Original Article: MicroRNA Dysregulation in the Gastric Carcinogenesis Cascade: Can We Anticipate Its Role in Individualized Care?

BACKGROUND: Gastric carcinogenesis progresses from normal mucosa, atrophic/metaplastic gastritis, and dysplasia to adenocarcinoma. MicroRNAs (miRNAs) regulate DNA expression and have been implicated; however, their role is not fully established. AIMS: The aim of this study was to characterize plasma and tissue expression of several miRNAs in gastric carcinogenesis stages. METHODS: Single-center cross-sectional study in 64 patients: 19 controls (normal mucosa); 15 with extensive atrophic/metaplastic gastritis; and 30 with early gastric neoplasia (EGN). Seven miRNAs (miR-21, miR-146a, miR-181b, miR-370, miR-375, miR 181b, and miR-490) were quantified by real time-qPCR in peripheral blood and endoscopic biopsy samples. RESULTS: We found a significant upregulation of miR-181b, miR-490, and miR-21 in the EGN mucosa (overexpression 2-14-times higher than controls). We observed a significant underexpression of miR-146a and miR-370 in atrophic/metaplastic gastritis (86 and 66% decrease, p = 0.008 and p = 0.001) and in EGN (89 and 62% reduction, p = 0.034 and p = 0.032) compared with controls. There were no differences between lesions and nonneoplastic mucosa and no dysregulation of plasma miRNAs. CONCLUSION: We found significant dysregulation of 5 miRNAs in gastric carcinogenesis, suggesting a tumor suppressor role for miR-146a and miR-370 and oncogenic potential for miR-21, miR-181, and miR-490. These changes happen diffusely in the gastric mucosa, suggesting a high-risk field defect, which may influence these patients' surveillance.

Leukocyte telomere length and hTERT genetic polymorphism rs2735940 influence the renal cell carcinoma clinical outcome.

Aim: Analysis of the genetic hTERT-1327 C>T (rs2735940) influence on leukocyte telomere length (LTL) and tumor development, progression and overall survival in renal cell carcinoma (RCC) patients. Materials & methods: Using leukocyte DNA of RCC patients and healthy individuals, LTL measurement and allelic discrimination of rs2735940 was performed by real-time PCR. Results: RCC patients showed shorter LTL than healthy individuals and LTL increased with clinical stage. CC+TC genotypes healthy carriers' presented shorter LTL. However, no statistical association between the different genotypes and RCC risk. Nevertheless, CC homozygous presented a reduced time to disease progression and a lower overall survival. The use of hTERT-1327 single nucleotide polymorphism information increased the capacity to predict risk for RCC progression. Conclusion: In fact, in healthy individuals, hTERT-1327 CC+TC genotypes were associated with shorter LTL, and this single nucleotide polymorphism was associated with time to disease progression, being a promising potential prognosis biomarker to be used in the future.

Plasma Extracellular Vesicle-Derived TIMP-1 mRNA as a Prognostic Biomarker in Clear Cell Renal Cell Carcinoma: A Pilot Study.

The tumor microenvironment has gained a lot of attention from the scientific community since it has a proven impact in the development of tumor progression and metastasis. Extracellular vesicles (EVs) are now considered one of the key players of tumor microenvironment modulation. Clear cell renal cell carcinoma (ccRCC) is the most lethal urological neoplasia and presents a high metastatic potential, which reinforces the need for the development of more effective predictive biomarkers. Our goal was to evaluate the applicability of EV-derived matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) as prognostic biomarkers for ccRCC. To do so, we studied the plasma EV content of 32 patients with localized ccRCC and 29 patients with metastatic ccRCC. We observed that patients with localized disease and tumors larger than 7 cm presented higher levels of plasma EV-derived TIMP-1 mRNA when compared with patients presenting smaller tumors (p = 0.020). Moreover, patients with metastatic disease presented higher levels of EV-derived TIMP-1 mRNA when compared with patients with localized disease (p = 0.002) and when we stratified those patients in high and low levels of TIMP-1 EV-derived mRNA, the ones presenting higher levels had a lower overall survival (p = 0.030). EV-derived TIMP-1 mRNA may be a good prognostic biomarker candidate for ccRCC.

Everolimus resistance in clear cell renal cell carcinoma: miRNA-101 and HIF-2α as molecular triggers?

Aim: The majority of clear cell renal cell carcinoma patients develop resistance to mTOR inhibitors. Materials & methods: As an in vitro model four cell lines were used: HKC-8, 786- O, RCC-FG-2 and an everolimus-resistant cell line (786-OR) established during this study. The quantification of miRNA-101 and HIF-2α mRNA levels was assessed by real-time PCR. Results: We observed a significant decrease of miRNA-101 intracellular levels in 786-OR. However, this miRNA presented higher extracellular levels. Additionally, we found a significant increase of HIF-2α in 786-OR. Conclusion: The circulating levels of miRNA-101 may be a potential biomarker of anti-mTOR therapy response and resistance prediction. Moreover, the resistance to mTOR inhibitors seems to be related with the overexpression of HIF-2α.

