LY294002 and sorafenib as inhibitors of intracellular survival pathways in the elimination of human glioma cells by programmed cell death

Abstract

Gliomas are aggressive brain tumors with very high resistance to chemotherapy throughout the overexpression of multiple intracellular survival pathways. Therefore, the aim of the present study was to investigate for the first time the anticancer activity of LY294002, phosphatidylinositol 3-kinase (PI3K) inhibitor and sorafenib, and rapidly accelerated fibrosarcoma kinase (Raf) inhibitor in the elimination of human glioma cells by programmed cell death. MOGGCCM (anaplastic astrocytoma, III) and T98G (glioblastoma multiforme, IV) cell lines incubated with LY294002 and/or sorafenib were used in the experiments. Simultaneous treatment with both drugs was more effective in the elimination of cancer cells on the way of apoptosis with no significant necrotic effect than single application. It was correlated with decreasing the mitochondrial membrane potential and activation of caspase 3 and 9. The expression of Raf and PI3K was also inhibited. Blocking of those kinases expression by specific siRNA revealed significant apoptosis induction, exceeding the level observed after LY294002 and sorafenib treatment in non-transfected lines but only in MOGGCCM cells. Our results indicated that combination of LY294002 and sorafenib was very efficient in apoptosis induction in glioma cells. Anaplastic astrocytoma cells turned out to be more sensitive for apoptosis induction than glioblastoma multiforme after blocking PI3K and Raf expression with siRNA.

Furanocoumarins as Enhancers of Antitumor Potential of Sorafenib and LY294002 toward Human Glioma Cells In Vitro

“…Interestingly, our studies showed that anaplastic astrocytoma cells were more resistant to induction-programmed cell death by sorafenib in combination with furanocoumarins compared to glioblastoma multiforme. The obtained results indicate that combination therapy using sorafenib may be more effective in gliomas with higher stages of malignancy, which is consistent with previous reports, according to which the use of an inhibitor simultaneously with quercetin, lensoside Aβ, and LY294002 was more effective in GBM compared to AA [31][32][33][34].…”

“…In the T98G line, we also noted a much higher pro-apoptotic effectiveness of the simultaneous application of sorafenib with imperatorin, which can be explained by a decrease in the level of procaspase 3 and an increase in the activity of caspase 3. Our previous studies also showed that sorafenib significantly reduced RAF kinase levels [34]. It is known that RAF, through its ability to activate proteins from the IAP family (inhibitors of apoptosis), responsible for inactivating caspases, inhibits apoptosis.…”

“…Furanocoumarins as well as LY294002 (PI3K inhibitor; Sigma, St. Louis, MO, USA) and sorafenib (Raf inhibitor; Nexavar; BAY 43-9006) were dissolved in DMSO and the final concentration of the solvent did not exceed 0.01% both in control and treated cells. Furanocoumarin concentrations were chosen experimentally and inhibitor doses were based on previous studies [33,34] and applied to the culture medium of MOGGCCM and T98G cells for 24 h.…”

“…The analysis of type and level of cellular death in the control and tested cultures (OLN-93, MOGGCCM, and T98G cells) was evaluated using fluorochrome staining, Hoechst 33342 (Sigma, St. Louis, MO, USA) and propidium iodide (Sigma, St. Louis, MO, USA) mix for apoptosis and necrosis and orange acridine for autophagy were used according to our previous studies [34]. Using a confocal microscope (Axiovert 200 M with scanning head LSM 5 PASCAL; Zeiss, Jena, Germany), dead cells were analyzed morphologically.…”

NUCKS1 promotes the progression of colorectal cancer via activating PI3K/AKT/mTOR signaling pathway

“…erefore, we examined the expression levels of p-AKT, p-mTOR, and p-4EBP1. LY294002 is a speci c inhibitor of the PI3K/AKT pathway [57]. In this study, when we used LY294002 to inhibit p-AKT levels in NUCKS1-overexpressing CRC cells, cell proliferation was decreased, and cell apoptosis and autophagy were both increased compared to levels in untreated NUCKS1overexpressing CRC cells.…”