Electroporation in Translational Medicine: From Veterinary Experience to Human Oncology.

Electroporation (EP) is a broadly accepted procedure that, through the application of electric pulses with appropriate amplitudes and waveforms, promotes the delivery of anticancer molecules in various oncology therapies. EP considerably boosts the absorptivity of targeted cells to anticancer molecules of different natures, thus upgrading their effectiveness. Its use in veterinary oncology has been widely explored, and some applications, such as electrochemotherapy (ECT), are currently approved as first-line treatments for several neoplastic conditions. Other applications include irreversible electroporation and EP-based cancer vaccines. In human oncology, EP is still mostly restricted to therapies for cutaneous tumors and the palliation of cutaneous and visceral metastases of malignant tumors. Fields where veterinary experience could help smooth the clinical transition to humans include intraoperative EP, interventional medicine and cancer vaccines. This article recapitulates the state of the art of EP in veterinary and human oncology, recounting the most relevant results to date.

Electrochemotherapy in Translational Medicine: From Veterinary Experience to Human Oncology.

Electrochemotherapy (ECT) is a tumor treatment that, through the application of electric pulses with suitable amplitude and waveforms, favors the systemic or local delivery of chemotherapy agents. This procedure significantly increases the permeability of cancer cells to anticancer drugs, making them more effective and allowing their use at lower doses with less morbidity for patients. Its use in veterinary oncology is consolidated and it is currently adopted as first-line treatment for different cancers with successful results. In human oncology, ECT use is mainly in the treatment of cutaneous tumors and for the palliation of cutaneous metastases of malignant tumors. A standard operating procedure has been formulated. Currently, several preclinical and phase I and II studies are under way involving various cancers in humans to better define the efficacy and tolerability of this therapy. This review summarizes the state of the art of ECT in veterinary and human oncology, describing the most significant results achieved to date.

Electrochemotherapy for the treatment of cutaneous solid tumors in equids: A retrospective study.

Background: Electrochemotherapy (ECT) promotes the increased uptake of antitumor agents through the administration of permeabilizing electric pulses, thus enhancing chemotherapy effectiveness. Aim: Our study aimed to describe the tolerability and efficacy of ECT alone or in association with surgery to manage solid neoplasms in equids. Methods: Medical records of equids with a diagnosis of malignant tumors treated with ECT alone or in combination with surgery were retrospectively evaluated. Each equid received local treatment within the tumors or the tumors' bed with cisplatin at the dose of 0.5 mg/cm2. Trains of permeabilizing biphasic electric pulses were then applied under spinal or general anesthesia. Results: Sixteen equids were enrolled in this study. There were nine melanoma cases, four fibrosarcoma, and three squamous cell carcinoma. Of those 16 equids, 7 received ECT for treatment of intraoperative local disease, while in 9 cases, ECT was the only treatment modality. The seven equids treated with the combination of ECT and surgery still have no evidence of disease at different times ranging from 9 to 60 months. The remaining nine had the following responses: two complete remissions, five partial responses, one stable disease, and one progressive disease. The treatment was well-tolerated, and local side effects were minimal. No systemic effects were documented. Conclusion: This retrospective study suggests that ECT may be beneficial for equids with solid neoplasms and could be a useful addition to the current therapeutic options considering its low cost, limited toxicity, and ease of administration.

Evaluation of electrochemotherapy in the management of apocrine gland anal sac adenocarcinomas in dogs: A retrospective study.

Background: Electrochemotherapy (ECT) combines the administration of anticancer drugs with the delivery of electric pulses, thus increasing the drug uptake through the cell membranes, resulting in increased efficacy. Aim: The aim of our study was to describe the tolerability and efficacy of ECT alone or in association with other treatment modalities for the management of apocrine gland anal sac adenocarcinoma (AGASAC). Methods: Medical records of dogs with a diagnosis of AGASAC that were treated with ECT alone or in combination with surgery/chemotherapy were retrospectively evaluated. Each dog received 20 mg/m2 of bleomycin intravenously. Based on the clinician's decision, the primary tumor or tumor bed was also infiltrated with cisplatin at the dose of 0.5 mg/cm2. Trains of permeabilizing biphasic electric pulses were then applied under general anesthesia. Results: Ten dogs were enrolled in the study. Of those 10 dogs, only one received ECT for treatment of microscopic local disease, while in six cases ECT was the only treatment modality. In three dogs, ECT was followed by systemic medical treatment. Six dogs (60%) had a partial response (PR), three dogs (30%) had stable disease, and one dog treated for microscopic disease did not show any sign of local relapse for 305 days after treatment, being still alive and in complete remission at the time of writing this article. The median time to progression was 303 days and the median survival time was 365 days. The treatment was well tolerated and local side effects were minimal. No systemic effects were documented. Conclusion: This preliminary study suggests that ECT may be beneficial for dogs with AGASAC and could be a useful addition to the current therapeutic options in consideration of its low cost, limited toxicity, and ease of administration.