Creating mindful heroes: a case study with ninth grade students.

The Heroic Imagination Project (HIP) aims to redefine heroism as a set of habits that anyone can achieve. Research findings on the psychological foundations of negative forms of social influence that can lead to bystander behavior are translated into tools that individuals can use in their daily lives. Habits of wise and effective helping behavior are learned, modeled, and encouraged through the training of the "heroic imagination." According to the literature, practicing mindfulness can increase empathy, compassion, and prosocial behaviors. There is empirical evidence that compassion can act as a mediator between mindfulness and prosocial helping behaviors toward strangers, suggesting that mindfulness promotes this behavior and thus helps to overcome the bystander effect. With this hypothesis in mind, we created a program that combined mindfulness and HIP sessions. Five participants volunteered to participate in the "Creating Mindful Heroes" 9-week program. Throughout the sessions, they filled in a diary, and at the end of the program, they answered two feedback questionnaires. They were then invited to participate in individual interviews. The participants reported a positive overall perspective regarding the program, mentioning several improvements in their relationships with their family, peers, and others in society. Moreover, participants reported that the program promoted prosocial behaviors and aided them in developing empathy.

Cancer Cells' Metabolism Dynamics in Renal Cell Carcinoma Patients' Outcome: Influence of GLUT-1-Related hsa-miR-144 and hsa-miR-186.

The cancer cells' metabolism is altered due to deregulation of key proteins, including glucose transporter 1 (GLUT-1), whose mRNA levels are influenced by microRNAs (miRNAs). Renal cell carcinoma (RCC) is the most common and lethal neoplasia in the adult kidney, mostly due to the lack of accurate diagnosis and follow-up biomarkers. Being a metabolic associated cancer, this study aimed to understand the hsa-miR-144-5p and hsa-miR-186-3p's potential as biomarkers of clear cell RCC (ccRCC), establishing their role in its glycolysis status. Using three ccRCC lines, the intra- and extracellular levels of both miRNAs, GLUT-1's mRNA expression and protein levels were assessed. Glucose consumption and lactate production were evaluated as glycolysis markers. A decrease of intracellular levels of these miRNAs and increase of their excretion was observed, associated with an increase of GLUT-1's levels and glycolysis' markers. Through a liquid biopsy approach, we found that RCC patients present higher plasmatic levels of hsa-miR-186-3p than healthy individuals. The Hsa-miR144-5p's higher levels were associated with early clinical stages. When patients were stratified according to miRNAs plasmatic levels, low plasmatic levels of hsa-miR-144-5p and high plasmatic levels of hsa-miR-186-3p (high-risk group) showed the worst overall survival. Thus, circulating levels of these miRNAs may be potential biomarkers of ccRCC prognosis.

Extracellular Vesicles Enriched in hsa-miR-301a-3p and hsa-miR-1293 Dynamics in Clear Cell Renal Cell Carcinoma Patients: Potential Biomarkers of Metastatic Disease.

Clear cell renal cell carcinoma (ccRCC) is the most aggressive subtype of kidney cancer and up to 40% of patients submitted to surgery with a curative intent will relapse. Thus, the aim of this study was to analyze the applicability of an Extracellular vesicle (EV) derived miRNA profile as potential prognosis biomarkers in ccRCC patients. We analyzed a nine-miRNA profile in plasma EVs from 32 ccRCC patients with localized disease (before and after surgery) and in 37 patients with metastatic disease. We observed that the levels of EV-derived hsa-miR-25-3p, hsa-miR-126-5p, hsa-miR-200c-3p, and hsa-miR-301a-3p decreased after surgery, whereas hsa-miR-1293 EV-levels increased. Furthermore, metastatic patients presented higher levels of hsa-miR-301a-3p and lower levels of hsa-miR-1293 when compared to patients with localized disease after surgery. Functional enrichment analysis of the targets of the four miRNAs that decreased after surgery resulted in an enrichment of terms related to cell cycle, proliferation, and metabolism, suggesting that EV-miRNA enrichment in the presence of the tumor could represent an epigenetic mechanism to sustain tumor development. Taken together, these results suggest that EVs content varies depending on the presence or absence of the disease and that an increase of EV-derived hsa-miR-301a-3p, and decrease of EV-derived hsa-miR-1293, may be potential biomarkers of metastatic ccRCC.

miRNAs as potential regulators of mTOR pathway in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most commonly occurring solid cancer of the adult kidney with the majority of RCC cases being detected accidentally. The most aggressive subtype is clear cell RCC (ccRCC). miRNAs, a family of small noncoding RNAs regulating gene expression have been identified as key biological modulators. The von Hippel-Lindau pathway is one of the signaling pathways involved in the pathophysiology of ccRCC. Another oncogenic mechanism involves the activation of PI3K/AKT/mTOR signaling and serves as a central regulator of cell metabolism, proliferation and survival. Several studies have described the involvement of miRNA dysregulation in the pathogenesis and progression of ccRCC. These molecules can be considered as potential diagnostic and prognostic biomarkers, allowing response to therapy to be monitored.