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P J Goodfellow

Publications and source records attributed to P J Goodfellow.

At least 55 records · Page 3Linked to original sources

RET gene and its implications for cancer.

The RET proto-oncogene encodes a protein receptor tyrosine kinase. RET mutations are associated with the dominantly inherited cancer syndromes multiple endocrine neoplasia (MEN) types 2A and 2B and familial medullary thyroid carcinoma (FMTC). In MEN 2A, MEN 2B, and FMTC, direct detection of RET mutations can be used to identify disease allele carriers prior to the development of clinically evident neoplasms. RET mutations are also associated with sporadic thyroid carcinomas. The effects of RET mutation on protein function have been investigated both in vivo and in vitro, and the study of RET has served to provide insights into the mechanisms of tumorigenesis in general.

Alleles↗

Allelic loss of sequences from the long arm of chromosome 10 and replication errors in endometrial cancers.

Thirty-seven endometrial cancers were subjected to an allelotype analysis in an attempt to identify chromosomal regions that are lost in a significant portion of tumors and to identify tumors characterized by replication errors. Thirty-nine highly polymorphic microsatellite markers representing all chromosomal arms, excluding the X and the short arms of the acrocentrics, were examined. An average of 20 informative cases were evaluated for each marker. Genetic alterations were detected in 30 of the 37 tumors. Replication errors were identified in 8 tumor specimens. Loss of heterozygosity was observed for loci on all chromosomes examined with the exception of chromosomes 4 and 20. The two most frequent sites of loss were at the marker loci examined on 10q (40%) and 17p (29%). Six additional simple sequence repeat markers from 10q were genotyped in an effort to refine the region of 10q loss. The chromosome 10 markers used in these studies were physically mapped with the use of a panel of somatic hybrids that retain defined portions of chromosome 10. The observed patterns of loss of sequences on 10q suggest a role for a tumor suppressor gene in the 10q23-26 region in the development or progression of endometrial cancers.

Alleles↗

Frequent mutations of CDKN2 in primary pancreatic adenocarcinomas.

The gene encoding the cell-cycle regulatory protein p16, CDKN2, is localized on chromosome band 9p21. CDKN2 is frequently deleted or mutated in a variety of tumor cell lines, including pancreatic cancer cell lines and xenografts, as well as in some primary tumors. We examined 32 primary pancreatic adenocarcinomas for CDKN2 mutations and for loss of heterozygosity of 9p21 sequences to assess the role of CDKN2 in pancreatic carcinogenesis. Single-strand conformation variant analysis (SSCV) and direct sequencing of the variants revealed somatic CDKN2 mutations in 11 of 32 tumors (five frame-shift mutations, five nonsense mutations, and one missense mutation). One tumor appeared to be characterized by homozygous deletion of CDKN2. These results suggest that CDKN2 plays an important role during tumorigenesis or tumor progression in a significant proportion of pancreatic adenocarcinomas.

Adenocarcinoma↗

Low frequency of CDKN2 mutation in endometrial carcinomas.

The CDKN2 gene on chromosome 9p21 encodes the p16 inhibitor of cyclin D/cyclin-dependent kinase 4 complexes. Mutations and deletions of CDKN2 have been frequently identified in cell lines, whereas most primary tumors have demonstrated a lower frequency of alteration. To assess the role of CDKN2 in endometrial tumorigenesis, 34 tumor samples were examined for loss of heterozygosity at 9p21 and mutation in CDKN2. To identify tumors that had lost 9p21, samples were genotyped with markers flanking the CDKN2 locus. The frequency of CDKN2 mutation in endometrial carcinomas was determined by single-strand conformation variant analysis and direct sequencing of variants. Of the 34 tumors examined, three revealed loss of 9p21 sequences. Two samples were characterized by point mutations in CDKN2, one of which also showed loss of 9p21 sequences.

Alleles↗

Phylogenetic conservation and physical mapping of members of the H6 homeobox gene family.