Combination of bleomycin and cisplatin as adjuvant electrochemotherapy protocol for the treatment of incompletely excised feline injection-site sarcomas: A retrospective study.

Background: fFeline injection-site sarcomas (FISSs) are mesenchymal tumors that can occur in cats after injections of different medical agents and are easily prone to recurrence. Aim: The aims of this study were to report treatment outcomes for cats with feline injection-site sarcomas (FISSs) treated with both bleomycin and cisplatin, per adjuvant electrochemotherapy (ECT) protocol. Methods: The medical records of cats with a diagnosis of FISS that were treated with ECT using both bleomycin and cisplatin were retrospectively evaluated. A total of 27 cats were available for statistical evaluation of their response. The cats received intravenous 20 mg/m2 bleomycin, and the tumor bed and margins were infiltrated with cisplatin at the dose of 0.5 mg/cm2. Then, the trains of permeabilizing biphasic electric pulses lasting 50 + 50 µseconds each were delivered in bursts of 1,300 V/cm using caliper electrodes under sedation. A second session was performed 2 weeks later. Results: Side effects were limited to local inflammation in three cats. Three cats developed local tumor recurrence at days 180, 180, and 545 after surgery, two cats developed recurrence and metastases at 100 and 505 days after surgery, and two cats experienced distant metastases. A median time to recurrence could not be calculated as over 80% of the study population remained disease free or were censored due to death from other causes. Mean survival time was 985 days, and median cumulative survival for all cases was 1,000 days. Conclusion: When compared to historical controls, the results of this study demonstrate the superior rates of tumor-free survival and disease-free interval. This adjuvant therapy could be a useful addition to the current options for FISS in consideration of its efficacy, limited toxicity, and ease of administration.

Comparison of two different doses of bleomycin in electrochemotherapy protocols for feline cutaneous squamous cell carcinoma nonsegregated from ultraviolet light exposure.

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin tumors in cats due to chronic exposure to ultraviolet light. Local treatments such as electrochemotherapy (ECT) promote disease control or even complete remission. We hypothesize that cats could benefit from treatments using bleomycin at reduced dosages. A prospective nonrandomized single-blind study evaluated the clinical parameters, site lesion, staging, disease-free interval (DFI) and survival time by comparing the standard dose of bleomycin (15,000 UI/m2) (n = 22) with a reduced dose (10,000 UI/m2) (n = 34) in cats with cSCC that underwent ECT as the sole treatment modality. No statistically significant difference in DFI or overall survival was observed between the 2 groups. A higher DFI was found in cats with a small tumor size (less than 0.33 cm3) compared with that for cats with a large tumor size (P = 0.045). Furthermore, a reduced overall survival time for cats with a higher stage in the standard group SG (T3 and T4) (P = 0.004) was observed when compared to that for cats with a lower stage (T1 and T2). In conclusion, ECT using both doses of bleomycin may achieve the same response rate in terms of the overall response, DFI, and overall survival.

Definition of a Novel Plasmid-Based Gene Transfection Protocol of Mammalian Skeletal Muscles by Means of In Vivo Electroporation.

We describe an original electroporation protocol for in vivo plasmid DNA transfection. The right hind limbs of C57 mice are exposed to a specifically designed train of permeabilizing electric pulses by transcutaneous application of tailored needle electrodes, immediately after the injection of pEGFP-C1 plasmid encoding GFP (Green Fluorescente Protein). The electroporated rodents show a greater GFP expression than the controls at three different time points (4, 10, and 15 days). The electroporated muscles display only mild interstitial myositis, with a significant increase in inflammatory cell infiltrates. Finally, mild gait abnormalities are registered in electroporated mice only in the first 48 h after the treatment. This protocol has proven to be highly efficient in terms of expression levels of the construct, is easy to apply since it does not require surgical exposure of the muscle and is well tolerated by the animals because it does not cause evident morphological and functional damage to the electroporated muscle.

