Oncogenic Role of Exosomal Circular and Long Noncoding RNAs in Gastrointestinal Cancers.

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) are differentially expressed in gastrointestinal cancers. These noncoding RNAs (ncRNAs) regulate a variety of cellular activities by physically interacting with microRNAs and proteins and altering their activity. It has also been suggested that exosomes encapsulate circRNAs and lncRNAs in cancer cells. Exosomes are then discharged into the extracellular environment, where they are taken up by other cells. As a result, exosomal ncRNA cargo is critical for cell-cell communication within the cancer microenvironment. Exosomal ncRNAs can regulate a range of events, such as angiogenesis, metastasis, immune evasion, drug resistance, and epithelial-to-mesenchymal transition. To set the groundwork for developing novel therapeutic strategies against gastrointestinal malignancies, a thorough understanding of circRNAs and lncRNAs is required. In this review, we discuss the function and intrinsic features of oncogenic circRNAs and lncRNAs that are enriched within exosomes.

Interaction of Long Noncoding RNAs and Notch Signaling: Implications for Tissue Homeostasis Loss.

The Notch signaling is a crucial pathway involved in cellular development, progression, and differentiation. Deregulation of Notch signaling pathway commonly impacts tissue homeostasis, being highly associated with proliferative disorders. The long noncoding RNAs (lncRNAs), which are transcripts with more than 200 nucleotides that do not code for proteins, were already described as Notch signaling pathway-interacting molecules. Many of them act as important transcriptional and posttranscriptional regulators, affecting gene expression and targeting other regulatory molecules, such as miRNAs. Due to their strong impact on function and gene expression of Notch-related molecules, lncRNAs influence susceptibility to cancer and other diseases, and can be regarded as potential biomarkers and therapeutic targets. Along this chapter, we summarize the cross talk between the Notch signaling pathway and their most important modulating lncRNAs, as well as the pathological consequences of these interactions, in different tissues.

Polymorphisms in the TGFB1 signal peptide influence human papillomavirus infection and development of cervical lesions.

The main purpose was to assess the effect of c.29C>T and c.74G>C polymorphisms in the TGFB1 signal peptide on HPV infection and development of cervical lesions. Cervical swabs and blood samples were obtained from 349 outpatient women, along with socio-demographic and sexual behavioral data. The study population was stratified by absence or presence of HPV DNA, as tested by PCR, as well as by lesion grade. TGFB1 signal peptide polymorphisms were genotyped using PCR-restriction fragment length polymorphism. HPV DNA was detected in 172 (49.3%) patients. c.74GC and the combined c.29CC+CT/c.74GC genotype were more frequent in infected patients (35.1 and 15.7%) than in uninfected women (6.2 and 14.7%). Accordingly, these genotypes were associated with a higher risk of HPV infection, with odds ratio and 95% confidence interval of 2.81 and 1.35-5.86 (P = 0.004) for c.74GC and 3.14 and 1.42-6.94 (P = 0.004) for the combined genotype, respectively. High-grade lesions were also 2.48 times more likely to occur in c.29CC patients than in c.29TT patients, with a 95% confidence interval of 1.01-6.08 (P = 0.047). The data demonstrate that c.74G>C and c.29C>T polymorphisms are significantly associated with risk of HPV infection and high-grade squamous intraepithelial lesions, respectively. Thus, TGFB1 signal peptide polymorphisms are potential susceptibility markers.

Extracellular vesicles-associated miRNAs in triple-negative breast cancer: from tumor biology to clinical relevance.

Breast cancer (BC), a heterogeneous group of diseases, is the most frequent type and the leading cause of cancer-related death among women worldwide. Tumor heterogeneity directly impacts cancer progression and treatment, as evidenced by the patients´ diverse prognosis and treatment responses across the distinct molecular subtypes. Triple-negative breast cancer (TNBC), which accounts for 10-20% of all diagnosed BC cases, is an aggressive BC subtype with a challenging prognosis. Current treatment options include systemic chemotherapy and/or target therapies based on PARP and PD-L1 inhibitors for eligible patients. MicroRNAs (miRNAs) are important regulatory non-coding RNAs (ncRNAs) in TNBC tumorigenesis. These molecules are present both intracellularly and released into biofluids, packaged into extracellular vesicles (EVs). Emerging evidence indicates that EVs-associated miRNAs (EVs-miRNAs), transferred from parental to recipient cells, are key mediators of cell-to-cell communication. Considering their stability and abundance in several biofluids, these molecules may reflect the epigenomic composition of their tumors of origin and contribute to mediate tumorigenesis, similar to their intracellular counterparts. This review provides the current knowledge on EVs-miRNAs in the TNBC subtype, focusing on their role in regulating mRNA targets involved in tumor phenotypes and their clinical relevance as promising biomarkers in liquid biopsies.

