Indicators of microbial-rich environments and the development of papillary thyroid cancer in the California Teachers Study

CircNRCAM up-regulates NRCAM to promote papillary thyroid carcinoma progression

PURPOSE

Papillary Thyroid Carcinoma (PTC) is the most prevalent subtype of Thyroid Carcinoma (THCA), a type of malignancy in the endocrine system. According to prior studies, Neural Cell Adhesion Molecule (NRCAM) has been found to be up-regulated in PTC and stimulates the proliferation and migration of PTC cells. However, the specific mechanism of NRCAM in PTC cells is not yet fully understood. Consequently, this study aimed to investigate the underlying mechanism of NRCAM in PTC cells, the findings of which could provide new insights for the development of potential treatment targets for PTC.

METHODS AND RESULTS

Bioinformatics tools were utilized and a series of experiments were conducted, including Western blot, colony formation, and dual-luciferase reporter assays. The data collected indicated that NRCAM was overexpressed in THCA tissues and PTC cells. Circular RNA NRCAM (circNRCAM) was found to be highly expressed in PTC cells and to positively regulate NRCAM expression. Through loss-of-function assays, both circNRCAM and NRCAM were shown to promote the proliferation, invasion, and migration of PTC cells. Mechanistically, this study confirmed that precursor microRNA-506 (pre-miR-506) could bind with m6A demethylase AlkB Homolog 5 (ALKBH5), leading to its m6A demethylation. It was also discovered that circNRCAM could competitively bind to ALKBH5, which restrained miR-506-3p expression and promoted NRCAM expression.

CONCLUSION

In summary, circNRCAM could up-regulate NRCAM by down-regulating miR-506-3p, thereby enhancing the biological behaviors of PTC cells.

A Potential Nine-lncRNAs Signature Identification and Nomogram Diagnostic Model Establishment for Papillary Thyroid Cancer

The purpose of our current study was to establish a long non-coding RNA(lncRNA) signature and assess its prognostic and diagnostic power in papillary thyroid cancer (PTC). LncRNA expression profiles were obtained from the Cancer Genome Atlas (TCGA). The key module and hub lncRNAs related to PTC were determined by weighted gene co-expression network analysis (WGCNA) and LASSO Cox regression analyses, respectively. Functional enrichment analyses, including Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene set enrichment analysis were implemented to analyze the possible biological processes and signaling pathways of hub lncRNAs. Associations between key lncRNA expressions and tumor-infiltrating immune cells were identified using the TIMER website, and proportions of immune cells in high/low risk score groups were compared. Kaplan-Meier Plotter was used to evaluate the prognostic significance of hub genes in PTC. A diagnostic model was conducted with logistic regression analysis, and its diagnostic performance was assessed by calibration/receiver operating characteristic curves and principal component analysis. A nine-lncRNAs signature (SLC12A5-AS1, LINC02028, KIZ-AS1, LINC02019, LINC01877, LINC01444, LINC01176, LINC01290, and LINC00581) was established in PTC, which has significant diagnostic and prognostic power. Functional enrichment analyses elucidated the regulatory mechanism of the nine-lncRNAs signature in the development of PTC. This signature and expressions of nine hub lncRNAs were correlated with the distributions of tumor infiltrating immune cells. A diagnostic nomogram was also established for PTC. By comparing with the published models with less than or equal to nine lncRNAs, our signature showed a preferable performace for prognosis prediction. In conclusion, our present research established an innovative nine-lncRNAs signature and a six-lncRNAs nomogram that might act as a potential indicator for PTC prognosis and diagnosis, which could be conducive to the PTC treatment.