Adjuvant electrochemotherapy with bleomycin and cisplatin combination for canine soft tissue sarcomas: A study of 30 cases.

Electrochemotherapy (ECT) couples the administration of anticancer drugs with the delivery of electric pulses that increase the drug uptake through the cell membranes, thus resulting in an improved efficacy. This study has evaluated the tolerability and efficacy of the combination of systemic bleomycin and local cisplatin as ECT agents for incompletely excised canine soft tissue sarcoma (STS). Thirty dogs with incompletely excised STSs were enrolled. The dogs received intravenous 20 mg/m2 bleomycin, and the tumor bed and margins were infiltrated with cisplatin at the dose of 0.5 mg/cm2. Then, trains of permeabilizing biphasic electric pulses were applied under sedation. More precisely, 5 min after the injection of the chemotherapy agents, sequences of eight biphasic pulses lasting 50 + 50 µsec each, were delivered in bursts of 1,300 V/cm using caliper electrodes. A second session was performed 2 wk later. The treatment was well tolerated and side effects were minimal. Twenty-six dogs had no evidence of recurrence at the time of manuscript writing; four had recurrence and one of the four recurring dogs died of lung metastases. Median estimated disease free was 857 d. Perivascular wall tumors response was compared to that of the other STSs, but the difference in outcome was not significant. ECT using combination of bleomycin and cisplatin appears to be effective in the treatment of incompletely resected STSs in dogs. This therapeutic approach could be a useful addition to the current options in consideration of its low cost, limited toxicity, and ease of administration.

RIP1-HAT1-SIRT Complex Identification and Targeting in Treatment and Prevention of Cancer.

Purpose: Alteration in cell death is a hallmark of cancer. A functional role regulating survival, apoptosis, and necroptosis has been attributed to RIP1/3 complexes.Experimental Design: We have investigated the role of RIP1 and the effects of MC2494 in cell death induction, using different methods as flow cytometry, transcriptome analysis, immunoprecipitation, enzymatic assays, transfections, mutagenesis, and in vivo studies with different mice models.Results: Here, we show that RIP1 is highly expressed in cancer, and we define a novel RIP1/3-SIRT1/2-HAT1/4 complex. Mass spectrometry identified five acetylations in the kinase and death domain of RIP1. The novel characterized pan-SIRT inhibitor, MC2494, increases RIP1 acetylation at two additional sites in the death domain. Mutagenesis of the acetylated lysine decreases RIP1-dependent cell death, suggesting a role for acetylation of the RIP1 complex in cell death modulation. Accordingly, MC2494 displays tumor-selective potential in vitro, in leukemic blasts ex vivo, and in vivo in both xenograft and allograft cancer models. Mechanistically, MC2494 induces bona fide tumor-restricted acetylated RIP1/caspase-8-mediated apoptosis. Excitingly, MC2494 displays tumor-preventive activity by blocking 7,12-dimethylbenz(α)anthracene-induced mammary gland hyperproliferation in vivoConclusions: These preventive features might prove useful in patients who may benefit from a recurrence-preventive approach with low toxicity during follow-up phases and in cases of established cancer predisposition. Thus, targeting the newly identified RIP1 complex may represent an attractive novel paradigm in cancer treatment and prevention. Clin Cancer Res; 24(12); 2886-900. ©2018 AACR.

Successful Treatment of a Keratoacanthoma with Electrochemotherapy: A Case Report.

INTRODUCTION: Few studies have evaluated the efficacy of intralesional bleomycin injection combined with electroporation for the treatment of cutaneous tumors. However, the phenomenon that electroporation can enhance the cytotoxicity of bleomycin in vivo by 300-700 fold has been intensely investigated. CASE PRESENTATION: Keratoacanthoma in an 86-year-old patient was treated with intralesional bleomycin combined with electroporation. Treatment consisted of local application of shorty and intense electric pulses followed by local injection of bleomycin. Electroporation was always well tolerated by the patient, with no significant complaints, and the tumor had completely regressed by day 71 of the follow-up. CONCLUSION: The results suggest that intralesional bleomycin injection combined with electroporation could represent a valid alternative therapeutic approach for the treatment of keratoacanthomas.

Successful treatment of plantar warts with intralesional bleomycin and electroporation: pilot prospective study.

