Plexin B1 is downregulated in renal cell carcinomas and modulates cell growth.
Plexins are a family of transmembrane receptors that interact with the repulsive axon guidance molecules (Semaphorins) in neural tissues. In extraneural tissues, plexins are involved in other cellular functions often altered in neoplastic cells, such as adhesion, migration, and apoptosis. Plexin B1 has been implicated in the regulation of Akt, which is an activated pathway in renal cell neoplasms, and only 1 report has emphasized its role as an oncogenic factor. Furthermore, plexin B1 is located in 3p21, which is a chromosomal region deleted frequently in renal cell carcinomas. In accordance with a hypothetical oncogenic role for plexin B1, we have shown by reverse transcription-polymerase chain reaction that plexin B1 is expressed in nonneoplastic renal tissue, and it is severely downregulated in clear cell renal carcinomas. We have also demonstrated by immunohistochemistry on tissue microarrays that plexin B1 protein is absent in more than 80% of renal cell carcinomas (169 in 209 carcinomas examined). Otherwise, all kinds of renal tubules showed strong membrane reactivity. Moreover, when we have induced plexin B1 expression with an expression vector in the renal adenocarcinoma cell line ACHN, a marked reduction in proliferation rate was produced. Altogether, this evidence suggests a possible role for plexin B1 in renal oncogenesis.
Gómez Román
J Javier
JJ
Departamento de Anatomía Patológica, Hospital Universitario "Marqués de Valdecilla," Servicio Cántabro de Salud, Facultad de Medicina, Universidad de Cantabria, Santander, Spain. apagrj@humv.es
Garay
Gorka Ochoa
GO
Saenz
Pilar
P
Escuredo
Kepa
K
Sanz Ibayondo
Cristina
C
Gutkind
Silvio
S
Junquera
Corina
C
Simón
Laureano
L
Martínez
Antonio
A
Fernández Luna
José Luis
JL
Val-Bernal
J Fernando
JF
D017209:Apoptosis / Q000235:genetics; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D049109:Cell Proliferation; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D040081:Protein Array Analysis; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012016:Reference Values; D012189:Retrospective Studies; D039961:Semaphorins / Q000378:metabolism
D014408:Biomarkers, Tumor; D009419:Nerve Tissue Proteins; C492119:PLXNB1 protein, human; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D039961:Semaphorins; D051057:Proto-Oncogene Proteins c-akt