title: Cyclin B1, unlike cyclin G1, increases significantly during colorectal carcinogenesis and during later metastasis to lymph nodes.
abstract: In collaboration with p53, cyclins B1 and G1 regulate the G2/M transition, a key checkpoint in the active cell cycle, which can be monitored by Ki67. However, the cyclin B1 expression remains unclear during colorectal carcinogenesis and during later metastasis to lymph nodes, and cyclin G1 expression is not clear in colorectal tumors. To clarify the variations of the two cyclins in colorectal tumors, cyclin B1, cyclin G1, p53, and Ki67 were immunohistochemically stained in 22 normal mucosa, 62 adenomas, 17 carcinomas in adenomas, 194 primary carcinomas, and 21 lymph node metastases; and the two cyclins were examined by Western blot in other 10 pairs of normal mucosa and primary carcinomas. Located in cytoplasms, nuclei or both, cyclin B1 expression increased significantly from normal mucosa through adenomas to primary carcinomas, from adenomas with mild dysplasia through those with moderate to those with severe, from peripheral adenomas to their central carcinomas, and from primary to metastatic foci. These increased expressions were confirmed by Western blot. Cyclin B1 expression, however, declined significantly in primary carcinomas showing large size, mucinous type, deep invasion, or short postoperative-patient-survival time. High cyclin B1 was linked to high p53 in adenomas, and to high Ki67 in adenomas and primary carcinomas. In contrast, found limited to nuclei, cyclin G1 expression did not vary significantly from normal mucosa through to metastatic carcinomas, and was not associated with clinicopathological parameters, p53 or Ki67. The unchanged expressions were confirmed by Western blot. Thus, increased cyclin B1, but not cyclin G1, may promote colorectal carcinogenesis and later metastasis to lymph nodes.
authors.affiliation: Department of Pathology and Host-Defense, Kagawa Medical University, Kagawa 761-0793, Japan.
authors.forename: Jia-Qing
authors.initials: JQ
authors.lastname: Li
authors.forename: Akihito
authors.initials: A
authors.lastname: Kubo
authors.forename: Fei
authors.initials: F
authors.lastname: Wu
authors.forename: Hisashi
authors.initials: H
authors.lastname: Usuki
authors.forename: Jiro
authors.initials: J
authors.lastname: Fujita
authors.forename: Shuji
authors.initials: S
authors.lastname: Bandoh
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Masaki
authors.forename: Kousuke
authors.initials: K
authors.lastname: Saoo
authors.forename: Hijiri
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Shoji
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Imaida
authors.forename: Hajime
authors.initials: H
authors.lastname: Maeta
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ishida
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kuriyama
mesh_terms: D000236:Adenoma / Q000473:pathology; D000368:Aged; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D019926:Cyclin B / Q000378:metabolism*; D056744:Cyclin B1; D056746:Cyclin G; D056766:Cyclin G1; D016213:Cyclins / Q000378:metabolism*; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000473:pathology / Q000556:secondary; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D011379:Prognosis; D016019:Survival Analysis
chemical_list: C534699:CCNB1 protein, human; C534702:CCNG1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D056746:Cyclin G; D056766:Cyclin G1; D016213:Cyclins