A mouse model for pain and neuroplastic changes associated with pancreatic ductal adenocarcinoma

Abstract

Pancreatic ductal adenocarcinoma (PDAC) continues to be one of the deadliest human malignancies and is associated with excruciating pain, which is a serious complication and severely impacts the quality of life in patients. In human patients, poor survival prognosis is linked to remarkable remodeling of intrapancreatic nerves, which, in turn, is correlated to increased pain intensity. Understanding mechanisms underlying pain associated with PDAC has been hampered by the lack of animal models which replicate all germane aspects of the disease and importantly, enable analyses of pain associated with PDAC. In this study, we describe an immunocompetent orthotopic mouse model of PDAC involving intrapancreatic growth of K8484 mouse PDAC cells, which reliably exhibits a large number of key characteristics of human PDAC, including its unique histopathology and neuroplastic changes. We observed that tumor-bearing mice demonstrated significant abdominal mechanical hypersensitivity to von Frey stimuli as well as on-going pain in the conditioned place preference paradigm. Moreover, a myriad of other behavioral tests revealed that indicators of overall well-being were significantly reduced in tumor-bearing mice as compared to sham mice. Morphological and immunohistochemical analyses revealed structural remodeling in several different types of sensory and autonomic nerve fibers. Finally, perineural invasion of tumor cells, a cardinal manifestation in human PDAC, was also observed in our orthotopic mouse model. Thus, we describe a validated tumor model for quantitatively testing hypersensitivity and pain in PDAC, which lays a crucial basis for interrogating tumor-nerve interactions and the molecular and cellular mechanisms underlying pain in PDAC.

Cellular and molecular mechanisms of perineural invasion of pancreatic ductal adenocarcinoma

“…Subsequent studies addressed the specific regulatory role of PNI in cancer‐associated pain through several animal models. For example, a PDAC orthotopic K8484 mouse model showed the main characteristics of human PDAC, including the structural remodeling of histopathology and nerve fibers [ 117 ]. In vivo methods to quantify pain or hypersensitivity are important to understanding the molecular mechanism of pain and its impact on the process of PDAC [ 117 ].…”

“…For example, a PDAC orthotopic K8484 mouse model showed the main characteristics of human PDAC, including the structural remodeling of histopathology and nerve fibers [ 117 ]. In vivo methods to quantify pain or hypersensitivity are important to understanding the molecular mechanism of pain and its impact on the process of PDAC [ 117 ]. Of note, PHA‐848125, a dual inhibitor of cyclin‐dependent kinase and NTRK1, has been tested in preclinical trials to suppress PNI and alleviated pain generation in human PDAC cancer cells (BXPC3, MiaPACA2, and CAPAN1) in a xenograft mouse model [ 118 ].…”

CXCL10 and CCL21 Promote Migration of Pancreatic Cancer Cells Toward Sensory Neurons and Neural Remodeling in Tumors in Mice, Associated With Pain in Patients

“…The orthotopic mouse model of PDAC involving K8484 cells injection in C57BL/6 mice was employed as described previously. 10 Antibodies neutralizing CCL21 (10 mg/injection; or control IgG; twice weekly), CXCL10 (30 mg/injection; or control monoclonal IgG 2A; twice weekly), CCR7 (4 mg/injection; or control IgG; every other day), or a CXCR3 antagonist AMG487 (0.4 mg/injection; or vehicle; every other day) were injected intraperitoneally (Supplementary Table 1) for the duration specified in the Results.…”

Animal Models of Cancer-Related Pain: Current Perspectives in Translation

“…Spontaneous pain behavior is one of the most difficult components of cancer pain to manage and is therefore the most consistent end point against which the efficacy of a candidate drug is tested. The major limitation to using spontaneous pain as the end point is that the methodology differs substantially in the literature; spontaneous cancerrelated pain has been measured indirectly using hunching (Lindsay et al, 2005a;Sevcik et al, 2006;Stopczynski et al, 2014;Wang et al, 2017;Kajiwara et al, 2020), open field activity (Stopczynski et al, 2014;Selvaraj et al, 2017;Hirth et al, 2020), home cage activity (Selvaraj et al, 2017;Hirth et al, 2020), voluntary wheel running (Selvaraj et al, 2017), vocalizations (Lindsay et al, 2005a;Sevcik et al, 2006), conditioned place preference (Selvaraj et al, 2017) as well as impressions of appearance [e.g., grimace scale (Kajiwara et al, 2020), coat condition (Roughan et al, 2004a)]. While many of these (King et al, 2007;King et al, 2008;Hald et al, 2009b;Ungard et al, 2014;Gdowski et al, 2017;Remeniuk et al,…”

“…Home cage activity, open field activity, hunching, vocalizations, grimace, wheel running, CPP (Selvaraj et al, 2017;Wang et al, 2017) CIPN Mechanical Von frey, randall-selitto (Casals-Diaz et al, 2009;Han et al, 2018;Kyte et al, 2018;Laumet et al, 2019;Luo et al, 2019;Ma et al, 2019;Shahid et al, 2019;Bruna et al, 2020) Thermal Hargreaves, hot plate, acetone, cold plantar test (Chine et al, 2019;Luo et al, 2019;Shahid et al, 2019;Tonello et al, 2019;Bruna et al, 2020) Functioninduced Sensory and motor nerve conduction, functional autonomic tests, rota-rod, gait analysis (Liu et al, 2018;Laumet et al, 2019;Luo et al, 2019;Bruna et al, 2020)…”