Emerging roles of regulatory T cells in tumour progression and metastasis.

The metastasis of cancer is a complex and life-threatening process that is only partially understood. Immune suppressive cells are recognized as important contributors to tumour progression and may also promote the development and growth of tumour metastases. Specifically, regulatory T cells (Tregs) have been found to promote primary tumour progression, and emerging pre-clinical data suggests that Tregs may promote metastasis and metastatic tumour growth. While the precise role that Tregs play in metastatic progression is understudied, recent findings have indicated that by suppressing innate and adaptive anti-tumour immunity, Tregs may shield tumour cells from immune detection, and thereby allow tumour cells to survive, proliferate and acquire characteristics that facilitate dissemination. This review will highlight our current understanding of Tregs in metastasis, including an overview of pre-clinical findings and discussion of clinical data regarding Tregs and therapeutic outcome. Evolving strategies to directly ablate Tregs or to inhibit their function will also be discussed. Improving our understanding of how Tregs may influence tumour metastasis may lead to novel treatments for metastatic cancer.

The potential role of pumpkin seeds oil on methotrexate-induced lung toxicity.

Many chemotherapeutic drugs cause adverse pulmonary reactions leading to severe pulmonary disease. Though methotrexate (MTX) is used for the treatment of cancer and other diseases, it is highly toxic with multiple adverse effects including pulmonary toxicity. Essential oils represent an open frontier for pharmaceutical sciences due to their wide range of pharmacological properties. Pumpkin seeds oil (PSO) was used to investigate its ability to alleviate methotrexate-induced lung toxicity in rats. Lung tissue from MTX-treated group revealed a decrease in malondialdehyde, glutathione, and nitric oxide accompanied by a marked inhibition in cholinesterase activity, and enhanced catalase activity, tumor necrosis factor-α, interleukin-6 and vascular endothelial growth factor levels. Analysis of PSO revealed that the oil was rich in hexadecanoic acid, decane methyl esters, squalene, polydecane, docosane, and other derivatives. Administration of PSO ameliorated the oxidant/antioxidant and proinflammatory changes induced by MTX in the lung tissue. Histological examinations confirmed the potency of PSO in reducing the histopathological alterations induced by MTX. Immunohistochemical analysis showed decreased nuclear factor-kappa B and caspase 3 expression after PSO. The present data indicated the protective efficiency of PSO against MTX-induced lung injury by decreasing oxidative damage, inflammation and apoptosis and could thus be recommended as an adjuvant therapy.

An evaluation of the clinical significance of FOXP3+ infiltrating cells in human breast cancer.

Studies in mice have shown that thymic-derived CD4+ CD25+ regulatory T cells (T reg; FOXP3(+) lymphocytes) inhibit an antitumour immune response. Additional studies have also reported that the T reg population increases in peripheral blood and tumour tissues from patients with cancer. However, the relationship between the T reg population and the patient prognosis remains controversial. Our aim was to determine the prognostic value of T reg cell density in breast cancer using immunohistochemical assessment of FOXP3, which has been shown to be the optimal marker for T regs. Tissue microarrays were used, and the density of FOXP3(+) cells was determined in a series of 1445 cases of well-characterised primary invasive breast carcinoma cases with long-term follow up. FOXP3(+) cell numbers were counted in tumour nests, in tumour-adjacent stroma, and in distant stroma. The total number of FOXP3(+) cells significantly correlated with higher tumour grade (r (s) = 0.37, P < 0.001) and ER negativity (Mann-Whitney U test, P < 0.001). In addition, FOXP3 infiltration positively correlated with HER2 expression and basal phenotype subclass. On univariate analysis, FOXP3(+) cells were associated with a worse prognosis (P = 0.012, log rank = 6.36). This association was found for intratumoural FOXP3(+) and for tumour-adjacent stromal FOXP3(+)-cells (tumour-cell associated FOXP3, P = 0.001 and log rank 10.35). However, the number of FOXP3(+) cells was not found to be an independent prognostic factor in multivariate analysis. We therefore conclude that FOXP3(+) infiltrating cells do not have a dominant role in breast cancer prognosis and suggest that other inflammatory cell subsets may be more critical variables.

Potential role of N-acetylcysteine on chlorpyrifos-induced neurotoxicity in rats.

