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.

Evaluation of angiogenesis, inflammation, and healing on irradiated skin graft with low-level laser therapy in rats (Rattus norvegicus albinus wistar)

The reconstructive techniques have been widely used in Veterinary Medicine. The post-operative adjuvants therapies like the low-level laser therapy (LLLT) are used to decrease inherent complications to reconstructive surgeries. This article purposed to define the LLLT effects on the healing, inflammation, and vascularization of the skin grafts in applicable time intervals to veterinary surgical routine. Forty rats (Rattus norvegicus albinus wistar) were used and each one was submitted to autogenous cutaneous mesh grafting in the interescapular region. The rats were randomly distributed in five groups (G1, G2, G3, G4, and G5) in accordance with the 6 J/cm² or 10 J/cm² dose every 3 or 5 days. These treatments were applied on the skin graft for 15 days. The histochemical evaluation with Picrosirius showed greater expression of collagen type 1 - red in grafts of G5 (p < 0.05), while in G1 did not; the expression of collagen type III - green was not induced by LLLT. The histochemical evaluation with hematoxylin-eosin showed greater numbers of fibroblasts in grafts of G4 (p < 0.05) and less hemorrhage in grafts of G5 (p < 0.05). There was modulation of the inflammatory response in irradiated skin grafts. It is concluded the exhibition of the skin grafts to 6 J/cm² or 10 J/cm² dose every 5 days improved the healing and the modulation of the local inflammation.

Mitochondrial genetic diversity, selection and recombination in a canine transmissible cancer

Canine transmissible venereal tumour (CTVT) is a clonally transmissible cancer that originated approximately 11,000 years ago and affects dogs worldwide. Despite the clonal origin of the CTVT nuclear genome, CTVT mitochondrial genomes (mtDNAs) have been acquired by periodic capture from transient hosts. We sequenced 449 complete mtDNAs from a global population of CTVTs, and show that mtDNA horizontal transfer has occurred at least five times, delineating five tumour clades whose distributions track two millennia of dog global migration. Negative selection has operated to prevent accumulation of deleterious mutations in captured mtDNA, and recombination has caused occasional mtDNA re-assortment. These findings implicate functional mtDNA as a driver of CTVT global metastatic spread, further highlighting the important role of mtDNA in cancer evolution.

DOI:http://dx.doi.org/10.7554/eLife.14552.001

A unique cancer called canine transmissible venereal tumour (CTVT) causes ugly tumours to form on the genitals of dogs. Unlike most other cancers, CTVT is contagious: the cancer cells can be directly transferred from one dog to another when they mate. The disease originated from the cancer cells of one individual dog that lived approximately 11,000 years ago. CTVT now affects dogs all over the world, which makes it the oldest and most widespread cancer known in nature.

Like healthy cells, cancer cells contain compartments known as mitochondria that produce the chemical energy needed to power vital processes. Inside the mitochondria, there is some DNA that encodes the proteins that mitochondria need to perform this role. Changes (or mutations) to this mitochondrial DNA (mtDNA) may stop the mitochondria from working properly. CTVT cells have previously been found to occasionally capture mtDNA from normal dog cells, which suggests that replenishing their mtDNA may help promote CTVT cell growth. Furthermore, these captured mtDNAs act as genetic "flags" that can help trace the spread of the disease.

Here, Strakova, Ní Leathlobhair et al. analysed the mtDNA in CTVT tumours collected from over 400 dogs in 39 countries. The analysis shows that CTVT cells have captured mtDNA from normal dog cells on at least five occasions. Over the last 2,000 years, the disease appears to have spread rapidly around the world, perhaps transported by dogs travelling on ships along historic trade routes. CTVT may have only reached the Americas within the last 500 years, possibly carried there by dogs brought by Europeans. Likewise, CTVT probably only came to Australia after European contact.

The experiments also revealed that the most damaging types of mutations were absent from the mtDNA of CTVT, which suggests that fully functioning mitochondria play an important role in CTVT. Unexpectedly, Strakova, Ní Leathlobhair et al. found evidence that certain sections of mtDNA in some CTVT cells have been exchanged, or shuffled, with the mtDNA captured from normal dog cells. This type of “recombination” is not usually thought to occur in mtDNA, and has not previously been detected in cancer. Future studies will determine if this process is widespread in other types of cancer, including in humans.

DOI:http://dx.doi.org/10.7554/eLife.14552.002

Method to obtain platelet-rich plasma from rabbits (Oryctolagus cuniculus )

Abstract: Platelet-rich plasma (PRP) is a product easy and inxpesnsive, and stands out to for its growth factors in tissue repair. To obtain PRP, centrifugation of whole blood is made with specific time and gravitational forces. Thus, the present work aimed to study a method of double centrifugation to obtain PRP in order to evaluate the effective increase of platelet concentration in the final product, the preparation of PRP gel, and to optimize preparation time of the final sample. Fifteen female White New Zealand rabbits underwent blood sampling for the preparation of PRP. Samples were separated in two sterile tubes containing sodium citrate. Tubes were submitted to the double centrifugation protocol, with lid closed and 1600 revolutions per minute (rpm) for 10 minutes, resulting in the separation of red blood cells, plasma with platelets and leucocytes. After were opened and plasma was pipetted and transferred into another sterile tube. Plasma was centrifuged again at 2000rpm for 10 minutes; as a result it was split into two parts: on the top, consisting of platelet-poor plasma (PPP) and at the bottom of the platelet button. Part of the PPP was discarded so that only 1ml remained in the tube along with the platelet button. This material was gently agitated to promote platelets resuspension and activated when added 0.3ml of calcium gluconate, resulting in PRP gel. Double centrifugation protocol was able to make platelet concentration 3 times higher in relation to the initial blood sample. The volume of calcium gluconate used for platelet activation was 0.3ml, and was sufficient to coagulate the sample. Coagulation time ranged from 8 to 20 minutes, with an average of 17.6 minutes. Therefore, time of blood centrifugation until to obtain PRP gel took only 40 minutes. It was concluded that PRP was successfully obtained by double centrifugation protocol, which is able to increase the platelet concentration in the sample compared with whole blood, allowing its use in surgical procedures. Furthermore, the preparation time is appropriate to obtain PRP in just 40 minutes, and calcium gluconate is able to promote the activation of platelets.

