No abstract

The senescence-associated secretory phenotype (SASP) can be provoked by side effects of therapeutic agents, fueling advanced complications including cancer resistance. However, the intracellular signal network supporting initiation and development of the SASP driven by treatment-induced damage remains unclear. Here we report that the transcription factor Zscan4 is elevated for expression by an ATM-TRAF6-TAK1 axis during the acute DNA damage response and enables a long term SASP in human stromal cells. Further, TAK1 activates p38 and PI3K/Akt/mTOR to support the persistent SASP signaling. As TAK1 is implicated in dual feedforward mechanisms to orchestrate the SASP development, pharmacologically targeting TAK1 deprives cancer cells of resistance acquired from treatment-damaged stromal cells in vitro and substantially promotes tumour regression in vivo. Together, our study reveals a novel network that links functionally critical molecules associated with the SASP development in therapeutic settings, thus opening new avenues to improve clinical outcomes and advance precision medicine.

Malignant gliomas are the most common malignant primary brain tumors and one of the most challenging forms of cancers to treat. Despite advances in conventional treatment, the outcome for patients remains almost universally fatal. This poor prognosis is due to therapeutic resistance and tumor recurrence after surgical removal. However, over the past decade, molecular targeted therapy has held the promise of transforming the care of malignant glioma patients. Significant progress in understanding the molecular pathology of gliomagenesis and maintenance of the malignant phenotypes will open opportunities to rationally develop new molecular targeted therapy options. Recently, therapeutic strategies have focused on targeting pro-growth signaling mediated by receptor tyrosine kinase/RAS/phosphatidylinositol 3-kinase pathway, proangiogenic pathways, and several other vital intracellular signaling networks, such as proteasome and histone deacetylase. However, several factors such as cross-talk between the altered pathways, intratumoral molecular heterogeneity, and therapeutic resistance of glioma stem cells (GSCs) have limited the activity of single agents. Efforts are ongoing to study in depth the complex molecular biology of glioma, develop novel regimens targeting GSCs, and identify biomarkers to stratify patients with the individualized molecular targeted therapy. Here, we review the molecular alterations relevant to the pathology of malignant glioma, review current advances in clinical targeted trials, and discuss the challenges, controversies, and future directions of molecular targeted therapy.