Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RET germline mutations were found to predispose to the development of three variants of multiple endocrine neoplasia type 2, MEN2A, MEN2B, and familial medullary thyroid carcinoma (FMTC). We have screened for RET mutations at exons 10, 11, 13, and 16 in leukocyte DNA extracted from 37 individuals, and have identified RET germline mutations in 12 affected individuals from 9 unrelated families. No RET germline mutation was found in 19 individuals with apparent sporadic diseases. We have also screened for RET mutations at exons 10, 11, and 16 in tumor DNA extracted from 13 freshly frozen medullary thyroid carcinomas (MTC). RET mutation was detected in every tumor, either inherited or sporadic, indicating that RET plays an important role in the development of both inherited and sporadic MTC. We initially screened for RET mutations by direct DNA sequencing of the genomic PCR products amplified from patients' leukocyte or tumor DNA. Recently, we utilized the "Cold SSCP" method, nonradioactive single-stranded conformation polymorphism analysis, to screen for RET mutations and have identified a novel mutation, a 6-bp deletion preceding the cysteine-634, in a sporadic MTC.
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PMID:RET mutation screening in MEN2 patients and discovery of a novel mutation in a sporadic medullary thyroid carcinoma. 873 82

Intrachromosomal rearrangements involving the RET and the adjacent H4 or ELE1 gene are very frequent events in thyroid cancer of children from Belarus after the Chernobyl reactor accident (Klugbauer et al., 1995). The fusion product between ELE1 and RET (RET/ PTC3) seems to be the prevailing type of rearrangement as shown in a recently published study using a novel RT multiplex PCR approach in combination with the identification of the rearrangement type by RT-PCR and direct sequencing. Now we found a new type of RET rearrangement: By the 5'RACE method we demonstrated in cDNA the fusion of the tyrosine kinase domain of RET with a truncated ELE1 gene shorter than the ELE1 in RET/PTC3. Sequencing of genomic DNA revealed a rearrangement breakpoint at position 41 of a new ELE1 intron (522 bp in length). The new oncogene RET/ delta PTC3 is shortened by one ELE1 exon of 144 bp in length. Structural considerations of the ele1 amino terminal of RET/ delta PTC3 suggest that the transforming activity of the fusion protein is apparently not affected by this truncation. The exon lacking in RET/ delta PTC3 was found to code in the reciprocal transcript RET/ delta ELE1 and increased its size by 144 bp. Obviously the new and possibly additional ELE/RET fusion molecules might even increase the high prevalence of ELE1/RET rearrangements in thyroid carcinomas of children after the Chernobyl reactor accident.
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PMID:A new form of RET rearrangement in thyroid carcinomas of children after the Chernobyl reactor accident. 880

The RET proto-oncogene is at the origin of one of the most interesting models of human disease caused by mutations in a receptor tyrosine kinase gene. Somatic rearrangements of RET are involved in the aetiology of a variable proportion of papillary thyroid carcinomas (PTC), the most common type of thyroid tumour whose prevalence is increasing in areas heavily exposed to radioactive fallout after the Chernobyl accident of 1986. Moreover, germline RET mutations are associated with the three variants of the inherited cancer syndrome known as multiple endocrine neoplasia type 2 (MEN2A, MEN2B and FMTC). Finally, RET mutations or heterozygous deletions of the whole gene cause the autosomal dominant form of Hirschsprung disease (HSCR), a congenital disorder of the enteric nervous system (ENS).
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PMID:RET mutations in human disease. 890 18

The NTRK1 gene encodes one of the receptors for the Nerve Growth Factors and it is located at 1q21-22. Rearrangements of NTRK1 are frequently detected in human papillary thyroid carcinoma and lead to the formation of chimeric oncogenes, similarly to what observed for the other neurotrophin receptor RET. In addition, the two receptor genes are target of point mutations associated with different human diseases. RET is affected by germ line and somatic mutations in MEN2A, MEN2B tumor syndromes and in the abnormal developmental Hirschsprung disease, whereas mutations of NTRK1 have been reported very recently in patients with congenital insensitivity to pain with anidrosis (CIPA). With the aim to provide a tool for searching mutations along the whole NTRK1 gene, we have determined its genomic organization. Our results demonstrated that NTRK1 is contained within 25 Kb of DNA and is organized in 17 exons, one of which is alternatively spliced. The sequence of the 5' flanking region indicates a high content in C/G, the absence of TATA box, the presence of several putative binding sites for Sp1, AP1, AP2, AP3, ATF and GCF transcription factors.
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PMID:Genomic organization of the human NTRK1 gene. 895 89