BACKGROUND: Numerous studies have been performed to evaluate the efficacy of intralesional bleomycin for the treatment of warts with inconsistent result. Nevertheless, it is well known that the cytotoxicity of bleomycin can be enhanced in vivo by 300 to 700-fold by electroporation. OBJECTIVE AND METHODS: In this article, we present an interventional, one-center, prospective case series, clinical trial of the effectiveness of intralesional bleomycin combined with electroporation for the treatment of plantar warts, in comparison to the use of intralesional bleomycin alone. RESULTS: The study's cohort included 12 men and 10 women, with a mean age of 53.8 years. A total of 22 warts were treated. In dividing the patients in two groups (complete remission against all the others) and analyzing the different outcomes in the two arms of patients, a statistical significant difference was found (p=0.0015), proving a greater efficacy of the treatment with bleomycin combined with ECT as opposed to bleomycin alone. Electroporation was always well tolerated by the patients with no discomfort. CONCLUSIONS: This study serves as a basis for the application of novel protocols in the treatment of different benign and locally malignant skin lesion by means of electroporation.

Surgery and electrochemotherapy treatment of incompletely excised mammary carcinoma in two male pet rats (Rattus norvegicus).

Two male rats (Rattus norvegicus; 18 and 24 months old), were referred for treatment of large masses located in the axillary area. Following total body radiography and hematological and serum biochemical analysis, the rats were anesthetized, and the masses were surgically removed. Both lesions were diagnosed as mammary carcinoma based on histopathological diagnosis. The tumor beds were treated with two sessions of electrochemotherapy (ECT), two weeks apart. ECT involved cisplatin administration in the tumor bed, followed by a series of eight biphasic electric pulses. The treatment was well tolerated, and the rats were disease-free after 10 and 14 months. Therefore, adjuvant ECT resulted in good local control of mammary carcinoma and can potentially be used for adjuvant treatment of pet rats with cutaneous and adnexal tumors.

Novel Instruments for the Implementation of Electrochemotherapy Protocols: From Bench Side to Veterinary Clinic.

Electrochemotherapy (ECT) is a medical strategy that allows an increased efficacy of chemotherapy agents after the application of permeabilizing electric pulses having appropriate characteristics (form, voltage, frequency). In the past 10 years, the clinical efficacy of this therapeutic approach in several spontaneous models of tumors in animals has been shown. Moreover, some of the molecular and cellular mechanisms responsible for this phenomenon have been elucidated. Our group has been deeply involved in the development of new ECT protocols for companion animals, implementing the use of the technique as first line treatment, and evaluating different chemotherapy agents in laboratory animals as well as pets. This article summarizes the most important advances in veterinary ECT, including the development of novel equipment, therapeutic protocols, and their translation to humans. J. Cell. Physiol. 232: 490-495, 2017. © 2016 Wiley Periodicals, Inc.

Histological and Immunohistochemical Characterization of a Case of Endometriosis in a Guinea Pig (Cavia tschudii).

Endometriosis is a chronic gynecological disease characterized by the ectopic proliferation of endometrial tissue outside of the uterine cavity. The pathogenesis of this disease is still obscure, and Sampson's theory of retrograde menstruation is still the most widely accepted explanation. Endometriosis in animals has been so far described not only in baboons and a rhesus macaque but also in dogs and horses that are nonmenstruating animals. In this article, we report the histological and immunohistochemical characterization of the first case of ovarian cystic endometriosis and adenomyosis in a guinea pig. The case presented supports the hypothesis that endometriosis is a disease not at all related to the phenomenon of retrograde menstruation but is a consequence of some alterations in the morphogenesis of the female genital system and therefore it could be found in any mammal. We suggest considering endometriosis among the other pathological phenotypes in animals displaying ovarian and uterine alterations and having a history of difficulties in conceiving.

Dietary Protective Effects Against Hepatocellular Carcinoma Development in Mdr2-/- Knockout Mice.