Chlorpyrifos (CPF) is a widely used organophosphate insecticide with several harmful effects. N-acetylcysteine (NAC) represents an ideal antixenobiotic; it can directly enter endogenous biochemical processes and is used as adjunctive treatment for psychiatric disorders. We aimed to evaluate the neuroprotective effect of NAC as an antioxidant drug against CPF-induced neurotoxicity in adult male albino rat brains. Twenty-eight male Wister rats were allocated into four groups (n = 7) and were administered the following for 28 days: group I (control group), physiological saline (0.9% NaCl); group II (CPF group), 10 mg/kg body weight (BW) CPF; group III (NAC group), 100 mg/kg BW NAC; and group VI (CPF+NAC group), NAC 1 h before CPF. CPF intoxication resulted in acetylcholinesterase inhibition, reduced glutathione content, and elevated levels of malondialdehyde and nitric oxide, which are oxidative stress biomarkers. CPF also depleted the activity of antioxidant enzymes, superoxide dismutase and catalase, and levels of inflammatory mediators, tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß. Levels of vascular endothelial growth factor, Bax, and the proapoptotic caspases-3 also increased, while brain-derived neurotrophic factor level decreased. Additionally, CPF significantly diminished Bcl-2 (an antiapoptotic protein) in rat brain cortical tissue. NAC treatment was found to protect brain tissue by reversing the CPF-induced neurotoxicity. Our results show the antioxidant, antiinflammatory, and antiapoptotic effects of NAC on CPF-induced neurotoxicity in rat brain tissue.

Ziziphus spina-christi fruit extract suppresses oxidative stress and p38 MAPK expression in ulcerative colitis in rats via induction of Nrf2 and HO-1 expression.

In this study, we aimed to evaluate the anti-inflammatory and protective effects of Ziziphus spina-christi fruit extract (ZFE) against acetic acid (AcOH)-induced colitis in rats. Before a single AcOH instillation, ZFE (100, 200, and 400 mg/kg/day) was administered for 5 days by oral gavage. Pretreatment with ZFE at different doses suppressed the spread of inflammation and inhibited mucosal damage; in addition, it reduced ulcer size and mitigated colitis markers. Administration of ZFE (400 mg/kg) resulted in a greater reduction of inflammatory colonic injury than that after reference drug, mesalazine (MLZ), administration. In addition, ZFE not only histopathologically ameliorated AcOH-induced colitis but also restored the balance between the oxidants and antioxidants. Furthermore, ZFE effectively modulated the mRNA expression of redox-sensitive transcription factors, such as nuclear factor (erythroid-derived 2)-like 2 and heme oxygenase-1, downregulated the expression of p38 mitogen-activated protein kinase, and upregulated that of vascular endothelial growth factor A and interleukin-1ß in AcOH-induced colitis in rats. In conclusion, our results suggested that ZFE could prevent the development of chronic experimental colitis in rats; therefore, it could be considered as an alternative and/or additive therapeutic approach for the management of inflammatory bowel disease.

Tumor-infiltrating CD8+ lymphocytes predict clinical outcome in breast cancer.

Breast carcinomas are often infiltrated by inflammatory cells, particularly macrophages and T lymphocytes, but the significance of these cells remains unclear. One possible role of these inflammatory cells is that they represent a cell-mediated immune response against the carcinoma. CD8(+) lymphocytes are a known crucial component of cell-mediated immunity. The purpose of this study was to explore the prognostic value of tumor-infiltrating CD8(+) cytotoxic lymphocytes in breast cancer. Tumor-infiltrating CD8(+) lymphocytes were assessed by immunohistochemical staining of tissue microarray cores from 1,334 unselected breast tumors from patients with long-term follow-up. The number of CD8(+) T cells was counted in tumor nests (intratumoral), in stroma adjacent to tumor cells, and in stroma distant to tumor cells, and their relationship with clinical outcome was determined. The total number of CD8(+) cells was positively correlated with tumor grade (r(s) = 0.20; P < .001) and inversely correlated with patient's age at diagnosis, estrogen receptor-alpha (ER-α), and progesterone receptor (PgR) expression (Mann-Whitney U test, P < .001). The total patient cohort was randomly divided into two separate training and validation sets before performing univariate survival analysis. Total number and distant stromal CD8(+) lymphocytes were associated with better patient survival (P = .041 and P < .001, respectively) in the training set. In multivariate analysis, total CD8(+) T-cell count was an independent prognostic factor in both training and validation sets. These results suggest that tumor-infiltrating CD8(+) T lymphocytes have antitumor activity as judged by their favorable effect on patients' survival and could potentially be exploited in the treatment of breast cancer.