Calcium Phosphate-Based Bioceramics in the Treatment of Osteosarcoma: Drug Delivery Composites and Magnetic Hyperthermia Agents.

The use of biomaterials in medicine is not recent, and in the last few decades, the research and development of biocompatible materials had emerged. Hydroxyapatite (HAp), a calcium phosphate that constitutes a large part of the inorganic composition of human bones and teeth, has been used as an interesting bioceramic material. Among its applications, HAp has been used to carry antitumor drugs, such as doxorubicin, cisplatin, and gemcitabine. Such HAp-based composites have an essential role in anticancer drug delivery systems, including the treatment of osteosarcoma. In addition, the association of this bioceramic with magnetic nanoparticles (MNPs) has also been used as an effective agent of local magnetic hyperthermia. Further, the combined approach of the aforementioned techniques (HAp scaffolds combined with anti-tumor drugs and MNPs) is also an attractive therapeutical alternative. Considering the promising role of the use of bioceramics in modern medicine, we proposed this review, presenting an updated perspective on the use of HAp in the treatment of cancer, especially osteosarcoma. Finally, after giving the current progress in this field, we highlight the urgent need for efforts to provide a better understanding of their potential applications.

Comprehensive analysis of ceRNA networks in HPV16- and HPV18-mediated cervical cancers reveals XIST as a pivotal competing endogenous RNA.

Cervical cancer (CC) is one of the most common cancers in women worldwide, being closely related to high-risk human papillomavirus (HR-HPVs). After a particular HR-HPV infects a cervical cell, transcriptional changes in the host cell are expected, including the regulation of lncRNAs, miRNAs, and mRNAs. Such transcripts may work independently or integrated in complex molecular networks - as in competing endogenous RNA (ceRNA) networks. In our research, we gathered transcriptome data from samples of HPV16/HPV18 cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), from The Cancer Genome Atlas (TCGA) project. Using GDCRNATools, we identified ceRNA networks that differentiate HPV16- from HPV18-mediated CESC. For HPV16-CESC, three lncRNA-mRNA co-expressed pairs were reported, all led by the X-inactive specific transcript (XIST): XIST | DLG5, XIST | LGR4, and XIST | ZNF81. The XIST | LGR4 and XIST | ZNF81 pairs shared 11 miRNAs, suggesting an increased impact on their final biological effect. XIST also stood out as an important lncRNA in HPV18-CESC, leading 35 of the 42 co-expressed pairs. Some mRNAs, such as ADAM9 and SLC38A2, emerged as important players in the ceRNA regulatory networks due to sharing a considerable amount of miRNAs with XIST. Furthermore, some XIST-associated axes, namely XIST | miR-23a-3p | LGR4 and XIST | miR-30b-5p or miR-30c-5p or miR-30e-5p I ADAM9, had a significant impact on the overall survival of HPV16- and HPV18-CESC patients, respectively. Together, these data suggest that XIST has an important role in HPV-mediated tumorigenesis, which may implicate different molecular signatures between HPV16 and HPV18-associated tumors.

FOXP3 Genetic Variants Do Not Impact Circulating and Cervical Interleukin-10 Levels in Human Papillomavirus Infection in Women.

Regulatory T cell (Treg) lineage plays a central role in inflammation and autoimmunity control. Interleukin-10 (IL-10) has been described as a pleiotropic cytokine that is mainly released by CD4+ CD25+ FOXP3+ Treg cells and has a potent immunosuppressive activity. Forkhead box P3 (FOXP3) transcription factor expression is crucial for Treg to function as a suppressor cell, and FOXP3 gene single nucleotide variants (SNVs) have already been shown to influence on viral pathogenesis. This study was conducted to evaluate the plasmatic and cervical levels of IL-10 in human papillomavirus-infected and uninfected patients and investigate whether the FOXP3 intron -1 SNVs rs3761548 and rs2232365 might alter IL-10 secretion. SNVs were genotyped by the characterization of polymerase chain reaction (PCR) products based on sequence-specific enzymatic cleavage using restriction fragment length polymorphism (RFLP) method. IL-10 levels were determined by quantitative enzyme-linked immunosorbent assay (ELISA). In conclusion, the data indicate that there is no association between FOXP3 SNVs and circulating and cervical IL-10 levels. This finding provides a rationale that IL-10 gene activation is independent of FOXP3 transcription factor activities on Treg cells.

