Arachidonic acid drives adaptive responses to chemotherapy-induced stress in malignant mesothelioma

Abstract

Background High resistance to therapy and poor prognosis characterizes malignant pleural mesothelioma (MPM). In fact, the current lines of treatment, based on platinum and pemetrexed, have limited impact on the survival of MPM patients. Adaptive response to therapy-induced stress involves complex rearrangements of the MPM secretome, mediated by the acquisition of a senescence-associated-secretory-phenotype (SASP). This fuels the emergence of chemoresistant cell subpopulations, with specific gene expression traits and protumorigenic features. The SASP-driven rearrangement of MPM secretome takes days to weeks to occur. Thus, we have searched for early mediators of such adaptive process and focused on metabolites differentially released in mesothelioma vs mesothelial cell culture media, after treatment with pemetrexed. Methods Mass spectrometry-based (LC/MS and GC/MS) identification of extracellular metabolites and unbiased statistical analysis were performed on the spent media of mesothelial and mesothelioma cell lines, at steady state and after a pulse with pharmacologically relevant doses of the drug. ELISA based evaluation of arachidonic acid (AA) levels and enzyme inhibition assays were used to explore the role of cPLA2 in AA release and that of LOX/COX-mediated processing of AA. QRT-PCR, flow cytometry analysis of ALDH expressing cells and 3D spheroid growth assays were employed to assess the role of AA at mediating chemoresistance features of MPM. ELISA based detection of p65 and IkBalpha were used to interrogate the NFkB pathway activation in AA-treated cells. Results We first validated what is known or expected from the mechanism of action of the antifolate. Further, we found increased levels of PUFAs and, more specifically, arachidonic acid (AA), in the transformed cell lines treated with pemetrexed. We showed that pharmacologically relevant doses of AA tightly recapitulated the rearrangement of cell subpopulations and the gene expression changes happening in pemetrexed -treated cultures and related to chemoresistance. Further, we showed that release of AA following pemetrexed treatment was due to cPLA2 and that AA signaling impinged on NFkB activation and largely affected anchorage-independent, 3D growth and the resistance of the MPM 3D cultures to the drug. Conclusions AA is an early mediator of the adaptive response to pem in chemoresistant MPM and, possibly, other malignancies.

Butein-instigated miR-186-5p-dependent modulation of TWIST1 affects resistance to cisplatin and bioenergetics of Malignant Pleural Mesothelioma cells

“…EMT is an important feature of MPM, since mesothelial cells show a proclivity to undergo EMT even in pathophysiological conditions, such as peritoneal dialysis [45,46] . We and others showed that EMT sustains and accompanies a therapy-induced SASP which fuels the resistance of MPM cells to cisplatin and pemetrexed [11,14] . More recently, an EMT-omic signature emerged as s distinct prognostic trait of MPM [47] and as a determinant of anti-CTLA-4 immuno-response [11,14,39] .…”

“…We and others showed that EMT sustains and accompanies a therapy-induced SASP which fuels the resistance of MPM cells to cisplatin and pemetrexed [11,14] . More recently, an EMT-omic signature emerged as s distinct prognostic trait of MPM [47] and as a determinant of anti-CTLA-4 immuno-response [11,14,39] . TWIST1, being a key EMT player and a target of microRNA modulation by butein, may well find a place within the chemo-sensitizing actions of this versatile compound.…”

“…Cells were cultured in Ham’s F12 supplemented with L-glutamine 10% fetal calf serum (Gibco BRL, Grand Island, NY), 100 U/mL penicillin, and 100 µg/mL streptomycin in a humidified atmosphere containing 5% CO 2 at 37 °C. The human MPM cell lines MSTO-211H, NCI-H2373, and HP1 were described previously [ 12 ] . All cell lines were in-house tested for mycoplasma contamination by using a commercially available PCR-based assay (R&D Systems, Minneapolis, USA).…”

“…Ex vivo studies have shown that MPM cells are endowed with high resistance to therapy [10] ; therefore, attenuating such a process is an unmet need. We and others showed that specific rearrangement of cell subpopulations, sustained by the acquisition of a senescence-associated secretory phenotype (SASP), may underlie the emergence of MPM chemoresistance [11][12][13][14] . We found that a naturally occurring compound with pleiotropic functions, butein (20,40,3,4-tetrahydroxychalcone), interfered with the emergence of those chemoresistant aldehyde dehydrogenase-positive (ALDH pos ) cell subpopulations, by simultaneously blocking NFkB and STAT3 signaling [15,16] .…”

Tumor Glucose and Fatty Acid Metabolism in the Context of Anthracycline and Taxane-Based (Neo)Adjuvant Chemotherapy in Breast Carcinomas

“…Recent studies analysing the role of the arachidonic acid (AA), a representative PUFA in different tumors have found a link between AA and macrophage function in ovarian cancer and have demonstrated that high level of AA is associated with poor clinical outcome in ovarian cancers ( 133 ). Another recent study has presented that in chemoresistant malignant pleural mesothelioma AA is a mediator of the adaptive response to pemetrexed ( 134 )…”