title: Amplification, up-regulation and over-expression of C3G (CRK SH3 domain-binding guanine nucleotide-releasing factor) in non-small cell lung cancers.
abstract: The Ras-CRK-Rap1 cellular signal-transduction system is regulated by guanine nucleotide exchange factors (GEFs). Transcription of C3G on chromosome 9q34 and a key member of the GEF gene family is activated by the CRK-adaptor protein; the C3G product is a CRK SH3 domain-binding guanine nucleotide-releasing factor. We document here the amplification of C3G in five of 18 primary non-small cell lung cancers examined and its increased expression in 18 of 28 tumors in comparison to corresponding non-cancerous lung tissues. Immunohistochemical staining revealed prominent C3G protein in the cytoplasm of cancer cells, associated with faint staining at the nucleolar membrane, but C3G was not detectable in normal bronchial mucoepithelial cells or in broncholoalveolar cells of the bronchial/bronchiolar ducts or alveoli. These data indicate that amplification and increased expression of the C3G gene may play some role in human lung carcinogenesis through derangement of the CRK-Rap1 signaling pathway.
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Hirata
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan.
authors.forename: Hisaki
authors.initials: H
authors.lastname: Nagai
authors.affiliation: Department of Biological Regulation and Regenerative Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Koizumi
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Okino
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan.
authors.forename: Akima
authors.initials: A
authors.lastname: Harada
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan.
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Onda
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan.
authors.forename: Takemitsu
authors.initials: T
authors.lastname: Nagahata
authors.affiliation: Department of Biological Regulation and Regenerative Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
authors.forename: Iwao
authors.initials: I
authors.lastname: Mikami
authors.affiliation: Department of Biological Regulation and Regenerative Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
authors.forename: Kyoji
authors.initials: K
authors.lastname: Hirai
authors.affiliation: Department of Biological Regulation and Regenerative Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
authors.forename: Syuji
authors.initials: S
authors.lastname: Haraguchi
authors.affiliation: Department of Pathology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-8533, Japan.
authors.forename: Enjing
authors.initials: E
authors.lastname: Jin
authors.affiliation: Department of Pathology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-8533, Japan.
authors.forename: Oichi
authors.initials: O
authors.lastname: Kawanami
authors.affiliation: Department of Biological Regulation and Regenerative Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan. memi@nms.ac.jp.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Emi
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002466:Cell Nucleolus; D002899:Chromosomes, Human, Pair 9; D003593:Cytoplasm / Q000378:metabolism; D004247:DNA / Q000737:chemistry; D005260:Female; D018628:Gene Dosage; D015972:Gene Expression Regulation, Neoplastic; D020735:Guanine Nucleotide-Releasing Factor 2 / Q000096:biosynthesis* / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism*; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D050737:Proto-Oncogene Proteins c-crk; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014158:Transcription, Genetic; D015854:Up-Regulation; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; C485285:CRK protein, human; D020735:Guanine Nucleotide-Releasing Factor 2; D050737:Proto-Oncogene Proteins c-crk; D012333:RNA, Messenger; D004247:DNA; D020827:rap1 GTP-Binding Proteins