From squamous intraepithelial lesions to cervical cancer: Circulating microRNAs as potential biomarkers in cervical carcinogenesis.

Despite the essential role of Human Papillomavirus (HPV) in cervical carcinogenesis, other factors are required for cancer establishment, like miRNAs. Such molecules present a complex biogenesis, being diversely distributed across tissues and biological fluids, as cell-free miRNAs or miRNAs present in extracellular vesicles (EV). After HPV infection, an interplay between HPV and the miRNA network occurs in cervical cells. As the virus persists and cellular transformation occurs, specific patterns of miRNA expression are found in different stages of cervical disease. Thus, defining promising miRNAs/specific miRNA signatures - especially circulating miRNAs - represents an interesting strategy for screening (diagnosis, prognosis, etc.) those stages. Despite the limited number of studies investigating circulating miRNAs in distinct biological fluids, accumulating data have pointed to some promising candidates, both as cell-free or EV-derived miRNAs. Here we highlight some of these promising non-invasive biomarkers and bring attention to the urgent need for efforts in this field.

The role of interleukin 10 in human papilloma virus infection and progression to cervical carcinoma.

Although Human Papillomavirus (HPV) exerts a vital influence on cervical carcinogenesis, other factors influence the development of a squamous intraepithelial lesion (SIL) that may or not progress to cervical cancer. Among several cytokines, Interleukin 10 (IL-10) stands out as an important anti-inflammatory factor, leading to immune system evasion through an immunosuppressive state. In the cervical microenvironment, during different stages of HPV infection, IL-10 production can be induced and maintained by different cell sources, including infected keratinocytes, some subsets of dendritic cells (DC), tumor associated macrophages (TAM), T regulatory cells (Treg) and tumor cells. Further, a wide range of effects can be exerted by IL-10 on different cell populations, such as inhibiting proinflammatory cytokine production, DCs differentiation, antigen presenting function and T-helper 1 (Th1) polarization. IL-10 is one of several cytokines involved in cancer development and sustenance, although its role in cancer is still controversial and poorly understood. However, cervical IL-10 levels tend to increase in parallel to SIL development and are even higher within cervical tumors. Accumulating data have shown that after HPV infection, IL-10 levels are enhanced as a result of HPV E2, E6 and E7 proteins action over IL-10 gene transcription, while IL-10 stimulates HPV E6 and E7 expression. Therefore, this interplay between HPV and IL-10 creates a vicious cycle that could favor an immunosuppressive microenvironment in the cervix, facilitating the progression of a simple HPV infection to SIL or cervical cancer.

IL-10 gene polymorphism c.-592C>A increases HPV infection susceptibility and influences IL-10 levels in HPV infected women.

Interleukin-10 (IL-10) influences HPV infection and viral persistence, favoring cervical immunosuppression and cervical carcinogenesis. IL-10 levels may be influenced by HPV itself and by IL-10 polymorphisms, including rs1800872 (c.-592C>A). Therefore, we evaluated the influence of IL-10 c.-592C>A polymorphism in HPV infection and in IL-10 plasmatic/cervical levels in HPV infected and non-infected women. The study included 174 infected and 186 non-infected patients. Cervical epithelial scrapings were obtained to determine HPV DNA presence PCR. Peripheral blood samples were obtained to determine IL-10 polymorphism by PCR-RFLP, while IL-10 levels were assessed by ELISA. HPV was more prevalent among allele A carriers (p<0.001), with IL-10 c.-592C>A polymorphism being associated with HPV infection. As demonstrated by binary logistic regression analysis, heterozygotes [ORadj=2.081 95% CI (1.222-3.544), p=0.007] and homozygotes [ORadj=3.745 95% CI (1.695-8.271), p=0.001] showed approximately 2 and 4 time's greater odds, respectively, of presenting HPV when compared to CC patients. Moreover, HPV infected patients carrying polymorphic allele A showed higher IL-10 cervical levels (p=0.039). Binary logistic regression analysis demonstrated that IL-10 cervical levels were not independently associated to CA+AA genotypes (p=0.162), neither to HPV's presence (p=0.061), thus IL-10 cervical levels are possibly increased because of both HPV and allele A presence. Taken together, these findings suggest that IL-10 c.-592C>A polymorphism is independently associated with HPV infection susceptibility exerting influence on IL-10 cervical levels in HPV infected women, thus contributing to cervical carcinogenesis.