pRb2/p130 protein in relation to clinicopathological and biological variables in rectal cancers with a clinical trial of preoperative radiotherapy.
BACKGROUND
pRb2/p130 plays a key role in cell proliferation and is a considerable progress about expression patterns of pRb2/p130 in number of malignancies. However, pRb2/p130 expression and its significance in rectal cancer remain unknown. The purpose of the present study was to investigate pRb2/p130 protein patterns and their correlations with clinicopathological and biological factors in rectal cancer patients with or without preoperative radiotherapy (RT).


METHODS
pRb2/p130 protein was examined by immunohistochemistry in 130 primary tumors, along with the corresponding 61 distant normal mucosa specimens, 85 adjacent normal mucosa specimens, 34 lymph node metastases, and 93 primary tumor biopsies from rectal cancer patients who participated in a Swedish clinical trial of preoperative RT.


RESULTS
The pRb2/p130 protein was mainly localized in the cytoplasm of tumor cells. In nonradiated cases, the lack of pRb2/p130 was related to advanced tumor-node-metastases stage, poorer differentiation, weak fibrosis, less inflammatory infiltration, higher Ki-67, and positive Cox-2 expression (p < 0.05). In radiated cases, the lack of pRb2/p130 was related to nonstaining of Cox-2 and survivin (p < 0.05). pRb2/p130 protein in primary tumors tended to be increased after RT (27% vs 16%, p = 0.07).


CONCLUSIONS
pRb2/p130 was mainly localized in the cytoplasm rather than in the nucleus in rectal cancer. After RT, pRb2/p130 protein seems to be increased in primary tumors, and further the relationship of the pRb2/p130 with the clinicopathological and biological variables changed compared to the nonradiated cases. However, we did not find that the pRb2/p130 was directly related to RT, tumor recurrence, and patients' survival.
Moparthi
Satish Babu
SB
Department of Oncology, Institute of Clinical and Experimental Medicine, Linköping University, 581 83 Linköping, Sweden.
Bergman
Viveka
V
Adell
Gunnar
G
Thorstensson
Sten
S
Sun
Xiao-Feng
XF
D000368:Aged; D001706:Biopsy; D015153:Blotting, Western; D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism / Q000473:pathology; D009362:Neoplasm Metastasis; D011300:Preoperative Care; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D050717:Retinoblastoma-Like Protein p130 / Q000378:metabolism*; D013194:Staining and Labeling
C493837:RBL2 protein, human; D050717:Retinoblastoma-Like Protein p130