Homeobox genes represent a class of transcription factors that play key roles in the regulation of embryogenesis and development. Here we report the identification of a homeobox-containing gene family that is highly conserved at both the nucleotide and amino acid levels in a diverse number of species. These species encompass both vertebrate and invertebrate phylogenies, ranging from Homo sapiens to Drosophila melanogaster. In humans, at least two homeobox sequences from this family were identified representing a previously reported member of this family as well as a novel homeobox sequence that we physically mapped to the 10q25.2-q26.3 region of human Chromosome (Chr) 10. Multiple members of this family were also detected in three additional vertebrate species including Equus caballus (horse), Gallus gallus (Chicken), and Mus musculus (mouse), whereas only single members were detected in Tripneustes gratilla (sea urchin), Petromyzon marinus (lamprey), Salmo salar (salmon), Ovis aries (sheep), and D. melanogaster (fruit fly).

Amino Acid Sequence↗

Assignment of a second Charcot-Marie-Tooth type II locus to chromosome 3q.

Charcot-Marie-Tooth disease (CMT) is the most common inherited motor and sensory neuropathy. The neuronal form of this disorder is referred to as Charcot-Marie-Tooth type II disease (CMT2). CMT2 is usually inherited as an autosomal dominant trait with a variable age at onset of symptoms associated with progressive axonal neuropathy. In some families, the locus that predisposes to CMT2 has been demonstrated to map to the distal portion of the short arm of chromosome 1. Other families with CMT2 do not show linkage with 1p markers, suggesting genetic heterogeneity in CMT2. We investigated linkage in a single large kindred with autosomal dominant CMT2. The gene responsible for CMT2 in this kindred (CMT2B) was mapped to the interval between the microsatellite markers D3S1769 and D3S1744 in the 3q13-22 region. Study of additional CMT2 kindreds should serve to further refine the disease gene region and may ultimately lead to the identification of a gene defect that underlies the CMT2 phenotype.

Charcot-Marie-Tooth Disease↗

Genetic analysis of kifafa, a complex familial seizure disorder.

Kifafa is the Swahili name for an epileptic seizure disorder, first reported in the early 1960s, that is prevalent in the Wapogoro tribe of the Mahenge region of Tanzania in eastern Africa. A 1990 epidemiological survey of seizure disorders in this region reported a prevalence in the range of 19/1,000-36/1,000, with a mean age at onset of 11.6 years; 80% of those affected had onset prior to 20 years of age. A team of investigators returned to Tanzania in 1992 and collected data on > 1,600 relatives of 26 probands in 20 kifafa families. We have undertaken a genetic analysis of these data in order to detect the presence of familial clustering and whether such aggregation could be attributed to genetic factors. Of the 127 affected individuals in these pedigrees, 23 are first-degree relatives (parent, full sibling, or offspring) of the 26 probands; 20 are second-degree relatives (half-sibling, grandparent, uncle, or aunt). When corrected for age, the risk to first-degree relatives is .15; the risk to second-degree relatives is .063. These risks are significantly higher than would be expected if there were no familial clustering. Segregation analysis, using PAP (rev.4.0), was undertaken to clarify the mode of inheritance. Among the Mendelian single-locus models, an additive model was favored over either a dominant, recessive, or codominant model. The single-locus model could be rejected when compared with the mixed Mendelian model (inclusion of a polygenic background), although the major-gene component tends to be recessive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Single missense mutation in the tyrosine kinase catalytic domain of the RET protooncogene is associated with multiple endocrine neoplasia type 2B.