Paraneoplastic neutrophilic leukocytosis syndrome in a cat with recurrent mammary carcinoma

Case summary

A spayed 12-year-old female domestic shorthair cat presented with nodular lesions on the ventral-right thoracic wall after complete mastectomy 4 months previously. The prior diagnosis was tubulopapillary mammary carcinoma with axillary lymph node metastasis, and a recurrence was confirmed. A gradual and sequential increase in the total number of leukocytes with severe neutrophilia (95.632/µl) developed over the course of the illness, along with an increase in the size of the recurrent mass. The severe leukocytosis did not show any response to antibiotic therapy, and no evidence of infection was observed. Bone marrow cytology confirmed hypercellularity in the myeloid cell lineage. Based on these findings, paraneoplastic neutrophilic leukocytosis syndrome was suspected. An incisional biopsy of the recurrent mass was consistent with recurrent tubulopapillary mammary carcinoma. Malignant epithelial cells stained positive upon immunohistochemistry for granulocyte–macrophage colony-stimulating factor, cytokeratin and vimentin. After the final diagnosis of paraneoplastic neutrophilic leukocytosis syndrome, the cat was euthanized at the owner’s request.

Relevance and novel information

This is a novel case of paraneoplastic leukocytosis syndrome associated with mammary carcinoma in a cat. Although there are some reports describing paraneoplastic leukocytosis in cats, the relationship between this syndrome and feline mammary tumors has not been described.

Aspecto radiológico e macroscópico de matriz óssea mineralizada heteróloga fragmentada e polimetilmetacrilato autoclavados em falha óssea de tíbia de coelho

Foi realizada falha segmentar com 6mm de diâmetro na região metafisária medial de tíbias de 12 coelhos, onde foi implantado uma associação de micro e macrofragmentos de matriz óssea cortical heteróloga fragmentada conservada em glicerina (98%) e polimetilmetacrilato autoclavados, para a sua reconstrução, e avaliados radiológica e macroscopicamente aos 30, 60, 90 e 120 dias. Houve adesão, em relação ao tempo, dos micro e macrocompósitos ao leito receptor, em 100% dos casos, mostrando ser biologicamente biocompatível, pois promoveram a reparação de falhas ósseas, sem sinais de infecção, migração e/ou rejeição, podendo, dessa forma, ser mais uma opção como substituto para preencher grandes defeitos ósseos.

Abstract 1553: Down-expression of ATM gene and protein associated with canine breast tumors

Background: Ataxia telangiectasia mutated (ATM) gene encodes a protein associated with DNA damage repair that plays an important role in the maintenance of genome integrity. ATM transcript and protein down-regulation have been reported in sporadic breast carcinomas and the absence of ATM protein expression was also significantly associated with distant metastasis in women, but the mechanisms involved in the ATM deregulation are not well established.

Aim: Due to the fact that mammary tumor biological behavior is similar between canine and humans, we evaluate ATM gene and protein expression in canine breast cancer and compared with normal mammary gland from dogs.

Patients and methods: Fresh samples of non-metastatic (n=23) and metastatic mammary carcinomas (n=11) and normal breasts (n=10) were evaluated for ATM gene expression by RT-qPCR and from the same animals, another sample of tumor was collected, formalin-fixed and paraffin-embedded to assess ATM protein expression by immunohistochemistry. Evaluation of ATM protein expression was performed by the distribution of positively-immunostained tumor cells in scores: 1 (&lt;25% cells positive), 2 (26% to 50% cells positive) and 3 (&gt;51% cells positive).

Results: Down expression of ATM was detected in tumors samples (non-metastatic and metastatic mammary carcinomas) when compared to normal breast samples (P= 0,0414). Additionally, scores 1 and 2 of ATM protein expression were exclusively observed in metastatic tumors presenting score 1: 18% (2 out of 11), score 2: 55% (6 out to 11) and non metastatic tumors presenting the same score 1 and 2: 17% (4 out to 23) while all normal breast tissues showed score 3 (P=0,0087).

Conclusions: Down expression of ATM transcript was confirmed by ATM protein expression. Low levels of ATM suggest an involvement of DNA damage repair transcript and protein in tumorigenesis process of canine mammary tumors, as in women, corroborating for the use of dogs as a natural comparative model to study mammary gland tumors in humans.

Citation Format: Talita Mariana Morata Raposo, Renata C. Bueno, Márcio de Carvalho, Carlos E. Fonseca-Alves, Mirela Tinucci-Costa, Andrigo B. De Nardi, Silvia R. Rogatto, Renée Laufer-Amorim. Down-expression of ATM gene and protein associated with canine breast tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1553. doi:10.1158/1538-7445.AM2013-1553