TRPV1 inhibition overcomes cisplatin resistance by blocking autophagy-mediated hyperactivation of EGFR signaling pathway.

Cisplatin resistance along with chemotherapy-induced neuropathic pain is an important cause of treatment failure for many cancer types and represents an unmet clinical need. Therefore, future studies should provide evidence regarding the mechanisms of potential targets that can overcome the resistance as well as alleviate pain. Here, we show that the emergence of cisplatin resistance is highly associated with EGFR hyperactivation, and that EGFR hyperactivation is arisen by a transcriptional increase in the pain-generating channel, TRPV1, via NANOG. Furthermore, TRPV1 promotes autophagy-mediated EGF secretion via Ca2+ influx, which activates the EGFR-AKT signaling and, consequentially, the acquisition of cisplatin resistance. Importantly, TRPV1 inhibition renders tumors susceptible to cisplatin. Thus, our findings indicate a link among cisplatin resistance, EGFR hyperactivation, and TRPV1-mediated autophagic secretion, and implicate that TRPV1 could be a crucial drug target that could not only overcome cisplatin resistance but also alleviate pain in NANOG+ cisplatin-resistant cancer.

Use of 3D Human Liver Organoids to Predict Drug-Induced Phospholipidosis.

Drug-induced phospholipidosis (PL) is a storage disorder caused by the formation of phospholipid-drug complexes in lysosomes. Because of the diversity of PL between species, human cell-based assays have been used to predict drug-induced PL in humans. We established three-dimensional (3D) human liver organoids as described previously and investigated their liver characteristics through multiple analyses. Drug-induced PL was initiated in these organoids and in monolayer HepG2 cultures, and cellular changes were systemically examined. Organoids that underwent differentiation showed characteristics of hepatocytes rather than HepG2 cells. The organoids also survived under PL-inducing drug conditions for 48 h and maintained a more stable albumin secretion level than the HepG2 cells. More cytoplasmic vacuoles were observed in organoids and HepG2 cells treated with more potent PL-induced drugs, but to a greater extent in organoids than in HepG2 cells. Lysosome-associated membrane protein 2, a marker of lysosome membranes, showed a stronger immunohistochemical signal in the organoids. PL-distinctive lamellar bodies were observed only in amiodarone-treated organoids by transmission electron microscopy. Human liver organoids are thus more sensitive to drug-induced PL and less affected by cytotoxicity than HepG2 cells. Since PL is a chronic condition, these results indicate that organoids better reflect metabolite-mediated hepatotoxicity in vivo and could be a valuable system for evaluating the phospholipidogenic effects of different compounds during drug development.

Evaluation of Circulating MicroRNA Biomarkers in the Acute Pancreatic Injury Dog Model.

This study aimed to evaluate the usefulness of four microRNAs (miRNAs) in an acute pancreatic injury dog model. Acute pancreatitis was induced by infusion of cerulein for 2 h (7.5 µg/kg/h). The levels of well-known miRNAs, microRNA-216a (miR-216a) and microRNA-375 (miR-375), and new candidates microRNA-551b (miR-551b), and microRNA-7 (miR-7), were measured at 0, 0.5, 1, 2, 6, 12, and 24 h with serum amylase and lipase, and histopathological examination was performed. Among the four miRNAs, miR-216a and miR-375, and serum enzymes were significantly increased by cerulein treatment. The expression levels of miRNAs and serum enzymes peaked at 2⁻6 h with a similar pattern; however, the overall increases in miR-216a and miR-375 levels were much higher than those of the serum enzyme biomarkers. Increased levels of miR-216a and miR-375 were most highly correlated to the degree of individual histopathological injuries of the pancreas, and showed much greater dynamic response than serum enzyme biomarkers. Twenty-four-hour time-course analysis in this study revealed time-dependent changes of miRNA expression levels, from initial increase to decrease by predose level in acute pancreatitis. Our findings demonstrate that, in dogs, miR-216a and miR-375 have the potential to sensitively detect pancreatitis and reflect well the degree of pancreatic injury, whereas miR-551b and miR-7 do not.

EZH2 Expression in Naturally Occurring Canine Tumors.

Enhancer of zeste homolog 2 (EZH2) shows upregulated expression in tumors and is an important driver of tumor development and progression. However, the mechanism underlying the mediation of tumor aggressiveness by EZH2 remains unclear. We here investigated the levels of EZH2 in various normal and tumorous dog tissues and compared these patterns with those of the corresponding human tissues. Immunohistochemical analysis showed positive staining for EZH2 in 76 of 82 cases of canine tumors, whereas low or negligible staining occurred in normal tissues and other canine tumors, including hepatocellular adenoma and lipoma. In particular, canine lymphoma, melanoma, basal cell tumors, squamous cell carcinoma, and prostate cancer all show EZH2 overexpression, as do their human counterparts. Given the similarities of spontaneous canine tumors to human cancers, we believe that these canine tumors can be used as animal models in future research and clinical trials in the development of EZH2 inhibitors.

Differential perturbation of the interstitial cystitis-associated genes of bladder and urethra in rat model.

Interstitial cystitis (IC) is a chronic bladder dysfunction characterized as urinary frequency, urgency, nocturia, and pelvic pain. The changes in urethra may wind up with the bladder changes in structure and functions, however, the functions of the urethra in IC remains elusive. The aim of this study was to understand the perturbed gene expression in urethra, compared with urinary bladder, associated with the defected urodynamics. Using female IC mimic rats, a comprehensive RNA-sequencing combined with a bioinformatics analysis was performed and revealed that IC-specific genes in bladder or urethra. Gene ontology analysis suggested that the cell adhesion or extracellular matrix regulation, intracellular signaling cascade, cardiac muscle tissue development, and second messenger-mediated signaling might be the most enriched cellular processes in IC context. Further study of the effects of these bladder- or urethra-specific genes may suggest underlying mechanism of lower urinary tract function and novel therapeutic strategies against IC.