Alterations in SCAI Expression during Cell Plasticity, Fibrosis and Cancer

Hsa_circ_0052611 and mir-767-5p guide the warburg effect, migration, and invasion of BRCA cells through modulating SCAI

Noncoding RNAs are key regulators in the Warburg Effect, an emerging hallmark of cancer. We intended to investigate the role and mechanism of circular RNA hsa_circ_0052611 (circ_0052611) and microRNA (miR)-767-5p in breast cancer (BRCA) hallmarks, especially the Warburg Effect. Expression of circ_0052611 and SCAI was downregulated, and miR-767-5p was upregulated in human BRCA tissues and cells; moreover, circ_0052611 acted as a miR-767-5p sponge to modulate the expression of miR-767-5p-targeted SCAI. Functionally, re-expressing circ_0052611 suppressed migration, invasion, glucose uptake, lactate production, and extracellular acidification rate (ECAR) in BRCA cells, and promoted apoptotic rate. These effects were accompanied by decreased Vimentin, N-cadherin, Bcl-2, and LDHA, and increased E-cadherin and Bax. Consistently, exhausting miR-767-5p exerted similar effects in BRCA cells. High miR-767-5p could counteract the role of circ_0052611 overexpression, and low SCAI likewise blocked the role of miR-767-5p deletion. In vivo, upregulating circ_0052611 delayed tumor growth of BRCA cells by altering miR-767-5p and SCAI expression. circ_0052611/miR-767-5p/SCAI axis might boycott the malignancy of BRCA cells.

Roles of TGF-β signals in tumor microenvironment via regulation of the formation and plasticity of vascular system

Tumor cells evolve in tumor microenvironment composed of multiple cell types. Among these, endothelial cells (ECs) are the major players in tumor angiogenesis, which is a driver of tumor progression and metastasis. Increasing evidence suggests that ECs also contribute to tumor progression and metastasis as they modify their phenotypes to differentiate into mesenchymal cells through a process known as endothelial-mesenchymal transition (EndoMT). This plasticity of ECs is mediated by various cytokines, including transforming growth factor-β (TGF-β), and modulated by other stimuli depending on the cellular contexts. Recent lines of evidence have shown that EndoMT is involved in various steps of tumor progression, including tumor angiogenesis, intravasation and extravasation of cancer cells, formation of cancer-associated fibroblasts, and cancer therapy resistance. In this review, we summarize current updates on EndoMT, highlight the roles of EndoMT in tumor progression and metastasis, and underline targeting EndoMT as a potential therapeutic strategy.

Bridging Gaps in HDR Improvement: The Role of MAD2L2, SCAI, and SCR7

This study aimed to enhance homology-directed repair (HDR) efficiency in CRISPR/Cas-mediated genome editing by targeting three key factors regulating the balance between HDR and non-homologous end joining (NHEJ): MAD2L2, SCAI, and Ligase IV. In order to achieve this, a cellular model using mutated eGFP was designed to monitor HDR events. Results showed that MAD2L2 knockdown and SCR7 treatment significantly improved HDR efficiency during Cas9-mediated HDR repair of the mutated eGFP gene in the HEK293T cell line. Fusion protein Cas9-SCAI did not improve HDR. This study is the first to demonstrate that MAD2L2 knockdown during CRISPR-mediated gene editing in HEK293T cells can increase precise correction by up to 10.2 times. The study also confirmed a moderate but consistent effect of SCR7, an inhibitor of Ligase IV, which increased HDR by 1.7 times. These findings provide valuable insights into improving HDR-based genome editing efficiency.

The key role of microRNA-766 in the cancer development

Cancer is caused by defects in coding and non-coding RNAs. In addition, duplicated biological pathways diminish the efficacy of mono target cancer drugs. MicroRNAs (miRNAs) are short, endogenous, non-coding RNAs that regulate many target genes and play a crucial role in physiological processes such as cell division, differentiation, cell cycle, proliferation, and apoptosis, which are frequently disrupted in diseases such as cancer. MiR-766, one of the most adaptable and highly conserved microRNAs, is notably overexpressed in several diseases, including malignant tumors. Variations in miR-766 expression are linked to various pathological and physiological processes. Additionally, miR-766 promotes therapeutic resistance pathways in various types of tumors. Here, we present and discuss evidence implicating miR-766 in the development of cancer and treatment resistance. In addition, we discuss the potential applications of miR-766 as a therapeutic cancer target, diagnostic biomarker, and prognostic indicator. This may shed light on the development of novel therapeutic strategies for cancer therapy.

A New Role of Acute Phase Proteins: Local Production Is an Ancient, General Stress-Response System of Mammalian Cells

The prevailing general view of acute-phase proteins (APPs) is that they are produced by the liver in response to the stress of the body as part of a systemic acute-phase response. We demonstrated a coordinated, local production of these proteins upon cell stress by the stressed cells. The local, stress-induced APP production has been demonstrated in different tissues (kidney, breast cancer) and with different stressors (hypoxia, fibrosis and electromagnetic heat). Thus, this local acute-phase response (APR) seems to be a universal mechanism. APP production is an ancient defense mechanism observed in nematodes and fruit flies as well. Local APP production at the tissue level is also supported by sporadic literature data for single proteins; however, the complex, coordinated, local appearance of this stress response has been first demonstrated only recently. Although a number of literature data are available for the local production of single acute-phase proteins, their interpretation as a local, coordinated stress response is new. A better understanding of the role of APPs in cellular stress response may also be of diagnostic/prognostic and therapeutic significance.

