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

Zając A,Rzeski W,Maciejczyk A,Jakubowicz-Gil J,Wertel I,Langner E,Sumorek-Wiadro J

doi:10.1007/s00441-021-03481-0

Zając A, Rzeski W + Show 5 more

Open Access

https://doi.org/10.1007/s00441-021-03481-0

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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.

Highlights

Anaplastic astrocytoma (AA, WHO grade III) and glioblastoma multiforme (GBM, WHO grade IV) are the most malignant, primary brain cancers
In the case of Beclin-1 in MOGGCCM cells (Fig. 4a), significant increase in the protein expression was observed after separate LY294002 and sorafenib incubation
In T98G cells, single and simultaneous application of LY294002 and sorafenib increased the level of caspase 3 expression, but in the case of sorafenib alone, the effect was not significant (Fig. 4d)

Summary

Introduction

Anaplastic astrocytoma (AA, WHO grade III) and glioblastoma multiforme (GBM, WHO grade IV) are the most malignant, primary brain cancers. They are characterized by aggressive growth, invasive infiltration into healthy brain tissue, and poor prognosis. There has been standard chemotherapy of malignant gliomas based on cytostatics with methylating properties, such as temozolomide, procarbazine, dacarbazine, or streptozotocine. Their alkylating activity should lead to elimination of the glioma cells upon the cell cycle arrest and apoptotic or autophagic cell death. Apoptosis is a defense mechanism that leads to elimination of transformed, infected, or damaged cells, and its induction causes to the activation of caspases (proteases— exist in cells by normal conditions as inactive pro-forms)

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