FasR and FasL in colorectal cancer

Abstract

Colorectal cancer (CRC) is one of the most common solid organ cancers prevalent worldwide causing, in spite of advancing therapeutic methodology, high rate of patient mortality, especially due to metastasis development. The cancer stem cell (CSC) theory of tumor growth indicates that CSCs within the tumor mass have great capacity to initiate and sustain tumor growth. Following the suggestion that Fas signaling can be engaged in apoptosis, tumor maintenance, senescence or DICE (death induced by CD95 or CD95L elimination), the attempts to broaden the knowledge concerning the relationships between CSCs features and FasR/FasL appeared to be necessary. The most important advantage of our study was the simultaneously analysis of CSCs from commonly used CRC lines (HCT116 and HT29) and tumor fragments collected from CRC patients. Moreover, the sphere-promoting expansion of CRC lines brought a specific three-dimensional specific environment for CSC exploration. We further investigated the function of Fas signaling in CRC lines depending on the culture mode as we incubated HCT116 and HT29 cells with anti-FasR agonistic antibodies. It appeared to act in a line-dependent and culture mode-dependent manner and influenced some particular features of CSCs such as spherogenicity, proliferation and phenotype. Additionally, the analysis of mRNA level showed that disease progression is associated with significantly increased expression of FasR and/or FasL. In conclusion, our observation seems to confirm that spherical model of cancer lines is more reliable for some sophisticated analysis because of their greater resemblance to the CSCs from human CRC samples in comparison to commonly used adherent cells, at least according to aspects of their biology analyzed in this study. That can be extended to the resemblance of in vitro sphere forming conditions to the in vivo environment. However, the greatest difference concerns the level of apoptosis, thus, this issue require further experiments.

Cancer stem cells as targets for DC-based immunotherapy of colorectal cancer

“…As we reported earlier 36 , the adherent forms of the studied HCT116 and HT29 CRC cell lines are characterized by 100%-enrichment in CD133 + CD44 + CD29 + CSCs, however, when the culture conditions were modified into sphere-forming environment, a decrease of CD133 + cells number by 39% and 59% in HCT116 and HT29 cell cultures, respectively, was found. CRC patients-derived spherical cultures appeared to contain varying proportions of CD133 + cells (ranging from 2 to 96%).…”

“…Primary colon spheroid cultures (SC) were treated as we described previously 36 . Briefly, SCs were maintained on low adherent culture flasks and plates in serum-free stem cell medium containing DMEM-F12 supplemented with ITS Liquid Media Complement (1x), BSA (4 mg/ml), glucose (3 ml/ml), Hepes (5 mM), L-glutamine (2 mM), progesterone (20 nM), putrescine (9.6 µg/ml), Heparin (4 μg/ml), EGF (20 ng/ml), bFGF (20 ng/ml), and antibiotic-antimycotic solution (1x).…”

“…It was reported that spheroid (3-D) cultures of cancer cell lines better than adherent (2-D) cell cultures resemble original cancer in such areas as gene expression profiles, cellular heterogeneity, morphology and distribution of cancer cells 36 – 42 . These aspects of cancer cells biology primarily depend on the access to oxygen, nutrients and growth factors.…”

“…However, some other groups showed independently that CD133 − cells also possess high proliferative and differentiating potential, comparable to those of CD133 + CRC-CSCs 4 , 61 . Proteins which are also considered as reliable CSCs markers are CD24, CD29, CD44, CD166, Aldh1 and other 36 , 37 , 62 , 63 .…”

In vitro characterization of spheres derived from colorectal cancer cell lines

“…Cells harboring KRAS mutations within codon 13 are reported to possess high oncogenic potential and be very aggressive (73). Additionally, KRAS status has also biological relevance in terms of colorectal cancer clinical outcome to anti-EGFR therapy (74) and senescence and/or apoptosis mediated by Fasr/FasL (75,76). besides KRAS gene, HCT116 and HT29 cell lines represent different mutation status of chromosomal instability (CIN) phenotype and some cancer critical genes such as BRAF, PIK3CA and TP53 genes (70).…”