Mutant KRAS modulates colorectal cancer cells invasive response to fibroblast-secreted factors through the HGF/C-MET axis
Authors: Carvalho Patrícia Dias , Martins Flávia , Mendonça Susana , Ribeiro Andreia , Machado Ana Luísa , Carvalho Joana , Oliveira Maria José , Velho Sérgia 
Published: November 2021

AbstractGenetic alterations influence the malignant potential of cancer cells, and so does the tumor microenvironment. Herein, we combined the study of KRAS oncogenic effects in colorectal cancer cells with the influence of fibroblasts-derived factors. Results revealed that mutant KRAS regulates cell fate through both autonomous and non-autonomous signaling mechanisms. Specifically, processes such as proliferation and cell-cell aggregation were autonomously controlled by mutant KRAS independently of the stimulation with fibroblasts conditioned media. However, cancer cell invasion revealed to be a KRAS-dependent non-autonomous effect, resulting from the cooperation between fibroblasts-derived HGF and mutant KRAS regulation of C-MET expression. C-MET downregulation upon KRAS silencing rendered cells less responsive to HGF and thus less invasive. Yet, in one cell line, KRAS inhibition triggered invasion upon stimulation with fibroblasts conditioned media. Inhibition of PIK3CA oncogene did not promoted invasion, thus showing a KRAS-specific effect. Moreover, the invasive capacity also depended on the HGF-C-MET axis. Overall, our study awards oncogenic KRAS an important role in modulating the response to fibroblast-secreted factors either by promoting or impairing invasion, and depicts the HGF-C-MET axis as a putative therapeutic target to impair the invasive properties of mutant KRAS cancer cells.SignificanceTargeting mutant KRAS cancers is an urgent clinical need. HGF-C-MET axis inhibition arises as a possible strategy to target mutant KRAS CRC, both primary and metastatic tumors.Additional informationFinancial supportThis work was supported through FEDER funds through the Operational Programme for Competitiveness Factors (COMPETE 2020), Programa Operacional de Competitividade e Internacionalização (POCI), Programa Operacional Regional do Norte (Norte 2020), European Regional Development Fund (ERDF), and by National Funds through the Portuguese Foundation for Science and Technology (FCT) (PTDC/MED-ONC/31354/2017). PDC is a PhD student from Doctoral Program in Pathology and Molecular Genetics from the Institute of Biomedical Sciences Abel Salazar (ICBAS, University of Porto) and she is funded through a PhD fellowship (SFRH/BD/131156/2017) awarded by the FCT. FM is a PhD student from Doctoral Program in Biomedicine from the Faculty of Medicine of the University of Porto and she is funded through a PhD fellowship (SFRH/BD/143669/2019) awarded by the FCT. SM is a PhD student from Doctoral Program in Biomedicine from the Faculty of Medicine of the University of Porto and she is funded through a PhD fellowship (SFRH/BD/143642/2019) awarded by the FCT. AR is a junior researcher hired by IPATIMUP under the CaTCh project funded by FEDER and FCT (POCI-01-0145-FEDER-031354). ALM is a PhD student from Doctoral Program in Biomedicine from the Faculty of Medicine of the University of Porto and she is funded through a PhD fellowship (2020.08932.BD) awarded by the FCT. MJO is principal researcher at INEB. SV is hired by IPATIMUP under norma transitória do DL n.º 57/2016 alterada pela lei n.º 57/2017.