MicroRNA Profiling of the Effect of the Heptapeptide Angiotensin-(1-7) in A549 Lung Tumor Cells Reveals a Role for miRNA149-3p in Cellular Migration Processes

The functional activity of the miR-1914-5p in lipid metabolism of the hepatocarcinoma cell line HepG2: a potential molecular tool for controlling hepatic cellular migration

Hepatocellular carcinoma is one of the most common types of cancer in the world with high mortality rate and new therapies that control of fatty acid metabolism may limit the proliferation of cancer cells. In the last two decades, the non-coding RNAs have been considered as promising molecular tools to treat diseases, because they are able to modulate gene expression and the metabolic routes; however, deep investigation of their mechanistic behavior in pathologies must be performed. Thus, our aim was to evaluate the modulatory effect of the miR-1914-5p in controlling lipid metabolism in HepG2, a widely used human hepatocarcinoma cell line. The molecular and cellular analyses demonstrated that the functional inhibition of the investigated microRNA completely changed the cellular metabolism and behavior, compared to control groups. The in vitro inhibition of the miR-1914-5p increased the energy expenditure pointed in different analyses, decreasing cell doubling time and migration rate verified in wound healing and in the classical transwell chambers invasion assays, which makes the miR-1914-5p a candidate for further translational and preclinical studies to validate its function in controlling metastasis in liver cancer or even treat those diseases.

Renin-angiotensin system and cancer: epidemiology, cell signaling, genetics and epigenetics

Day by day, the health and economical burden of cancer increases globally. Indeed it can be considered that there is ''cancer pandemic''. Blocking the renin-angiotensin system (RAS) by angiotensin-converting enzyme (ACE) inhibitors (ACEI) or angiotensin-receptor blockers (ARB) are widely used measures to treat hypertension and heart failure. It has been recently suggested the activation and blocking of RAS has been associated with various types of cancer in epidemiological and experimental studies. Various studies have shown that RAS blockage is protective in some cancers. However, although fewer, contradictory data also showed that RAS blockage is either not related or adversely related to cancer. Although the reasons for these findings are not exactly known, different types of receptors and effectors in RAS may account for these findings. In the current review, we summarize the different RAS receptors and cancer development with regard to epidemiology, and pathogenesis including cell signaling pathways, apoptosis, genetic and epigenetic factors.

Cellular and molecular effects of silymarin on the transdifferentiation processes of LX-2 cells and its connection with lipid metabolism

Fibrosis process in the liver is a clinical condition established in response to chronic lesions and may be reversible in many situations. In this process, hepatic stellate cells (HSCs) activate and produce extracellular matrix compounds. During fibrosis, the lipid metabolism is also altered and contributes to the transdifferentiation of the HSCs. Thus, controlling lipid metabolism in HSCs is suggested as a method to control or reverse the fibrotic condition. In the search for therapies that modulate lipid metabolism and treat liver diseases, silymarin has been identified as a relevant natural compound to treat liver pathologies. The present study aimed to evaluate the cellular and molecular effects of silymarin in the transdifferentiation process of HSCs (LX-2) from activated phenotype to a more quiesced-like cells , also focusing on understanding the modulatory effects of silymarin on lipid metabolism of HSCs. In our analyses, 100 µM of silymarin reduced the synthesis of actin filaments in activated cells, the synthesis of the protein level of α-SMA, and other pro-fibrotic factors such as CTGF and PFGF. The concentration of 150 µM silymarin did not reverse the activation aspects of LX-2 cells. However, both evaluated concentrations of the natural compound protected the cells from the negative effects of dimethyl sulfoxide (DMSO). Furthermore, we evaluated lipid-related molecules correlated to the transdifferentiation process of LX-2, and 100 µM of silymarin demonstrated to control molecules associated with lipid metabolism such as FASN, MLYCD, ACSL4, CPTs, among others. In contrast, cellular incubation with 150 µM of silymarin increased the synthesis of long-chain fatty acids and triglycerides, regarding the higher presence of DMSO (v/v) in the solvent. In conclusion, silymarin acts as a hepatoprotective agent and modulates the pro-fibrogenic stimuli of LX-2 cells, whose effects depend on stress levels in the cellular environment.

Association between the miRNA-149 rs2292832 T>C polymorphism and Kawasaki disease susceptibility in a southern Chinese population

Background

Kawasaki disease (KD), which is characterized by vasculitis, is prone to occur in patients under 5 years of age, has an ambiguous etiology, and displays coronary artery lesions as the chief complication. Previous studies have linked miRNA‐149 to cancers, and rs2292832 T>C is related to allergic diseases and inflammatory bowel disease, which both show immune system disorders and coronary artery disease. Therefore, we performed a study concentrating on the association between the miRNA‐149 rs2292832 T>C polymorphism and KD susceptibility.

Methods

The subjects enrolled were 532 children with KD and 623 controls. We used TaqMan real‐time PCR to obtain the genotypes of the rs2292832 T>C polymorphism.

Results

Ultimately, no significant association was found between the miRNA‐149 rs2292832 T>C polymorphism and KD susceptibility, even in stratification analysis.

Conclusion

Our results indicated that in southern Chinese patients, the miRNA‐149 rs2292832 T>C polymorphism did not affect KD susceptibility, which needs to be further confirmed.

