Connexin expression by human granulosa cell tumors: Identification of connexin 32 as a tumor signature.
Human granulosa cell (GC)-tumors are assumed to arise from ovarian GCs but to what extent they resemble normal human GCs is not well established. We examined whether a prominent feature of normal GCs, expression of the major gap junctional protein connexin 43 (Cx43), was retained in 14 human GC-tumor samples. Immunohistochemistry revealed areas of strong staining side by side with areas of weak and/or no staining. If present, cytoplasmic and membrane-associated Cx43 staining occurred. In cells with reduced or absent Cx43, another Cx was found, Cx32. Cx32, which is absent from non-tumor GCs, was present in GC-tumor cells co-expressed in part with Cx43 at gap junctional plaques. Expression of Cx32 and Cx43 was confirmed by RT-PCR and sequencing in the majority of tumor samples. Thus GC-tumor cells are characterized by a partial or complete loss of Cx43 expression and expression of Cx32, which may be a marker for these rare tumors. It is possible that the pattern of Cxs may contribute to tumor formation and growth, as it may indicate aberrant and/or reduced cell-to-cell communication ability.
Anatomy and Cell Biology, Ludwig-Maximilian-University of Munich, Munich, Germany Department of Pathology, Ludwig-Maximilian-University of Munich, Munich, Germany.
Catherina
C
Lücke
Silvana
S
Siebert
Doris
D
Mayr
Artur
A
Mayerhofer
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D002450:Cell Communication; D002648:Child; D018031:Connexin 43 / Q000096:biosynthesis* / Q000378:metabolism; D017630:Connexins / Q000096:biosynthesis* / Q000378:metabolism; D005260:Female; D017629:Gap Junctions / Q000378:metabolism; D006106:Granulosa Cell Tumor / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D000097002:Gap Junction beta-1 Protein
D014408:Biomarkers, Tumor; D018031:Connexin 43; D017630:Connexins; D012333:RNA, Messenger; D000097002:Gap Junction beta-1 Protein