Midregion PTHrP regulates Rip1 and caspase expression in MDA-MB231 breast cancer cells.
It was previously reported that the midregion PTHrP domain (38-94)-amide restrains growth and invasion "in vitro", causes striking toxicity and accelerates death of some breast cancer cell lines, the most responsive being MDA-MB231 whose tumorigenesis was also attenuated "in vivo". In addition, we have demonstrated that midregion PTHrP is imported in the nucleoplasm of cultured MDA-MB231 cells, and that "in vitro" it can bind chromatin of metaphase spread preparations and also an isolated 20-mer oligonucleotide, thereby appearing endowed with a putative transcription factor-like DNA-binding ability. Here, we examined whether PTHrP (38-94)-amide was able to modulate the expression of genes encoding for apoptosis factors and caspases. Employing a combination of conventional and semi-quantitative multiplex PCR techniques, antisense oligonucleotide (asODN) transfections, proliferation/invasion assays and protein analyses, here we report that PTHrP treatment induces the up-regulation of Bcl-xS, Bad and Rip1 and switches-on the expression of caspase-2, -5, -6, -7 and -8 in MDA-MB231 cells. Moreover, we demonstrate for the first time that asODN-induced under-expression of Rip1 can lead to a more pronounced up-regulation of some caspases due, at least in part, to JNK inactivation, thus providing a new example of factor involved in the transcriptional regulation of the apoptotic enzymes.
Luparello
Claudio
C
Dipartimento di Biologia Cellulare e dello Sviluppo, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy. clupar@tin.it
Sirchia
Rosalia
R
Lo Sasso
Bruna
B
D017209:Apoptosis; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D009361:Neoplasm Invasiveness; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D044162:Parathyroid Hormone-Related Protein / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection; D051025:bcl-Associated Death Protein / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
C119724:AGFG1 protein, human; C494819:BAD protein, human; C494811:BCL2L1 protein, human; D028861:Nuclear Pore Complex Proteins; D016376:Oligonucleotides, Antisense; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments; D016601:RNA-Binding Proteins; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein; D048031:JNK Mitogen-Activated Protein Kinases; D020169:Caspases