Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.

Endothelial dysfunction due to the inhibition of the synthesis of nitric oxide: Proposal and characterization of an in vitro cellular model

The vascular endothelium plays a pivotal role in the maintenance of vascular homeostasis, mediated by vasoactive molecules produced by endothelial cells. The balance between vasoconstrictor and vasodilator biomolecules is what guarantees this equilibrium. Therefore, an increase in the bioavailability of vasoconstrictors along with a reduction in vasodilators may indicate a condition known as endothelial dysfunction. Endothelial dysfunction is marked by an inflammatory process and reduced activity of vasoprotective enzymes, being characterized by some factors like the reduction of the bioavailability of nitric oxide (NO) and increase in the production of reactive oxygen species (ROS), pro-inflammatory and vasoconstrictor molecules. This condition is a predictive marker of several cardiovascular diseases (e.g., atherosclerosis, hypertension, and diabetes). Research is affected by the scarcity of suitable in vitro models that simulate endothelial dysfunction. The goal of this study was to induce an in vitro condition to mimic endothelial dysfunction by inhibiting NO synthesis in cells. Thymus-derived endothelial cells (tEnd.1) were treated with different concentrations of L-NAME (from 1 to 1,000 μM) for different times (12, 24, 48, 72, 96, and 120 h without and with retreatment every 24 h). Cell viability, nitrite concentration, p22phox, NOX2, NOX4, IL-6, and ACE genes expression and lipid peroxidation were evaluated. The results indicate that the treatment with 100 μM L-NAME for 72 h without retreatment reduced NO concentration and NOX4 gene expression while increasing ACE expression, thus mimicking reduced vascular protection and possibly increased vasoconstriction. On the other hand, treatment with 100 μM L-NAME for 96 h with retreatment reduced the concentration of NO and the expression of the p22phox gene while increasing the expression of the IL-6 and ACE genes, mimicking the increase in inflammation and vasoconstriction parameters. Based on these results, we thus propose that both 100 μM L-NAME for 72 h without retreatment and 100 μM L-NAME for 96 h with retreatment may be used as models for in vitro endothelial dysfunction according to the purpose of the study to be conducted.

PP082. Ophthalmic artery doppler for identification of severe preeclampsia in pregnancies complicated by hypertension

INTRODUCTION

Hypertension is the most common disorder that occurs during pregnancy and one of the main causes of maternal mortality worldwide. Among the hypertensive disorders that affect pregnancy, preeclampsia (PE) is the major cause of maternal mortality, maternal morbidity, perinatal death, prematurity and intrauterine growth restriction. The acute cerebral complications in PE account for at least 75% of maternal death. Central nervous system hemodynamic modifications in PE are a controversial issue. Neurological involvement in PE-eclampsia syndrome fulfills the criteria of posterior reversible encephalopathy syndrome (PRES). The pathophysiology of PRES is still under investigation. Assessment of cerebral circulation is challenging. Noninvasive techniques, especially transcranial Doppler sonography, are becoming more widely used to evaluate cerebral flow. Ophthalmic artery Doppler is a noninvasive examination used to study central vascular flow that has been shown to be a promising method in the evaluation of pregnant women with hypertension.

OBJECTIVES

The aim of this study was to compare the ophthalmic artery Doppler indices observed in singleton pregnant women complicated by hypertension (study group) and to correlate the indices observed in hypertensive pregnant women with those observed in normal pregnant women (control group).

METHODS

Ophthalmic artery Doppler indices of 30 mild and 30 severe pre-eclamptic women and 30 pregnant women with chronic hypertension (CH) at 20-40weeks of gestational age (GA) were compared. The control group consisted of 289 healthy pregnant women. Resistance index (RI), pulsatility index (PI), and peak ratio (PR) were determined in the right eye. The mean and SD were calculated for each group. Analysis of variance (ANOVA) was used to compare Doppler indexes means between groups. As significant differences were determined by ANOVA analysis, each group was compared by the Tukey method. Receiver operating characteristics (ROC) curves were used to determine the predictive power of ophthalmic artery Doppler indexes for the identification of severe pre-eclamptic women. P<0.05 was considered statistically significant.

RESULTS

Significant differences were found between the values obtained for RI, PI, and PR in severe PE women compared to the other groups (study and control). The mean and SD for IR, IP and PR in mild PE, severe PE and CH groups were respectively 0.73 (±0.06), 1.63 (±0.35) and 0.65 (±0.10); 0.63 (±0.09), 1.13 (±0.31) and 0.89 (±0.12); 0.73 (±0.07), 1.66 (±0.49) and 0.66 (±0.14). The mean and SD for IR, IP and PR in normotensive pregnant women were 0.75 (±0.05), 1.88 (±0.43), 0.52 (±0.10). The optimal cut-off values for IR, IP and PR for the identification of severe pre-eclamptic women determined by roc curves was 0.657, 1.318, 0.784 (sensitivity and specificity were 0.633 and 0.919, 0.733 and 0.888, 0.833 and 0.974, respectively). The area under the ROC curve for IR was 0.787(95% CI: 0.68-0.89), for IP was 0.797 (95% CI: 0.69-0.90) and for PR was 0.886 (95% CI: 0.80-0.96).

CONCLUSION

Ophthalmic Doppler is a useful method in the identification of severe PE. PR was best ophthalmic Doppler index at discriminating between severe PE and pregnant women with mild PE or chronic hypertension as determined by roc curve.