The modulatory effect of triclosan on the reversion of the activated phenotype of LX-2 hepatic stellate cells

Hepatic diseases leading to fibrosis affect millions of individuals worldwide and are a major public health challenge. Although, there have been many advances in understanding hepatic fibrogenesis, an effective therapy remains elusive. Studies focus primarily on activation of the hepatic stellate cells (HSCs), the principal fibrogenic cells in the liver; however, fewer numbers of studies have examined molecular mechanisms that deactivate HSC, controlling the profibrogenic phenotype. In the present study, we evaluated cellular and molecular actions of the chemical triclosan (TCS) in reverting activated HSCs to a quiesced phenotype. We demonstrated that the inhibition of the enzyme fatty acid synthase by TCS in activated HSCs promotes survival of the cells and triggers cellular and molecular changes that promote cellular phenotypic reversion, offering potentially new therapeutic directions.

EXPRESSION OF THE RENIN-ANGIOTENSIN SYSTEM COMPONENTS IN ONCOLOGIC DISEASES

The literature devoted to changes in the expression of the renin-angiotensin system (RAS) proteins of cancer cells was analyzed. The dynamics of RAS protein expression in malignant tumors and the possible role of epigenetic mechanisms in these processes are briefly reviewed. Through research of the epigenetic mechanisms in cancer, principally new techniques for their correction based on the use of selective regulatory systems of covalent modification of histone proteins (for example, deacetylase inhibitor) and microRNA synthesis technologies have been developed. Literature data show promising pharmacological correction of epigenetic modification of chromatin in the treatment of cancer.

The Role of Angiotensin–(1-7) in Cancer

The rationale to investigate the role of angiotensin-(1-7) [Ang-(1-7)] in cancer relies on the fact that the heptapeptide inhibits the growth of several cell lines. The first studies showed that Ang-(1-7) accelerated hematopoietic recovery in the peripheral blood and bone marrow after chemotherapy and inhibits lung cancer cell growth through the activation of Mas receptor. In this chapter, we summarize studies on the role of Ang-(1-7) in different types of cancer, especially lung, breast, prostate, hepatocellular cancers and in gliobalstoma multiforme (GBM). The antitumor effect of Ang-(1-7) was due to reduction of angiogenesis, cancer-associated fibrosis, osteoclastogenesis, tumor-induced inflammation, and metastasis as well as inhibition of cancer cell growth and proliferation. In clinical trials, Ang-(1-7) was well tolerated with limited toxic or quality-of-life side effects and showed clinical benefit in cancer patients with solid tumors. Further clinical trials are needed to confirm safety, to determine doses and clinical indications.

Altered global microRNA expression in hepatic stellate cells LX-2 by angiotensin-(1-7) and miRNA-1914-5p identification as regulator of pro-fibrogenic elements and lipid metabolism

The development of new therapeutic strategies to control or reverse hepatic fibrosis requires thorough knowledge about its molecular and cellular basis. It is known that the heptapeptide angiotensin-(1-7) [ang-(1-7)] can reduce hepatic fibrosis and steatosis in vivo; therefore, it is important to uncover the mechanisms regulating its activity and cellular model of investigation. Ang-(1-7) is a peptide of the renin-angiotensin system (RAS), and here we investigated its modulatory effect on the expression pattern of microRNAs (miRNAs) in hepatic stellate cells (HSCs) LX-2, which transdifferentiate into fibrogenic and proliferative cells. We compared the miRNA profiles between quiesced, activated and ang-(1-7)-treated activated HSCs to identify miRNAs that may regulate their transdifferentiation. Thirteen miRNAs were pointed, and cellular and molecular analyses identified miRNA-1914-5p as a molecule that contributes to the effects of ang-(1-7) on lipid metabolism and on the pro-fibrotic environment control. In our cellular model, we also analyzed the regulators of fatty acid metabolism. Specifically, miRNA-1914-5p regulates the expression of malonyl-CoA decarboxylase (MLYCD) and phosphatidic acid phosphohydrolase (PAP or Lipin-1). Additionally, Lipin-1 was closely correlated with mRNA expression of peroxisome proliferator-activated receptors (PPAR)-α and -γ, which also contribute to lipid homeostasis and to the reduction of TGF-β1 expression. These findings provide a novel link between RAS and lipid metabolism in controlling HSCs activation.

The ACE2/Angiotensin-(1-7)/Mas Receptor Axis: Pleiotropic Roles in Cancer

Cancer remains one of the most common causes of death and disability and represents a major economic burden in industrialized nations. The renin-angiotensin system (RAS) has been well-recognized as one of the most important regulators of both normal and pathological physiological processes in the brain, kidney, heart, and blood vessels. The activation of the angiotensin-converting enzyme 2/angiotensin-(1–7)/mitochondrial assembly receptor [ACE2/Ang-(1–7)/MasR] axis, which is one component of the RAS, has recently been identified as a critical component of pulmonary systems, gastric mucosa, and cancer. However, the ability of the ACE2/Ang-(1–7)/MasR axis to suppress or promote cancer has not been fully elucidated. In this review, we focus on recent experimental and clinical studies investigating the basic properties, roles, and mechanisms of ACE2, Ang-(1–7), and the MasR, as well as the axis pathway, to provide insights into possible therapeutic strategies for treating cancer that target the ACE2/Ang-(1–7)/MasR axis.