Comparative proteomic profiling of triple-negative breast cancer reveals that up-regulation of RhoGDI-2 is associated to the inhibition of caspase 3 and caspase 9.
There are no targeted therapeutic modalities for triple-negative breast cancer (TNBC), thus it is associated with poor prognosis and worst clinical outcome. Here, our aim was to identify deregulated proteins in TNBC with potential therapeutic applications. Proteomics profiling of TNBC and normal breast tissues through two-dimensional electrophoresis and ESI-MS/MS mass spectrometry revealed the existence of 16 proteins (RhoGDI-2, HSP27, SOD1, DJ1, UBE2N, PSME1, FTL, SH3BGRL, and eIF5A-1) with increased abundance in carcinomas. We also evidenced for the first time the deregulation of COX5, MTPN and DB1 proteins in TNBC that may represent novel tumor markers. Particularly, we confirmed the overexpression of the Rho-GDP dissociation inhibitor 2 (RhoGDI-2) in distinct breast cancer subtypes, as well as in metastatic cell lines derived from lung, prostate, and breast cancer. Remarkably, targeted disruption of RhoGDI-2 by RNA interference induced mitochondrial dysfunction, and facilitated caspase-3 and -9 activation in two breast cancer cell lines. Moreover, suppression of RhoGDI-2 resulted in a robust sensitization of breast cancer cells to cisplatin therapy. In conclusion, we identified novel proteins deregulated in TNBC, and confirmed the overexpression of RhoGDI-2. We propose that RhoGDI-2 inhibition may be exploited as a potential therapeutic strategy along cisplatin-based chemotherapy in breast cancer.


CONCLUSIONS
There are no useful biomarkers neither targeted therapeutic modalities for triple-negative breast cancer, which highly contributes to the poor prognosis of this breast cancer subtype. In this work, we used two-dimensional electrophoresis and ESI-MS/MS spectrometry to identify novel deregulated proteins in breast cancer tissues. Particularly, our results showed that RhoGDI-2, a protein that has been associated to metastasis and poor survival in human cancers, is overexpressed in different subtypes of breast tumors, as well as in metastatic cell lines derived from lung, prostate, and breast cancer. Our data also provided novel insights about the role of RhoGDI-2 in apoptosis through intrinsic pathway inhibition. Importantly, they suggested that targeted modulation of RhoGDI-2 levels might be a useful strategy for breast cancer therapy.
Oncogenomics and Cancer Proteomics Laboratory, Autonomous University of Mexico City, Mexico.
Marcos A
MA
Muñiz Lino
Oncogenomics and Cancer Proteomics Laboratory, Autonomous University of Mexico City, Mexico.
Yadira
Y
Palacios-Rodríguez
Institute of Breast Diseases - FUCAM, Mexico City, Mexico.
Sergio
S
Rodríguez-Cuevas
Institute of Breast Diseases - FUCAM, Mexico City, Mexico.
Verónica
V
Bautista-Piña
Molecular Biomedicine Program and Biotechnology Network, National School of Medicine and Homeopathy, National Polytechnic Institute, Mexico City, Mexico.
Laurence A
LA
Marchat
Translational Medicine Laboratory, National Institute of Cancerology, Mexico City, Mexico.
Erika
E
Ruíz-García
Laboratory of Translational Cancer Research and Cellular Therapy, Oncology Hospital, Medical Center Siglo XXI, Mexico City, Mexico.
Horacio
H
Astudillo-de la Vega
Oncogenomics and Cancer Proteomics Laboratory, Autonomous University of Mexico City, Mexico.
Ana E
AE
González-Santiago
Oncogenomics and Cancer Proteomics Laboratory, Autonomous University of Mexico City, Mexico.
Ali
A
Flores-Pérez
Carcinogenesis Laboratory, National Institute of Cancerology, Mexico City, Mexico.
José
J
Díaz-Chávez
Lung Cancer Laboratory, National Institute of Respiratory Diseases, Mexico City, Mexico.
Ángeles
Á
Carlos-Reyes
Oncogenomics and Cancer Proteomics Laboratory, Autonomous University of Mexico City, Mexico.
Elizbeth
E
Álvarez-Sánchez
Oncogenomics and Cancer Proteomics Laboratory, Autonomous University of Mexico City, Mexico. Electronic address: genomicas@yahoo.com.mx.
César
C
López-Camarillo
D000328:Adult; D017209:Apoptosis; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism*; D053453:Caspase 9 / Q000378:metabolism*; D061945:Caspase Inhibitors / Q000737:chemistry*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000737:chemistry; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D061986:MCF-7 Cells; D013058:Mass Spectrometry; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism; D009362:Neoplasm Metastasis; D010455:Peptides / Q000737:chemistry; D020543:Proteome; D040901:Proteomics; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D064726:Triple Negative Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D015854:Up-Regulation; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta / Q000737:chemistry*
D061945:Caspase Inhibitors; D010455:Peptides; D020543:Proteome; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D002945:Cisplatin
Apoptosis; Caspases activation; Mitochondrial dysfunction; Proteomic profiling; RhoGDI-2; Triple-negative breast cancer