Immunological Aspects of the Tumor Microenvironment and Epithelial-Mesenchymal Transition in Gastric Carcinogenesis

Infection with Helicobacter pylori, a Gram-negative, microaerophilic pathogen often results in gastric cancer in a subset of affected individuals. This explains why H. pylori is the only bacterium classified as a class I carcinogen by the World Health Organization. Several studies have pinpointed mechanisms by which H. pylori alters signaling pathways in the host cell to cause diseases. In this article, the authors have reviewed 234 studies conducted over a span of 18 years (2002-2020). The studies investigated the various mechanisms associated with gastric cancer induction. For the past 1.5 years, researchers have discovered new mechanisms contributing to gastric cancer linked to H. pylori etiology. Alongside alteration of the host signaling pathways using oncogenic CagA pathways, H. pylori induce DNA damage in the host and alter the methylation of DNA as a means of perturbing downstream signaling. Also, with H. pylori, several pathways in the host cell are activated, resulting in epithelial-to-mesenchymal transition (EMT), together with the induction of cell proliferation and survival. Studies have shown that H. pylori enhances gastric carcinogenesis via a multifactorial approach. What is intriguing is that most of the targeted mechanisms and pathways appear common with various forms of cancer.

Inhibition of Microrna-766-5p Attenuates the Development of Cervical Cancer Through Regulating SCAI

PURPOSE

MicroRNAs (miRNAs) are considered to play anti-tumor roles in cancers. This study is designed to illustrate the role and potential mechanism of miR-766-5p in cervical cancer (CC) progression.

METHODS

MiR-766-5p expression in tissues and serum of CC patients was detected by quantitative reverse-transcription PCR (qRT-PCR). Receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic value of serum miR-766-5p in CC. The 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, wound healing as well as transwell assay were utilized to detect the proliferation, apoptosis, migration and invasion of CC cells, respectively. The interaction between miR-766-5p and SCAI was confirmed by dual-luciferase reporter gene assay. Xenografted tumor model was established to measure the growth of tumor xenograft in vivo.

RESULTS

MiR-766-5p was significantly increased in tissues and serum of CC patients. ROC curve suggested that serum miR-766-5p could serve as a biomarker for the diagnosis of CC. Inhibition of miR-766-5p suppressed the proliferation, migration and invasion, and promoted the apoptosis of CC cells. SCAI was proved to be a target of miR-766-5p. Silencing of SCAI eliminated the inhibiting effects of miR-766-5p inhibitor on the proliferation, migration and invasion of CC cells in vitro. Additionally, down-regulation of SCAI also reversed the inhibitory effect of miR-766-5p inhibitor on the growth of tumor xenograft in vivo.

CONCLUSIONS

Inhibition of miR-766-5p restrains the cell proliferation, migration and invasion, and promotes the apoptosis in CC through negatively regulating SCAI.

Endothelial-to-Mesenchymal Transition (EndoMT): Roles in Tumorigenesis, Metastatic Extravasation and Therapy Resistance

Cancer cells evolve in a very complex tumor microenvironment, composed of several cell types, among which the endothelial cells are the major actors of the tumor angiogenesis. Today, these cells are also characterized for their plasticity, as endothelial cells have demonstrated their potential to modify their phenotype to differentiate into mesenchymal cells through the endothelial-to-mesenchymal transition (EndoMT). This cellular plasticity is mediated by various stimuli including transforming growth factor-β (TGF-β) and is modulated dependently of experimental conditions. Recently, emerging evidences have shown that EndoMT is involved in the development and dissemination of cancer and also in cancer cell to escape from therapeutic treatment. In this review, we summarize current updates on EndoMT and its main induction pathways. In addition, we discuss the role of EndoMT in tumorigenesis, metastasis, and its potential implication in cancer therapy resistance.

Therapeutic Targeting of Fibrotic Epithelial-Mesenchymal Transition-An Outstanding Challenge

Back in 1995, a landmark paper was published, which shaped the fibrosis literature for many years to come. During the characterization of a fibroblast-specific marker (FSP1) in the kidneys, an observation was made, which gave rise to the hypothesis that “fibroblasts in some cases arise from the local conversion of epithelium.” In the following years, epithelial-mesenchymal transition was in the spotlight of fibrosis research, especially in the kidney. However, the hypothesis came under scrutiny following some discouraging findings from lineage tracing experiments and clinical observations. In this review, we provide a timely overview of the current position of the epithelial-mesenchymal transition hypothesis in the context of fibrosis (with a certain focus on renal fibrosis) and highlight some of the potential hurdles and pitfalls preventing therapeutic breakthroughs targeting fibrotic epithelial-mesenchymal transition.