Multiple endocrine neoplasia type 2B (MEN 2B) is a human cancer syndrome characterized by medullary thyroid carcinoma (MTC), pheochromocytomas, mucosal neuromas, ganglioneuromas of the intestinal tract, and skeletal and ophthalmic abnormalities. It appears both as an inherited disorder and as de novo disease. Sequence analysis of germ-line DNA from MEN 2B patients revealed the existence of the same point mutation in the RET protooncogene in 34 unrelated individuals. This sequence difference was not observed in 93 unaffected individuals, including the normal parents of 14 de novo MEN 2B patients. The mutation (ATG-->ACG) results in the replacement of methionine with threonine within the catalytic core region of the tyrosine kinase domain. We propose that this amino acid replacement effects substrate interactions and results in dominant oncogenic activity by the RET protein. Missense mutations in the extracellular ligand-binding domain of the RET protooncogene previously have been associated with two other disorders [MEN 2A and familial MTC (FMTC)] in which MTC is observed. MEN 2B represents the third form of heritable MTC known to be an allele of RET. Alterations in two different functional domains of the putative receptor protein tyrosine kinase are implicated in development of MTC.

Alleles↗

Linkage analysis of X-linked cleft palate and ankyloglossia in Manitoba Mennonite and British Columbia Native kindreds.

A locus (CPX) responsible for X-linked cleft palate and ankyloglossia was previously mapped to the proximal long arm of the X chromosome through DNA marker linkage studies in two large kindred: an Icelandic family and a British Columbia (B.C.) Native family. In this study, additional linkage analyses have been performed in the B.C. family and in a newly identified Manitoba Mennonite family with X-linked cleft palate and ankyloglossia. The Manitoba CPX locus maps to the same region as Icelandic and B.C. CPX. Two-point disease-to-marker linkage analyses in the Manitoba family indicate a maximum lod score (Zmax) between CPX and DXS349 (Zmax = 3.33 at theta = 0.0). In multipoint linkage analysis, combined data from the B.C. and Manitoba families suggest that the most likely location for CPX is at DXS447 in Xq21.1 (multipoint Z = 13.5). The support interval for CPX at DXS447 extends approximately from PGK1 to DXYS1 and includes a newly isolated polymorphic locus DXS1109.

Autoradiography↗

Inherited cancers associated with the RET proto-oncogene.

Mutations in the RET proto-oncogene have been identified in the constitutional DNA of patients with the inherited disorders multiple endocrine neoplasia type 2A and 2B and familial medullary thyroid carcinoma. This review focuses on the discoveries over the past year that pointed to RET as a candidate gene, and on the nature and spectrum of what appear to be dominant mutations associated with an inherited predisposition to tumor development.

Amino Acid Sequence↗

Regional localization of loci on chromosome 14 using somatic cell hybrids.

We have used a panel of human x rodent somatic cell hybrids containing translocations involving chromosome 14 to regionally localize 17 genes and 5 random segments previously mapped to chromosome 14. Each hybrid cell line contains a specific fragment of chromosome 14, with breakpoints at 14q11.2, 14q21, 14q22, 14q24.3 or in two different regions of 14q32.1. The enzyme deficient in glycogen storage disease type VI, liver glycogen phosphorylase (PYGL), has been localized by in situ hybridization to 14q21-->q22, near the q21-->q22 band interface. Four additional genes, chromogranin A (CHGA), myosin (MYH7), tRNA proline 2 (TRP2) and c-FOS (FOS) and four random segments, D14S26, D14S12, D14S14 and D14S13 have been more precisely localized. This study also defines a hybrid cell panel with seven mapping intervals, that will be useful for further physical mapping of new loci.

Animals↗

Parent-of-origin effects in multiple endocrine neoplasia type 2B.

Multiple endocrine neoplasia type 2B (MEN 2B) is characterized by medullary thyroid carcinoma, pheochromocytomas, mucosal neuromas, ganglioneuromas, and skeletal and ophthalmic abnormalities. It is observed as both inherited and sporadic disease, with an estimated 50% of cases arising de novo. A single point mutation in the catalytic core region of the receptor tyrosine kinase, RET, has been observed in germ-line DNA of MEN 2B patients. We have analyzed 25 cases of de novo disease in order to determine the parental origin of the mutated RET allele. In all cases the new mutation was of paternal origin. We observe a distortion of the sex ratio in both de novo MEN 2B patients and the affected offspring of MEN 2B transmitting males. These results suggests a differential susceptibility of RET to mutation in paternally and maternally derived DNA and a possible role for imprinting of RET during development.

