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24-448: MASC may refer to: Mammary analogue secretory carcinoma Manually Annotated Sub-Corpus MASC (band) , a South Korean boy band Master of Applied Science (MASc), an academic degree MASC, a song by Doja Cat and Teezo Touchdown from the album Scarlet (Doja Cat album) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with

48-533: A species constitutes the genome , the entire set of exons constitutes the exome . The term exon derives from the expressed region and was coined by American biochemist Walter Gilbert in 1978: "The notion of the cistron ... must be replaced by that of a transcription unit containing regions which will be lost from the mature messenger – which I suggest we call introns (for intragenic regions) – alternating with regions which will be expressed – exons." This definition

72-550: A large fraction of non-coding DNA . For instance, in the human genome only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA . This can provide a practical advantage in omics -aided health care (such as precision medicine ) because it makes commercialized whole exome sequencing a smaller and less expensive challenge than commercialized whole genome sequencing . The large variation in genome size and C-value across life forms has posed an interesting challenge called

96-482: A standard technique in developmental biology . Morpholino oligos can also be targeted to prevent molecules that regulate splicing (e.g. splice enhancers, splice suppressors) from binding to pre-mRNA, altering patterns of splicing. Common incorrect uses of the term exon are that 'exons code for protein', or 'exons code for amino-acids' or 'exons are translated'. However, these sorts of definitions only cover protein-coding genes , and omit those exons that become part of

120-444: A tyrosine kinase to phosphorylate cellular proteins and thereby stimulate cell signaling pathways that lead to cellular differentiation and growth while inhibiting cellular death . TrkC makes particularly important contributions to development of the central and peripheral nervous systems . NTRK3 forms chromosomal translation-mediated fusions with many other genes in addition to ETV6 to form fused genes that are associated with

144-520: Is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing . The term exon refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts. In RNA splicing, introns are removed and exons are covalently joined to one another as part of generating the mature RNA . Just as the entire set of genes for

168-544: Is responsible for its dimerization/polymerization ETV6 , a step required for it to inhibit transcription. The protein's C-terminus contains the C-terminus of the TrkC. The fusion protein lacks transcription regulating activity but has dysregulated, i.e. continuously active tyrosine kinase activity. In consequence of the latter effect, the fusing protein continuously stimulates pro-growth and pro-survival pathways and thereby

192-716: The ETV6 gene located on the short arm (designated p) of chromosome 12 at position p13.2 (i.e. 12p13.2) and the NTRK3 gene located on the long arm (designated q) of chromosome 15 at position q25.3 (i.e. 15q25.3) to create the (12;15)(p13;q25) fusion gene , ETV6-NTRK3 . This mutant fusion gene also occurs in congenital fibrosarcoma , congenital mesoblastic nephroma , secretory breast cancer (also termed juvenile breast cancer), acute myelogenous leukemia , ALK-negative Inflammatory myofibroblastic tumour , and radiation-induced papillary thyroid carcinoma . The MASC SG gene codes for

216-657: The C-value enigma . Across all eukaryotic genes in GenBank, there were (in 2002), on average, 5.48 exons per protein coding gene. The average exon encoded 30-36 amino acids . While the longest exon in the human genome is 11555 bp long, several exons have been found to be only 2 bp long. A single-nucleotide exon has been reported from the Arabidopsis genome. In humans, like protein coding mRNA , most non-coding RNA also contain multiple exons In protein-coding genes,

240-670: The ETV6-NTRK3 fusion gene using Fluorescence in situ hybridization or reverse transcription polymerase chain reaction gene detection methods or b) a specific pattern of marker proteins as registered using specific antibody-based detection methods, i.e. MASC SG tissue should have detectable S100 (a family of calcium binding proteins), Mammaglobin (a breast cancer marker ), Keratin 7 (an intermediate filament found in epithelial cells), GATA3 (a transcription factor and breast cancer biomarker), SOX10 (a transcription factor important in neural crest origin cells and development of

264-462: The transcription factor protein, ETV6, which suppresses the expression of, and thereby regulates, various genes that in mice are required for normal hematopoiesis as well as the development and maintenance of the vascular network. The NTRK3 gene codes for Tropomyosin receptor kinase C (also termed TrkC or TEL), the receptor for neurotrophin-3 . TrkC is a RTK class VII tyrosine kinase receptor . When bound to neurotrophin-3, it becomes active as

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288-587: The exon that is contained in the insertional DNA . This new exon contains the ORF for a reporter gene that can now be expressed using the enhancers that control the target gene. A scientist knows that a new gene has been trapped when the reporter gene is expressed. Splicing can be experimentally modified so that targeted exons are excluded from mature mRNA transcripts by blocking the access of splice-directing small nuclear ribonucleoprotein particles (snRNPs) to pre-mRNA using Morpholino antisense oligos . This has become