Missense germline mutations of the RET proto-oncogene have recently been identified in the hereditary cancer syndromes MEN2A, MEN2B, and FMTC, all characterized by medullary carcinoma, but also including phaeochromocytoma in MEN2A and MEN2B and parathyroid disease in MEN2A. In addition, somatic RET proto-oncogene mutations have been identified in a subset of sporadic medullary carcinomas and phaeochromocytomas. This study investigated the possibility that RET plays a role in sporadic parathyroid neoplasia. Firstly, normal and neoplastic parathyroid tissues were screened for expression of the RET proto-oncogene, using an RT-PCR approach on autopsy material. Secondly, 20 archival parathyroid adenomas were screened for somatic mutations in the transmembrane region of RET, the region associated with germline mutations in MEN2A and hence parathyroid disease, using a PCR-solid phase direct sequencing approach. RET expression was identified in all the parathyroid tissues analysed. However, no mutations were identified in any of the 20 adenomas, suggesting either that other mechanisms of RET activation occur, such as translocation, or that RET plays a more minor role in the growth control of the parathyroid cells than in C cells or phaeochromocytes.
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PMID:Analysis of the RET proto-oncogene in sporadic parathyroid adenomas. 897 70

Distinct point mutations of RET, a tyrosine-kinase receptor encoding gene, are responsible for the inheritance of multiple endocrine neoplasia type 2 syndromes (MEN2A and MEN2B) and familial medullary thyroid carcinoma (FMTC). In particular, MEN2A is a more complex and aggressive disease than FMTC, being characterized by pheochromocytomas and parathyroid alterations, in addition to medullary thyroid carcinomas. The mutations associated with MEN2A and FMTC affect one of five cysteine residues mapping in the extracellular domain of the Ret protein. However, recent studies have indicated that MEN2A and FMTC disease phenotypes correlate with the position of mutations in RET. Mutations of Cys-634 are more frequent in families with MEN2A, whereas Cys-620 mutations are very rarely found in MEN2A patients and, in contrast, are frequently found in FMTC patients. We have reported previously that mutations of Cys-634 constitutively activate the RET transforming potential by causing a disulfide bridge-mediated homodimerization. Here, we report that the mutation Cys-620 --> Tyr is able to cause a constitutive dimerization of Ret, with consequent activation of its kinase and transforming activities, to a lower extent than mutation of Cys-634. We suggest that the difference in ability to activate RET shown by mutations associated with FMTC and MEN2A represents the molecular basis of the phenotypic diversity between the two syndromes.
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PMID:The different RET-activating capability of mutations of cysteine 620 or cysteine 634 correlates with the multiple endocrine neoplasia type 2 disease phenotype. 901 62

The RET proto-oncogene encodes two isoforms of a receptor type tyrosine kinase which plays a role in neural crest and kidney development. Distinct germ-line mutations of RET have been associated with the inherited cancer syndromes MEN2A, MEN2B and FMTC as well as with the congenital disorder Hirschsprung disease (HSCR), whereas somatic rearrangements (RET/PTCs) have been frequently detected in the papillary thyroid carcinoma. Despite these findings, suggesting a relevant role for RET product in development and neoplastic processes, little is known about the signalling triggered by this receptor. In this study, we have demonstrated that the transducing adaptor molecule Shc is recruited and activated by both Ret isoforms and by the rearranged cytoplasmatic Ret/ptc2 oncoproteins as well as by the membrane bound receptor activated by MEN2A or by MEN2B associated mutations. Moreover, our analysis has identified the Ret tyrosine residue and the Shc domains involved in the interaction. In fact, here we show that both the phosphotyrosine binding domains of Shc, PTB and SH2, interact with Ret/ptc2 in vitro. However, PTB domain binds 20 folds higher amount of Ret/ptc2 than SH2. The putative binding site for either SH2 and PTB domains has been identified as Tyr586 of Ret/ptc2 (Tyr1062 on proto-Ret). In keeping with this finding, by using RET/PTC2-Y586F mutant, we have demonstrated that this tyrosine residue, the last amino acid but one before the divergence of the two Ret isoforms, is the docking site for Shc.
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PMID:Identification of Shc docking site on Ret tyrosine kinase. 904 84

