The Ehrlich Tumor Induces Pain-Like Behavior in Mice: A Novel Model of Cancer Pain for Pathophysiological Studies and Pharmacological Screening

Abstract

The Ehrlich tumor is a mammary adenocarcinoma of mice that can be developed in solid and ascitic forms depending on its administration in tissues or cavities, respectively. The present study investigates whether the subcutaneous plantar administration of the Ehrlich tumor cells induces pain-like behavior and initial pharmacological susceptibility characteristics. The Ehrlich tumor cells (1 × 104–107 cells) induced dose-dependent mechanical hyperalgesia (electronic version of the von Frey filaments), paw edema/tumor growth (caliper), and flinches compared with the saline group between days 2 and 12. There was no difference between doses of cells regarding thermal hyperalgesia in the hot-plate test. Indomethacin (a cyclooxygenase inhibitor) and amitriptyline hydrochloride (a tricyclic antidepressant) treatments did not affect flinches or thermal and mechanical hyperalgesia. On the other hand, morphine (an opioid) inhibited the flinch behavior and the thermal and mechanical hyperalgesia. These effects of morphine on pain-like behavior were prevented by naloxone (an opioid receptor antagonist) treatment. None of the treatments affected paw edema/tumor growth. The results showed that, in addition to tumor growth, administration of the Ehrlich tumor cells may represent a novel model for the study of cancer pain, specially the pain that is susceptible to treatment with opioids, but not to cyclooxygenase inhibitor or to tricyclic antidepressant.

Synthesis and Cytotoxicity of Novel Analogues of Podophyllotoxin

“…The in vitro cell based cytotoxicity assay is a useful and reliable method to demonstrate the activity of chemotherapeutic drugs and also gives a prior knowledge of the efficacy of various agents before using in invivo [21].The Ehrlich Ascites tumor is a murine mammary adenocarcinoma which grows in mice by intra peritoneal passages. The ascitic form of the tumor is the chosen experimental model to evaluate the influence of various drugs on its proliferation and host interaction against the cancer cells [22].Hence we used the Ehrlich Ascites Tumor cells for in vitroexperiments. In order to assess the toxicity of the compounds and evaluate their base-line metabolic effects on the cell [23], the trypan blue dye exclusion method of testing the cytotoxicity of these novel drugs in vitroon murine mammary carcinoma (EAT) cells was done.…”

Natural killer activity of the spleen cells of Ehrlich tumor-bearing mice treated with Copaifera multijuga extract

“…Ehrlich tumor is a spontaneous murine mammary adenocarcinoma adapted to the ascitic form and inoculated in mice by serial intraperitoneal passages [9,10]. This tumor model is widely used in experimental cancer studies due to its versatility; it is able to adapt to an ascitic form when inoculated by the intraperitoneal route or a solid form when inoculated by the subcutaneous route [9,11,12].…”

The detection of curcumins’ antitumoral effects via argyrophilic nucleolar organizing region-associated protein synthesis in mice with ehrlich’s ascitic carcinoma

“…The Ehrlich ascites tumor cells are spontaneous murine mammary adenocarcinoma (6) and develop in almost all strains of mice as a rapidly growing carcinoma with very aggressive behavior (7). This tumor has similar features with human tumors and is sensitive to chemotherapy (8).…”

“…This tumor has similar features with human tumors and is sensitive to chemotherapy (8). Different studies indicated the benefi cial use of Ehrlich's ascitic carcinoma (EAC) and solid tumor (EST) models as a valuable tool in exploring biological activities in cancer and evaluating the effect of several chemical compounds (7,9,10).…”