312-460: The exons include both the protein-coding sequence and the 5′- and 3′- untranslated regions (UTR). Often the first exon includes both the 5′-UTR and the first part of the coding sequence, but exons containing only regions of 5′-UTR or (more rarely) 3′-UTR occur in some genes, i.e. the UTRs may contain introns. Some non-coding RNA transcripts also have exons and introns. Mature mRNAs originating from

336-464: The induction of a wide range of cancers including those of the lung, thyroid gland, colon, rectum, and brain. ETV6-NTRK3 fusion genes in some MASC SG disease cases display atypical exon junctions and may be associated with more tissue infiltrating disease and less favorable clinical outcomes. The ETV6-NTRK3 fusion gene's product, ETV6-NTRK3 protein, contains the N-terminus of ETV6 that

360-646: The location of disease. Mean disease-free survival for MASC SG patients has been reported to be 92 months in one study. The tyrosine kinase activity of NTRK3 as well as the ETV6-NTRK3 protein is inhibited by certain tyrosine kinase inhibitory drugs such as Entrectinib and LOXO-101 ; this offers a potential medical intervention method using these drugs to treat aggressive MASC SG disease. Indeed, one patient with extensive head and neck MASC SG disease obtained an 89% fall in tumor size when treated with entrectinib. This suppression lasted only 7 months due to

384-438: The malignant growth of its parent cells. Mammary analogue secretory carcinoma occurs somewhat more commonly in men (male to female ratio of <1.5:1.0). Patients with this disease have a mean age of 46 years although ~12% of cases occur in pediatric patients. Individuals typically present with symptomless tumors in the parotid salivary gland (68%), buccal mucosa salivary glands (9%), submandibular salivary gland (8%) or in

408-413: The peripheral nervous system), and STAT5A (a transcription factor) but lack antibody-detectable TP63 (a transcription factor in the same family as p53) and Anoctamin-1 (a voltage sensitive calcium activated chloride channel). MASC SG is currently treated as a low-grade (i.e. Grade 1) carcinoma with an overall favorable prognosis. These cases are treated by complete surgical excision. However,

432-573: The presence of vesicular oval nuclei with a single small but prominent nucleolus ; and the absence of basophilic Haematoxylin or zymogen granules (i.e. vesicles that store enzymes near the cell's plasma membrane). The cited histology features are insufficient to distinguish MASC SG from other Salivary gland neoplasms such as acinic cell carcinoma , low-grade cribriform cystadenocarcinoma, and adenocarcinoma not otherwise specified. MASC SG can be distinguished from these and other histologically similar tumors by either tissue identification of a)

456-428: The same gene need not include the same exons, since different introns in the pre-mRNA can be removed by the process of alternative splicing . Exonization is the creation of a new exon, as a result of mutations in introns . Exon trapping or ' gene trapping ' is a molecular biology technique that exploits the existence of the intron-exon splicing to find new genes. The first exon of a 'trapped' gene splices into

480-554: The small salivary glands of the lower lip (5%), upper lip (4%), and hard palate (4%). Histologically , these tumors are described as having a morphology similar to secretory breast carcinoma; they typically having one or more of the following histological patterns: microcystic, papillary-cystic, follicular, and/or solid lobular. Other histological features of these tissues include: the presence of eosinophilic secretions as detected by staining strongly for eosin Y ; positive staining with periodic acid-Schiff stain (often after diastase );

504-573: The title MASC . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=MASC&oldid=1249924060 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Mammary analogue secretory carcinoma The translocation found in MASC SG occurs between

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528-695: The tumor does have the potential to recur locally and/or spread beyond surgically dissectible margins as well as metastasize to regional lymph nodes and distant tissues, particularly in tumors with histological features indicating a high cell growth rate potential. One study found lymph node metastasis in 5 of 34 MASC SG patients at initial surgery for the disease; these cases, when evidencing no further spread of disease, may be treated with radiation therapy . The treatment of cases with disease spreading beyond regional lymph nodes has been variable, ranging from simple excision to radical resections accompanied by adjuvant radiotherapy and/or chemotherapy , depending on

552-422: The tumor's acquirement of a mutation in the ETV6-NTRK3 gene. The newly mutated gene encoded an entrectinib-reisistant ETV6-NTRK3 protein. Treatment of aggressive forms of MASC SG with NTRK3-inhibiting tyrosine kinase inhibiting drugs, perhaps with switching to another type of tyrosine kinase inhibitor drug if the tumor acquires resistance to the initial drug, is under study. STARTRK-2 Exon An exon

576-462: Was originally made for protein-coding transcripts that are spliced before being translated. The term later came to include sequences removed from rRNA and tRNA , and other ncRNA and it also was used later for RNA molecules originating from different parts of the genome that are then ligated by trans-splicing. Although unicellular eukaryotes such as yeast have either no introns or very few, metazoans and especially vertebrate genomes have

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