Genotoxic Stress Induces Senescence-Associated ADAM10-Dependent Release of NKG2D MIC Ligands in Multiple Myeloma Cells

Abstract

Genotoxic stress can promote antitumor NK cell responses by upregulating the surface expression of activating ligands on cancer cells. Moreover, a number of studies suggested a role for soluble NK group 2D ligands in the impairment of NK cell tumor recognition and killing. We investigated whether genotoxic stress could promote the release of NK group 2D ligands (MHC class I-related chain [MIC]A and MICB), as well as the molecular mechanisms underlying this event in human multiple myeloma (MM) cells. Our results show that genotoxic agents used in the therapy of MM (i.e., doxorubicin and melphalan) selectively affect the shedding of MIC molecules that are sensitive to proteolytic cleavage, whereas the release of the short MICA*008 allele, which is frequent in the white population, is not perturbed. In addition, we found that a disintegrin and metalloproteinase 10 expression is upregulated upon chemotherapeutic treatment both in patient-derived CD138(+)/CD38(+) plasma cells and in several MM cell lines, and we demonstrate a crucial role for this sheddase in the proteolytic cleavage of MIC by means of silencing and pharmacological inhibition. Interestingly, the drug-induced upregulation of a disintegrin and metalloproteinase 10 on MM cells is associated with a senescent phenotype and requires generation of reactive oxygen species. Moreover, the combined use of chemotherapeutic drugs and metalloproteinase inhibitors enhances NK cell-mediated recognition of MM cells, preserving MIC molecules on the cell surface and suggesting that targeting of metalloproteinases in conjunction with chemotherapy could be exploited for NK cell-based immunotherapeutic approaches, thus contributing to avoid the escape of malignant cells from stress-elicited immune responses

Genotoxic stress modulates the release of exosomes from multiple myeloma cells capable of activating NK cell cytokine production: Role of HSP70/TLR2/NF-kB axis

“…22 The 51 Cr-release assay was used to measure cytotoxic activity against K562 target cells, as described previously. 68 Cell proliferation of SKO-007(J3) cells was evaluated as follow: BrdU (20 mM) was added to the culture for 7 h, cells were harvested, fixed in a solution containing 30% methanol, 4% PFA.…”

“…The BM aspirates were processed, as described previously. 19,22 In some experiments, myeloma cells were purified using anti-CD138 magnetic beads (Miltenyi Biotec, Auburn, CA). 19,22 More than 95% of the purified cells expressed CD138 and CD38.…”

“…17,18 More recently, low doses of chemotherapeutic drugs have been shown to induce immunogenic senescence and stimulate NK cell-mediated recognition and clearance of drugtreated tumor cells via the upregulation of NKG2D and DNAM-1 activating ligands on the surface of cancer cells. [19][20][21][22] An outstanding question concerns the role of tumor-derived exosomes (Tex) on the modulation of NK cell-mediated functions. The available evidence points to the molecular composition of the exosome cargo as a major determinant of the immunoregulatory activity of Tex on NK cells pointing to a prevailing, although not exclusive, inhibitory role.…”

p38 MAPK differentially controls NK activating ligands at transcriptional and post-transcriptional level on multiple myeloma cells

“…Regulation of NKG2D and DNAM-1 ligand expression mainly occurs at transcriptional level. Additional mechanisms operate at the post-transcriptional level including inhibition of mRNA translation by cellular or viral microRNAs (miRNAs), ubiquitin-dependent proteasomal degradation, exosomal excretion, and proteolytic shedding from cell surface ( 2,13 ). Relevant signaling pathways involved in the induction of the NKG2D and DNAM-1 ligand expression include stress pathways, such as DNA damage and heat shock response ( 8,14,15 ), proliferative pathways, generated mainly by oncogene activation ( 16,17 ), and tumor suppressor pathways, where the p53 protein is a key regulator.…”

Teraphtal (sodium salt of cobalt 4,5-carboxyphthalocyanine) Decreases Sensitivity of Tumor Cells to Anthracycline Antibiotics and Mitoxantrone in Vitro

“…В отличие от стандартных АА в присутствии ACLA, не способного вызывать разрывы ДНК [23,24], в опухо-левых клетках запускается только процесс апоптоза и/или некроза [34]. Фенотип SLC индуцируется при воздействии DOX, DNR как в нормальных [35,36], так и в опухолевых клетках различного гистогенеза [29,[37][38][39], включая гемопоэтическое происхождение [31,32,40,41]. Для клеток с фенотипом SLC характерны морфологические (увеличение размера, разбухание ядер, появление микроядер) и биохимические (уве-личение активности β-галактозидазы лизосом) при-знаки и сохранение жизнеспособности [29].…”