title: Immunohistochemical analysis of thymidylate synthase, p16(INK4a), cyclin-dependent kinase 4 and cyclin D1 in colorectal cancers receiving preoperative chemotherapy: significance of p16(INK4a)-mediated cellular arrest as an indicator of chemosensitivity to 5-fluorouracil.
abstract: High expression of thymidylate synthase (TS) is allegedly associated with the chemoresistance to 5-fluorouracil (5-FU) in colorectal cancers. However, low TS expression does not necessarily imply chemosensitivity. Inactivation of p16(INK4a) correlates with poor prognosis in various cancers. We immunohistochemically evaluated the relationship between the expression of TS, p16(INK4a), CDK4 and cyclin D1 and the effect of 5-FU-based chemotherapy in colorectal cancers. After antigen retrieval, immunoperoxidase staining was performed on the paraffin-embedded, biopsy and surgical specimens of 37 advanced colorectal cancers preoperatively treated with peroral administration of 5-FU derivatives. As a control group, 31 colorectal cancers without preoperative treatment were analyzed. High TS expression was found in 23 (74%) of 31 tumors resected from histological non-responders and in 19 (61%) of 31 controls but in none of six responders. High p16(INK4a) expression was seen in 83% of the responders, 52% of the non-responders and 32% of the controls. The TS-low/p16(INK4a)-high phenotype was noted in 83% of the responders, but only in 3% of the non-responders (P = 0.0001). Induction of p16(INK4a) expression after chemotherapy was predominantly seen in the responders. Neither CDK4 nor cyclin D1 expression was related to the chemotherapeutic effects. In conclusion, the combination of low expression of TS and induction of p16(INK4a) after chemotherapy can be important indicators of the sensitivity to 5-FU-based chemotherapy in colorectal cancers.
authors.affiliation: Department of Pathology, Fujita Health University School of Medicine, Toyoake, Japan. skamo@fujita-hu.ac.jp
authors.forename: Shingo
authors.initials: S
authors.lastname: Kamoshida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuoka
authors.forename: Kazuya
authors.initials: K
authors.lastname: Shiogama
authors.forename: Atsuji
authors.initials: A
authors.lastname: Matsuyama
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Shimomura
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Inada
authors.forename: Morito
authors.initials: M
authors.lastname: Maruta
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tsutsumi
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism* / Q000556:secondary; D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D019938:Cyclin D1 / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D013940:Thymidylate Synthase / Q000378:metabolism*; D016896:Treatment Outcome
chemical_list: D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16; D011518:Proto-Oncogene Proteins; D019938:Cyclin D1; D013940:Thymidylate Synthase; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases; D005472:Fluorouracil