured Interview. One hundred thirty-five Swedish car drivers (66 men and 69 women) were studied: 78 Type A and 58 Type B (that is, not having, Type A behavior). Time pressure was significantly associated with near accidents when age, sex, annual mileage, and urban driving were controlled in a multivariate model.
Subject(s)
Accidents, Traffic/psychology , Type A Personality , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Personality Assessment , Risk Factors , Sweden , Time PerceptionABSTRACT
This study examines the extent to which people forego seeking primary health care due to the cost and to investigate the associated demographic, physical, psychological and social factors. In 1995, questionnaires were sent to a random sample of the population in two healthcare regions in the Stockholm area in Sweden covering a total of about 400,000 inhabitants. Among the sample of 8200 people over the age of 17 yr, 69% replied to the questionnaire. About 22% stated that on one or more occasions during the past year they had foregone seeking care due to the cost. About 30% stated that they had foregone or hesitated seeking medical help due to the cost during the past year. This applied to women to a greater extent than men. Not seeking medical care was strongly correlated to a self-assessment of personal finances. Among those who described their financial situation as poor, more than half stated that, on at least one occasion, they had foregone seeking medical care due to the cost. As a consequence, weaker groups in society such as the unemployed, students, foreign nationals and single mothers were overrepresented in this group. Those who had foregone care perceive their health as worse and they had a greater degree of general pains and a higher occurrence of chronic disease/disability compared to those who had not foregone care. Between 1970 and 1995, patient charges for consulting a general practitioner within Stockholm County have increased more than three times faster than the consumer price index. The results suggest that the rapidly increasing patient charges particularly affect the weaker social groups and thus pose a threat to the aim of Swedish healthcare legislation--that good care should be available to everyone on equal terms.
Subject(s)
Health Care Costs , Patient Acceptance of Health Care/statistics & numerical data , Primary Health Care/statistics & numerical data , Adolescent , Adult , Aged , Confidence Intervals , Female , Health Services Needs and Demand/economics , Health Status , Humans , Logistic Models , Male , Medically Uninsured , Middle Aged , Odds Ratio , Poverty , Primary Health Care/economics , Surveys and Questionnaires , SwedenABSTRACT
The human homologue of Drosophila patched (PTCH), located at chromosome 9q22.3, was recently identified as a candidate tumor suppressor gene for familial and sporadic basal cell carcinomas. Squamous cell carcinomas (SCCs) of the skin display allelic loss in this chromosomal region, which, in addition to the PTCH gene, contains the DNA repair gene xeroderma pigmentosum complementation group A (XPA). Patients with xeroderma pigmentosum are predisposed to non-melanoma skin tumors because of deficient excision repair of ultraviolet-induced DNA damage. Mutation analysis by single-strand conformation analysis and direct DNA sequencing of all 23 exons of the PTCH gene and all six exons of the XPA gene in 14 SCCs did not reveal structural alterations in any of these genes. Additionally, analysis of PTCH expression by in situ hybridization in SCCs revealed no evidence of upregulation of PTCH mRNA, confirming the lack of mutations in this gene. These findings suggest that another, yet to be identified gene or genes on chromosome 9q are involved in SCC tumorigenesis.
Subject(s)
Carcinoma, Squamous Cell/genetics , DNA-Binding Proteins/genetics , Membrane Proteins/genetics , Neoplasm Proteins/genetics , Skin Neoplasms/genetics , Chromosomes, Human, Pair 9 , DNA Mutational Analysis , Humans , In Situ Hybridization , Loss of Heterozygosity , Patched Receptors , Patched-1 Receptor , Polymorphism, Genetic , Polymorphism, Single-Stranded Conformational , RNA, Messenger/genetics , RNA, Neoplasm/genetics , Receptors, Cell Surface , Xeroderma Pigmentosum Group A ProteinABSTRACT
This study evaluates the effects of an intervention on hostility and time pressure in primary health care patients. A total of 47 men and women were studied, of whom 22 participated in an intervention program and 25 were controls. The intervention group changed global Type A behavior, hostility and time pressure significantly more than the control group and this change was stable up to 2 years following the study. Men altered their behavior significantly more than women.
Subject(s)
Family Practice , Hostility , Psychotherapy/methods , Stress, Psychological/rehabilitation , Type A Personality , Adult , Coronary Disease/prevention & control , Coronary Disease/psychology , Female , Humans , Male , Middle Aged , Sex Factors , Stress, Psychological/psychology , Sweden , TimeABSTRACT
The nevoid basal cell carcinoma (Gorlin) syndrome (NBCCS) is an autosomal dominant disorder characterized by multiple developmental defects and cancer susceptibility. NBCCS is caused by mutations in the human homologue (PTCH) of the Drosophila patched gene, a developmental regulator implicated in signaling of hedgehog and smoothened. The PTCH gene was found to contain somatic mutations also in sporadic basal cell carcinomas and medulloblastomas, tumors seen in NBCCS, consistent with PTCH acting as a tumor suppressor. Because basal cell carcinomas have been observed to develop in association with benign trichoepitheliomas (TEs) in the same lesions, patients, and families and may share the same cell of origin, we have analyzed PTCH for mutations and expression in TEs. We report frameshift and in-frame somatic deletions in this gene and a consistent overexpression of PTCH mRNA in TEs. These findings provide the first evidence of a gene mutation in TEs and identify a common pathogenic pathway for histopathologically similar but prognostically distinct skin tumors. Moreover, these results support the presence of a gatekeeper mechanism in multistep skin tumorigenesis exerted by the altered PTCH signaling pathway.
