Z-360, a Novel Therapeutic Agent for Pancreatic Cancer, Prevents Up-Regulation of Ephrin B1 Gene Expression and Phosphorylation of NR2B via Suppression of Interleukin-1β Production in a Cancer-Induced Pain Model in Mice

Abstract

BackgroundZ-360 is an orally active cholecystokinin-2 (CCK2)/gastrin receptor antagonist currently under development as a therapeutic drug for pancreatic cancer. It was previously reported that Z-360 treatment in combination with gemcitabine prolonged the survival period in a lethal pancreatic cancer xenograft model in mice. In a phase Ib/IIa clinical study, Z-360 treatment displayed a trend of reduced pain in patients with advanced pancreatic cancer in combination with gemcitabine including analgesics such as opioids. Here, we investigated the mechanism of analgesic action of Z-360 in a severe cancer-induced pain model in mice, which is considered to be opioid-resistant, by examining ephrin B1 gene expression, N-methyl-D-aspartate receptor NR2B subunit phosphorylation, and interleukin-1β (IL-1β) production.ResultsIn a mouse model of cancer-induced pain, ephrin B1 gene expression in dorsal root ganglia (DRGs) and the phosphorylation of NR2B in the spinal cord were induced. Z-360 treatment inhibited both ephrin B1 gene expression and the phosphorylation of NR2B. In addition, IL-1β production increased in the cancer-inoculated hind paw of mice, but could be suppressed by treatment with Z-360. Moreover, we observed that the CCK1 receptor antagonist devazepide similarly suppressed up-regulation of ephrin B1 gene expression and IL-1β production, and that the intraperitoneal injection of sulfated CCK-8 induced the production of IL-1β in the cancer-inoculated region.ConclusionsWe have identified a novel pain cascade, in which IL-1β production in cancer-inoculated regions induces ephrin B1 gene expression in DRGs and then ephrin B1 enhances the tyrosine phosphorylation of NR2B via Eph B receptor in the spinal cord. Notably, Z-360 relieves cancer-induced pain by preventing this pain cascade through the suppression of IL-1β production, likely via the blockade of CCK1 receptor. The pre-clinical results presented here support the analgesic action of Z-360 in pancreatic cancer patients with severe, opioid-resistant pain. Pre-clinical and clinical results have demonstrated that Z-360 combined with gemcitabine represents a promising pancreatic cancer therapy approach with characteristic analgesic effects in addition to the prolongation of survival.

EphBs: an integral link between synaptic function and synaptopathies

“…In models of cancer-induced pain, expression of ephrin-B1 and EphB1 are upregulated [85, 89, 90]. Here, the EphB-NMDAR interaction is also specifically implicated because blocking EphB1 signaling alleviates mechanical allodynia [85].…”

“…The changes in EphB and ephrin-B1 expression in cancer-induced pain are likely to be downstream of the inflammatory cytokines Interleukin-1 beta (IL-1β), Interleukin 6 (IL-6) and Tumor necrosis factor-alpha (TNF-α) [89]. Consistent with this, inhibiting the Cholecystokinin B receptor (CCK2)/gastrin receptor with a drug (Z-360) reduces IL-1β levels, prevents upregulation of ephrin-B1 expression, and reduces GluN2B phosphorylation [90]. The observation that blocking EphB1 activation alleviates morphine tolerance in models of bone cancer pain [85] suggests that modulating EphB signaling could provide an avenue for treating chronic pain.…”

“…Finally, JNK gets phosphorylated and activated, which phosphorylates p-38 and converges to activate ERK[86]. ( d ) Pathological cancer-induced pain shares a remarkable number of the same mechanisms with pathological central and peripheral pain[85, 89, 90]. Unique to cancer-induced pain is that src kinase directly phosphorylates ERK to activate gene transcription of c-fos [85].…”

“…Unique to cancer-induced pain is that src kinase directly phosphorylates ERK to activate gene transcription of c-fos [85]. Additionally, inflammatory cytokines TNFα, IL-6, and IL-1β are upregulated leading to hyperalgesia, and hyperexcitability of nerve afferents[89, 90]. …”

Principles in the design of ligand-targeted cancer therapeutics and imaging agents

“…For example, Z-360 is an orally deliverable CCKBR antagonist that has been used to target imaging agents and therapeutic agents to tumours that overexpress CCKBR 81 . Like most other antagonists, Z-360 is not endocytosed; nevertheless, successful therapy has been observed owing to the high tumour-specific expression of CCKBR that resulted in The design of ligand-targeted therapeutic agents commonly includes: a targeting ligand; a spacer; a cleavable bridge that is stable in circulation but that permits drug release following endocytosis into a target cell; and a therapeutic 'warhead'.…”