BACKGROUND/AIM: The Mdr2(-/-) mouse develops early chronic cholestatic hepatitis and hepatocellularcarcinoma (HCC) when adult. We tested the effects of a restricted-calorie diet on HCC development in Mdr2(-/-) mice. MATERIALS AND METHODS: Mdr2(-/-) mice (n=40, divided into two groups of 20 mice each) were randomized to receive ad libitum diet or restricted-calorie diet. Two mice from each group were sacrificed at 3 and 6 months, and liver tissue samples were removed for analysis. The remaining mice were fed their respective diets until the age of 30 months, at which time they were euthanized and livers were collected for analysis. RESULTS: The restricted-calorie diet had partial chemopreventive effect on the development of HCC in Mdr2(-/-) mice. Moreover, mice with ad libitum diet had a median survival of 361 days, while the restricted-calorie group had a median survival of 500 days (p=0.0001). CONCLUSION: A restricted diet might reduce the chance of developing HCC in patients at risk and could increase the protective action of anti-inflammatory agents.

Surgery and electrochemotherapy for the treatment of cutaneous squamous cell carcinoma in a yellow-bellied slider (Trachemys scripta scripta).

CASE DESCRIPTION: A 5-year-old female yellow-bellied slider (Trachemys scripta scripta) was referred for evaluation of a 2-month nonhealing ulcerated mass on the dorsal aspect of the neck. CLINICAL FINDINGS: The turtle was quiet, alert, and responsive, with a 2 × 1.5-cm ulcerated lesion on the neck. Signs of discomfort were observed during manipulation of the neck; no other abnormalities were detected during physical evaluation. TREATMENT AND OUTCOME: Following total body radiography and hematologic and serum biochemical analysis, the turtle was anesthetized and the mass was surgically removed. The excised tissue was submitted for histologic evaluation. A histopathologic diagnosis of squamous cell carcinoma (SCC) was made. Further surgical revision was not an option because of the extensive nature of the lesion; therefore, the tumor bed was treated with electrochemotherapy (ECT). Two sessions of ECT were performed with a 2-week interval between treatments. Electrochemotherapy involved intratumoral administration of bleomycin followed by trains of biphasic electric pulses. The treatment was well tolerated, and the turtle was disease free after 12 months. CLINICAL RELEVANCE: ECT resulted in good local control of SCC and should be considered as a possible postsurgical adjuvant treatment in reptiles with cutaneous tumors.

High dose lansoprazole combined with metronomic chemotherapy: a phase I/II study in companion animals with spontaneously occurring tumors.

BACKGROUND: The treatment of human cancer has been seriously hampered for decades by resistance to chemotherapeutic drugs. A very efficient mechanism of tumor resistance to drugs is the proton pumps-mediated acidification of tumor microenvironment. Metronomic chemotherapy has shown efficacy in adjuvant fashion as well as in the treatment of pets with advanced disease. Moreover, we have shown in veterinary clinical settings that pre-treatment with proton-pumps inhibitors (PPI) increases tumor responsiveness to chemotherapeutics. In this study pet with spontaneously occurring cancer have been recruited to be treated by a combination of metronomic chemotherapy and high dose PPIs and their responses have been matched to those of a historical control of ten patients treated with metronomic chemotherapy alone. METHODS: Single arm, non randomized phase II open study, with historical control group, evaluating safety and efficacy of the combination of metronomic chemotherapy and alkalization. Twenty-four companion animals (22 dogs and 2 cats) were treated adding to their metronomic chemotherapy protocol the pump inhibitor lansoprazole at high dose, and a water alkalizer. Their responses have been evaluated by clinical and instrumental evaluation and matched to those of the control group. RESULTS: The protocol was overall well tolerated, with only two dogs experiencing side effects due to gastric hypochlorhydria consisting with vomiting and or diarrhea. In terms of overall response, in the alkalized cohort, 18 out of 24 had partial or complete responses (75%), two patients had a stable disease and the remaining patients experienced no response or progressive disease. On the other hand, only one patient in the control group experienced a complete response (10%) and three other experienced short lived responses. Median time to terminal event was 34 weeks for the experimental group versus 2 weeks in the controls (p= 0.042). CONCLUSIONS: Patient alkalization has shown to be well tolerated and to increase tumor response to metronomic chemotherapy as well the quality of life in pets with advanced cancer. Further studies are warranted to assess the efficacy of this strategy in patients with advanced cancers in companion animals as well as in humans.

Electrochemotherapy in veterinary oncology: from rescue to first line therapy.

Electroporation is a delivery technique that is gaining popularity among the veterinary community due to its low cost, ease of application, and flexibility. It combines the administration of pharmaceutical compounds such as chemotherapy agents, antisense, and plasmids to the application of permeabilizing pulses. This chapter reviews the veterinary results obtained through the delivery of anticancer drugs (electrochemotherapy) and genes (electro-gene therapy).