Subject(s)
Carcinoma, Basal Cell/genetics , Genes, Neoplasm/genetics , Genes, Tumor Suppressor/genetics , Mutation , Neoplasm Proteins/genetics , Skin Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Carcinoma, Basal Cell/metabolism , Female , Germ-Line Mutation , Humans , Male , Middle Aged , Neoplasm Proteins/metabolism , Skin Neoplasms/metabolismABSTRACT
Recently, a human homologue of the Drosophila patched gene, PTCH, was identified as a putative tumor suppressor mutated in both hereditary and sporadic basal cell carcinomas. Because PTCH controls its own transcription, inactivating mutations in PTCH may lead to overexpression of mutant PTCH mRNA due to loss of autoregulation. The present study is aimed at evaluating whether deregulation of PTCH mRNA expression is a general feature of BCCs of varying histological growth pattern and malignant potential. Irrespective of histological subtype, PTCH mRNA was overexpressed consistently as determined by in situ hybridization in all of the sporadic (n = 16) and hereditary (n = 20) tumors examined. PTCH expression was found in all of the tumor cells but appeared stronger in the peripheral palisading cells. PTCH mRNA was not detected in adjacent nontumor epidermal cells or in other parts of the epidermis. In the majority of tumors (20 of 36), nuclear immunostaining for p53 was found in scattered cells, whereas seven tumors completely lacked p53 immunoreactivity. Our finding of an up-regulation of PTCH mRNA levels in all of the BCCs analyzed indicates that deregulation of the PTCH signaling pathway constitutes an early rate-limiting event in BCC development.
Subject(s)
Carcinoma, Basal Cell/metabolism , Drosophila Proteins , Insect Proteins/metabolism , Membrane Proteins/metabolism , Skin Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Carcinoma, Basal Cell/genetics , Female , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , In Situ Hybridization , Male , Middle Aged , RNA, Messenger/metabolism , Receptors, Cell Surface , Skin Neoplasms/genetics , Tumor Suppressor Protein p53/metabolismABSTRACT
OBJECTIVE: To develop a short and easily used self-report measure of Type A behaviour (Simplified Type A Questionnaire = STAQ) and to examine its capacity to predict Type A behaviour as assessed by more time-consuming measures. DESIGN: A Videotaped Structured Interview (VSI) and a self-report measure, previously validated in Sweden, were used as comparison instruments to the STAQ. SETTING: Primary health care. PATIENTS: 206 (81 men and 125 women) aged 17-75 years attending a health centre during one year. MAIN OUTCOME MEASURES: The reliability, measured by Cronbach's alpha and split-half correlation. The specificity and sensitivity of the STAQ. The correlaiton between the STAQ and the two other diagnostic measures. RESULTS: The reliability of the STAQ was 0.70 and 0.75, respectively. The specificity was 83% and the sensitivity 75%. The correlation between the STAQ and the VSI was 0.45. The correlation between the STAQ and the previously validated self-report was 0.61. CONCLUSIONS: The STAQ has good psychometric properties and, in comparison with other diagnostic measurement instruments in medical service, it has an acceptable discrimination capacity.
Subject(s)
Personality Tests , Self-Assessment , Type A Personality , Adolescent , Adult , Aged , Coronary Disease/psychology , Data Interpretation, Statistical , Female , Humans , Interview, Psychological , Male , Middle Aged , Predictive Value of Tests , PsychometricsABSTRACT
Nine new analogues of substance P (SP) were designed using quantitative sequence-activity models based on the amino acid z-scales with PLS as the statistical method and the GOLPE procedure for variable selection. The nine SP analogues were synthesised by solid-phase peptide synthesis and tested for affinity to the NK-1 receptor from rat brain with radio receptor assay using [125I]-Bolton-Hunter substance P as labelled ligand. All of the new substance P analogues showed high affinities, with IC50 values of less than 0.8 nM. One analog, Lys-Arg-Ala-Lys-Phe-Met-Met-Phe-Phe-Gly-Leu-Let-NH2, showed a exceptional high affinity for the NK1 receptor, with IC50 = 5 pM.
Subject(s)
Models, Molecular , Peptides/chemistry , Substance P/analogs & derivatives , Animals , Peptides/metabolism , Rats , Receptors, Neurokinin-1/metabolism , Structure-Activity Relationship , Substance P/chemistry , Substance P/metabolismABSTRACT
The nevoid basal cell carcinoma syndrome is an autosomal dominant disorder, characterized by predisposition to multiple early basal cell carcinomas of the skin and several other tumours as well as frequent occurrence of developmental anomalies. The gene has previously been mapped to chromosome 9q22 and is believed to function as a tumour suppressor. We have applied linkage and haplotype analysis to four Swedish nevoid basal cell carcinoma syndrome families to refine the localization of the nevoid basal cell carcinoma syndrome gene. Information from critical recombinants localizes the gene proximal of marker D9S287, which in combination with analysis of loss of heterozygosity in a hereditary cardiac fibroma has allowed us to define a minimal candidate region of 1Mb or less for the nevoid basal cell carcinoma gene flanked by the markers D9S280 and D9S287 in the 9q22.3 area.