Over-expression of PTEN on proliferation and apoptosis in canine mammary tumors cells

Canine Mammary Cancer: State of the Art and Future Perspectives

Mammary cancer is the most frequently diagnosed neoplasia in women and non-spayed female dogs and is one of the leading causes of death in both species. Canines develop spontaneous mammary tumors that share a significant number of biological, clinical, pathological and molecular characteristics with human breast cancers. This review provides a detailed description of the histological, molecular and clinical aspects of mammary cancer in canines; it discusses risk factors and currently available diagnostic and treatment options, as well as remaining challenges and unanswered questions. The incidence of mammary tumors is highly variable and is impacted by biological, pathological, cultural and socioeconomic factors, including hormonal status, breed, advanced age, obesity and diet. Diagnosis is mainly based on histopathology, although several efforts have been made to establish a molecular classification of canine mammary tumors to widen the spectrum of treatment options, which today rely heavily on surgical removal of tumors. Lastly, standardization of clinical study protocols, development of canine-specific biological tools, establishment of adequate dog-specific disease biomarkers and identification of targets for the development of new therapies that could improve survival and have less adverse effects than chemotherapy are among the remaining challenges.

Anti-cancer potentials of Gynura procumbens leaves extract against two canine mammary cancer cell lines

BACKGROUND

The anti-cancer effects of Gynura procumbens leaves extract (GPE) have been reported in various human cancers. However, the anti-cancer effects and molecular mechanisms of this extract on canine mammary cancer (CMC) have not yet been elucidated.

OBJECTIVES

The main goal of this study was to investigate the anti-cancer properties of GPE against two CMC cell lines (CHMp-13a and CHMp-5b).

METHODS

The GP leaves were extracted with 80% ethanol. Anti-cancer potentials of GPE on CHMp-13a and CHMp-5b cancer cell lines using dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium bromide (MTT), wound healing, transwell migration, and caspase 3/7 activity assays were evaluated. The mRNA expression levels of two oncogenes: epidermal growth factor receptor (EGFR) and twist family bHLH transcription factor 1 (TWIST) and one tumour suppressor gene: phosphatase and tensin homolog (PTEN) in these cell lines were determined by quantitative real-time PCR (qRT-PCR). In addition, The EGFR and PTEN protein levels as well as protein kinase B (AKT) and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation levels expression were also evaluated by western blot analysis.

RESULTS

The results showed that GPE caused a significant concentration- and time-dependent reduction in cell proliferation of both CHMp-13a and CHMp-5b cells, detected by MTT assays. This extract also significantly suppressed cancer cell migration in both cell lines, tested by wound healing and transwell migration assays. Additionally, the increase in caspase 3/7 activity observed in both CMC cell treated with GPE suggests that GPE induced caspase 3/7 dependent apoptosis. Moreover, GPE significantly decreased EGFR mRNA and protein expression levels compared to control in both cell lines in a dose-dependent manner.

CONCLUSION

These findings emphasized that GPE has an in vitro anti-cancer activity against CMC by inhibiting EGFR signalling pathway. Thus, GPE may serve as an alternative therapy in CMC with high EGFR expression.