Hypoxia and metabolic phenotypes during breast carcinogenesis: expression of HIF-1alpha, GLUT1, and CAIX.
Hypoxia and acidosis are microenvironmental selection forces during somatic evolution in breast carcinogenesis. The effect of cobalt chloride (CoCl(2))-induced hypoxia on the expression of hypoxia-inducible factor (HIF)-1alpha, glucose transporter 1 (GLUT1), and carbonic anhydrase IX (CAIX) was assessed in breast cancer cells derived from primary sites (HCC1395 and HCC1937) and metastatic sites (MCF-7 and MDA-MB-231) by reverse transcriptase-polymerase chain reaction and immunoblotting. We analyzed these proteins' expression in tissue samples from normal breast tissue, usual ductal hyperplasia (DH), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC) using immunohistochemistry. CAIX mRNA was expressed constitutively in MDA-MB-231 cells but not in the other three cell lines. CAIX mRNA expression was increased after CoCl(2)-induced hypoxia in all four breast cancer cell lines. The expression of HIF-1alpha and GLUT1 proteins was increased after CoCl(2)-induced hypoxia in all breast cancer cell lines tested. Hypoxia significantly increased CAIX protein expression in primary cancer cells but not in metastatic ones. HIF-1alpha was not expressed in benign breast tissue, whereas it was significantly expressed in DH, ADH, DCIS, and IDC (p < 0.001). GLUT1 and CAIX were expressed only in DCIS (56.8% and 25.0%) and IDC (44.1% and 30.5%), with higher expression in high grade DCIS than low/intermediate grade DCIS (79.2% vs. 30.0%, p = 0.001 and 37.5% vs. 10.0%, p = 0.036, respectively). High CAIX expression was significantly associated with poor histological grade of IDC (p = 0.005). During breast carcinogenesis, the role of HIF-1alpha changes from response to proliferation to tumor progression. GLUT1 expression (glycolytic phenotype) and CAIX expression (acid-resistant phenotype) may result in a powerful adaptive advantage and represent an aggressive phenotype.
Department of Pathology, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Chi-Long
CL
Chen
Jan-Show
JS
Chu
Wu-Chou
WC
Su
Soon-Cen
SC
Huang
Wen-Ying
WY
Lee
D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000235:genetics; D016587:Antimutagenic Agents / Q000633:toxicity; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000096:biosynthesis* / Q000235:genetics; D002278:Carcinoma in Situ / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015687:Cell Hypoxia / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D003035:Cobalt / Q000633:toxicity; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D051272:Glucose Transporter Type 1 / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D006965:Hyperplasia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis* / Q000235:genetics; D007150:Immunohistochemistry; D010641:Phenotype; D011230:Precancerous Conditions / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000951:Antigens, Neoplasm; D016587:Antimutagenic Agents; D051272:Glucose Transporter Type 1; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; C495677:SLC2A1 protein, human; D003035:Cobalt; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases; C018021:cobaltous chloride