Specific point-mutations of the RET receptor tyrosine kinase protooncogene are responsible for the inheritance of multiple endocrine neoplasia type 2A (MEN2A) and 2B (MEN2B), and familial medullary thyroid carcinoma (FMTC). MEN2B is caused by the substitution of methionine 918 by a threonine in the tyrosine kinase (TK) domain of RET. This mutation converts RET into a dominant transforming oncogene. We have substituted Met918 with four different residues and found that RET acquired transforming activity only when Met918 was substituted with a threonine. However, also when serine and valine, but not leucine or phenylalanine, were inserted in position 918, the RET TK function was activated and induced, especially in the case of the RET(918Ser), immmediate-early response genes. We conclude that the preservation of Met918 is critical for the control of RET kinase. However, only when a threonine residue is present in position 918, does RET efficiently couple with a transforming pathway.
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PMID:Only the substitution of methionine 918 with a threonine and not with other residues activates RET transforming potential. 907 1

Multiple endocrine neoplasia type 2 (MEN 2) is a dominantly inherited cancer syndrome that comprises three clinical subtypes: MEN type 2A (MEN-2A), MEN type 2B (MEN-2B), and familial medullary thyroid carcinoma (FMTC). Medullary thyroid carcinoma (MTC), a malignant tumor arising from calcitonin-secreting thyroid C cells, is the cardinal disease feature of this syndrome, and mortality in affected MEN-2 patients is mainly caused by this malignancy. Germ-line mutations of the RET protooncogene, which encodes a receptor tyrosine kinase, are responsible for these three neoplastic-prone disorders. MEN2 mutations convert the RET protooncogene in a dominantly acting oncogene as a consequence of the ligand-independent activation of the tyrosine kinase. The majority of MEN2A and FMTC mutations are located in the extracellular domain and cause the replacement of one of five juxtamembrane cysteines by a different amino acid. To examine whether expression of a MEN2A allele of RET results in transformation of C cells, we have used the transgenic approach. Expression of the RET gene altered by a MEN2A mutation was targeted in C cells by placing the transgene under the control of the calcitonin gene-related peptide/calcitonin promoter. Animals of three independent transgenic mouse lines, which expressed the transgene in the thyroid, displayed overt bilateral C cell hyperplasia as early as 3 weeks of age and subsequently developed multifocal and bilateral MTC. Moreover, these tumors were morphologically and biologically similar to human MTC which afflicts MEN2 individuals. These findings provide evidence that the MEN2A mutant form of RET is oncogenic in parafollicular C cells and suggest that these transgenic mice should prove a valuable animal model for hereditary MTC.
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PMID:Development of medullary thyroid carcinoma in transgenic mice expressing the RET protooncogene altered by a multiple endocrine neoplasia type 2A mutation. 909 93

Mutations in the RET proto-oncogene have recently been recognized to be responsible for the inherited multiple endocrine neoplasia type 2 syndrome. As expected, Greek patients with MEN2 and FMTC carry RET mutations similar to those of other ethnic groups. In those regions of the gene that were analyzed, mutations were detected in six out of six families with classical MEN2A, three out of five of the families with familial MTC, and one case with MEN2B. Presymptomatic screening using DNA analysis has now replaced calcitonin stimulation tests in the offspring of families where the mutation has been characterized. The use of these methods will improve the prognosis in MEN2 patients and will also reduce the psychological burden of risk for a potentially lethal disease on family members.
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PMID:Genetic screening for RET mutations in families with multiple endocrine neoplasia 2 syndromes. 923 92


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