Chromosomes, Human, Pair 10↗

Physical and genetic maps for chromosome 10.

A fluorescence in situ hybridization (FISH) physical map of 14 polymorphic loci on chromosome 10 covers over 62% of the fractional length of chromosome 10. The positions of three previously mapped loci are confirmed, nine more are refined, and two new loci are cytogenetically mapped. The order of loci determined by FISH agrees with that obtained by genetic linkage studies. When the distance estimates for the physical map are compared to the distance estimates of our existing linkage map, the sex average ratio of the fractional length (FL) per centimorgan (cM) for this portion of chromosome 10 is 0.004 (or 0.4% FL/cM). However, the average ratios for male- and female-specific genetic distances are quite different, in agreement with an overall higher rate of recombination in females (0.008 FL/cM and 0.003 FL/cM, respectively). Moreover, the ratio across the centromere is larger for both the male (0.031 FL/cM) and the female (0.009 FL/cM) than the ratio encompassing the q arm (0.006 FL/cM for males and 0.002 FL/cM for females), suggesting that there is reduced recombination at the centromere in both the male and the female maps when compared to the physical distance generated from FISH on metaphase chromosomes.

Chromosome Mapping↗

Genomic and yeast artificial chromosome long-range physical maps linking six loci in 10q11.2 and spanning the multiple endocrine neoplasia type 2A (MEN2A) region.

Multiple endocrine neoplasia types 2A and 2B (MEN 2A and MEN 2B) and familial medullary thyroid carcinoma (FMTC) are dominantly inherited cancers that have in common the clinical feature of medullary thyroid carcinoma (MTC). We have performed both genomic long-range restriction mapping and yeast artificial chromosome (YAC) contig assembly and restriction mapping to establish physical linkage, order, and distances between six loci in 10q11.2 near the genes responsible for these hereditary cancers. RET, D10S94, D10S182, and D10S102 have been mapped in genomic DNA. RET, D10S94, D10S182, D10F38S3, and the 10q11.2 sequences detected by DNA marker DM124 are encompassed by a 1-Mb YAC contig. Six physically linked loci are within 1.4 Mb and have an order and orientation of 10cen, D10F38S3, DM124, RET, D10S94, D10S182, D10S102, 10qter. Mutations in the RET proto-oncogene have recently been demonstrated to be associated with MEN 2A and FMTC. RET is located within a genetically defined MEN2A candidate interval between D10S141 and D10S94; MEN2B has been mapped to a larger, overlapping region between D10S141 and a more distal locus, RBP3. Both our genomic physical map and our YAC contig span the entire MEN2A candidate region and overlap with that of MEN2B. These maps will facilitate the identification of genes that can be considered candidates for MEN2B and the identification of tumor-specific alterations important in sporadic MTC.

Base Sequence↗

A new polymorphic marker (D10S97) tightly linked to the multiple endocrine neoplasia type 2A (MEN2A) locus.

Familial multiple endocrine neoplasia type 2A (MEN 2A) is a cancer syndrome that is inherited as an autosomal dominant with high penetrance. Its clinical features are medullary carcinoma of the thyroid, pheochromocytomas, and hyperparathyroidism. A new polymorphic locus D10S97 (probe: KW6 delta SacI) detects a codominant EcoRI polymorphism that is tightly linked to the MEN2A locus. The peak lod score for linkage between D10S97 with MEN2A is 13.03 at theta = 0.00. The polymorphic locus D10S97 maps, by linkage analysis, into the previously defined interval between FNRB and RBP3 to which MEN2A has been assigned. We present physical mapping data showing that the probe pKW6 originates from 10p13 and that the polymorphic locus D10S97 in 10q11.2 is detected by cross-hybridization.

Animals↗