Homeodomain-interacting protein kinase 1 (HIPK1) expression in breast cancer tissues.
OBJECTIVE
This study investigated the incidence and clinical significance of homeodomain-interacting protein kinase 1 expression in breast cancer patients.


METHODS
We investigated immunohistochemical homeodomain-interacting protein kinase 1 expression from tissue microarrays of 1032 patients. The association of homeodomain-interacting protein kinase 1 expression pattern, clinicopathologic factors and survival outcome was evaluated. Tumors with ≥10% stained cells were considered positive for homeodomain-interacting protein kinase 1.


RESULTS
Non-cancerous breast tissue, pTis and pT1mic lesions did not show homeodomain-interacting protein kinase 1 expression at any sites. Of the 859 invasive tumors, 124 (14.4%) showed homeodomain-interacting protein kinase 1 expression with three different expression patterns: cytoplasmic (2.4%), nuclear (6.3%), and both cytoplasmic and nuclear (5.7%). Cytoplasmic homeodomain-interacting protein kinase 1-positive tumors showed distinctive features such as fewer nodal metastases, but were frequently Grade III, estrogen receptor-negative, progesterone receptor-negative, HER2-positive, highly proliferative and molecular apocrine tumors. No significant difference in clinicopathologic features was identified between negative and nuclear homeodomain-interacting protein kinase 1-positive tumors. Both cytoplasmic and nuclear HIPK1-positive tumors represent frequent small size, node negativity and moderately differentiated features. Survival was not significantly different by homeodomain-interacting protein kinase 1 expression patterns.


CONCLUSIONS
Homeodomain-interacting protein kinase  1 expression was identified only in invasive breast cancer cells with three different patterns: cytoplasmic, nuclear, and both cytoplasmic and nuclear. Although the mechanism is not certain, the subcellular localization of HIPK1 expression is associated with tumor histopathologic characteristics and different functions.
Department of Surgery and Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea. bwpark@yuhs.ac
Byeong-Woo
BW
Park
Seho
S
Park
Ja Seung
JS
Koo
Seung Il
SI
Kim
Ji Min
JM
Park
Jung Hoon
JH
Cho
Hyung Seok
HS
Park
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D056910:Republic of Korea / Q000453:epidemiology; D015996:Survival Rate; D046888:Tissue Array Analysis
D014408:Biomarkers, Tumor; C543644:HIPK1 protein, human; D017346:Protein Serine-Threonine Kinases