title: Tumor suppressor activity and epigenetic inactivation of hepatocyte growth factor activator inhibitor type 2/SPINT2 in papillary and clear cell renal cell carcinoma.
abstract: Following treatment with a demethylating agent, 5 of 11 renal cell carcinoma (RCC) cell lines showed increased expression of hepatocyte growth factor (HGF) activator inhibitor type 2 (HAI-2/SPINT2/Bikunin), a Kunitz-type protease inhibitor that regulates HGF activity. As activating mutations in the MET proto-oncogene (the HGF receptor) cause familial RCC, we investigated whether HAI-2/SPINT2 might act as a RCC tumor suppressor gene. We found that transcriptional silencing of HAI-2 in RCC cell lines was associated with promoter region methylation and HAI-2/SPINT2 protein expression was down-regulated in 30% of sporadic RCC. Furthermore, methylation-specific PCR analysis revealed promoter region methylation in 30% (19 of 64) of clear cell RCC and 40% (15 of 38) of papillary RCC, whereas mutation analysis (in 39 RCC cell lines and primary tumors) revealed a missense substitution (P111S) in one RCC cell line. Restoration of HAI-2/SPINT2 expression in a RCC cell line reduced in vitro colony formation, but the P111S mutant had no significant effect. Increased cell motility associated with HAI-2/SPINT2 inactivation was abrogated by treatment with extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) and phospholipase C-gamma inhibitors, but not by an inhibitor of atypical protein kinase C. These findings are consistent with frequent epigenetic inactivation of HAI-2/SPINT2, causing loss of RCC tumor suppressor activity and implicate abnormalities of the MET pathway in clear cell and papillary sporadic RCC. This information provides opportunities to develop novel targeted approaches to the treatment of RCC.
authors.affiliation: Cancer Research UK Renal Molecular Oncology Group, University of Birmingham, Edgbaston, United Kingdom.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Morris
authors.forename: Dean
authors.initials: D
authors.lastname: Gentle
authors.forename: Mahera
authors.initials: M
authors.lastname: Abdulrahman
authors.forename: Esther N
authors.initials: EN
authors.lastname: Maina
authors.forename: Kunal
authors.initials: K
authors.lastname: Gupta
authors.forename: Rosamonde E
authors.initials: RE
authors.lastname: Banks
authors.forename: Michael S
authors.initials: MS
authors.lastname: Wiesener
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kishida
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yao
authors.forename: Bin
authors.initials: B
authors.lastname: Teh
authors.forename: Farida
authors.initials: F
authors.lastname: Latif
authors.forename: Eamonn R
authors.initials: ER
authors.lastname: Maher
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002291:Carcinoma, Papillary / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002448:Cell Adhesion / Q000502:physiology; D048708:Cell Growth Processes / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D002522:Chlorocebus aethiops; D019175:DNA Methylation; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D016147:Genes, Tumor Suppressor; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D014411:Neoplastic Stem Cells; D011401:Promoter Regions, Genetic; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019859:Proto-Oncogene Proteins c-met; D017978:Receptors, Growth Factor / Q000235:genetics; D015398:Signal Transduction; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C000715470:MAS1 protein, human; D008562:Membrane Glycoproteins; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D017978:Receptors, Growth Factor; C109148:SPINT2 protein, human; D014360:Trypsin Inhibitor, Kunitz Soybean; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met