Role of Advanced Glycation End-Products and Other Ligands for AGE Receptors in Thyroid Cancer Progression

To date, thyroid cancers (TCs) remain a clinical challenge owing to their heterogeneous nature. The etiopathology of TCs is associated not only with genetic mutations or chromosomal rearrangements, but also non-genetic factors, such as oxidative-, nitrosative-, and carbonyl stress-related alterations in tumor environment. These factors, through leading to the activation of intracellular signaling pathways, induce tumor tissue proliferation. Interestingly, the incidence of TCs is often coexistent with various simultaneous mutations. Advanced glycation end-products (AGEs), their precursors and receptors (RAGEs), and other ligands for RAGEs are reported to have significant influence on carcinogenesis and TCs progression, inducing gene mutations, disturbances in histone methylation, and disorders in important carcinogenesis-related pathways, such as PI₃K/AKT/NF-kB, p21/MEK/MPAK, or JAK/STAT, RAS/ERK/p53, which induce synthesis of interleukins, growth factors, and cytokines, thus influencing metastasis, angiogenesis, and cancer proliferation. Precursors of AGE (such as methylglyoxal (MG)) and selected ligands for RAGEs: AS1004, AS1008, and HMGB1 may, in the future, become potential targets for TCs treatment, as low MG concentration is associated with less aggressive anaplastic thyroid cancer, whereas the administration of anti-RAGE antibodies inhibits the progression of papillary thyroid cancer and anaplastic thyroid cancer. This review is aimed at collecting the information on the role of compounds, engaged in glycation process, in the pathogenesis of TCs. Moreover, the utility of these compounds in the diagnosis and treatment of TCs is thoroughly discussed. Understanding the mechanism of action of these compounds on TCs pathogenesis and progression may potentially be the grounds for the development of new treatment strategies, aiming at quality-of-life improvements.

CircRNA circRNA_102171 promotes papillary thyroid cancer progression through modulating CTNNBIP1-dependent activation of β-catenin pathway

Background

As a type of recently discovered noncoding RNA, circular RNAs (circRNAs) exert pivot biological functions in diverse cancers. However, the role of circRNA_102171 in papillary thyroid cancer (PTC) has not been investigated. Our study was focused on the functional investigation toward circRNA_102171 in PTC progression. And we also aimed to reveal its potential molecular mechanism.

Methods

The expression pattern of circRNA_102171 was determined using quantitative polymerase chain reaction (qPCR) in PTC samples and cell lines. Cell proliferation was examined utilizing CCK8, colony formation and EdU incorporation assays. Apoptosis was analyzed by Annexin V/PI staining and FACS detection. Cell migration and invasion was measured using Transwell assay. Tumor growth in vivo was determined through a xenograft assay. RNA-pulldown, RNA-IP (RIP) and RNA-EMSA were used to analyze the interaction between circRNA_102171 and CTNNBIP1.

Results

CircRNA_102171 expression was upregulated in tumor tissues and cell lines. CircRNA_102171 silencing suppressed PTC cell proliferation, migration and invasion while promoting apoptosis. CircRNA_102171 knockdown inhibited PTC growth in vivo. CircRNA_102171 interacted with CTNNBIP1 to block its interaction with the β-catenin/TCF3/TCF4/LEF1 complex, leading to activation of Wnt/β-catenin pathway.

Conclusions

CircRNA_102171 overexpression promotes PTC progression through activating Wnt/β-catenin pathway in a CTNNBIP1-dependent way.

Thyroid cancer risk in airline cockpit and cabin crew: a meta-analysis

BACKGROUND

Airline crew are exposed to ionizing radiation as part of their occupation and have a documented increased risk of melanoma and cataracts. However, whether their occupation predisposes them to an increased risk of thyroid cancer is not established. The purpose of this systematic review and meta-analysis was to assess the risk of thyroid cancer in airline cockpit and cabin crew compared with the general population.

METHODS

The MEDLINE database accessed via PubMed and Cochrane Database were searched. We included cohort studies reporting the standardized incidence ratio (SIR) or standardized mortality ratio (SMR) of thyroid cancers in any flight-based occupation.

RESULTS

Of the 1777 citations retrieved in PubMed, eight studies with a total of 243,088 aircrew members and over 3,334,114 person-years of follow-up were included in this meta-analysis. No relevant studies were identified on Cochrane Database. The overall summary SIR of participants in any flight-based occupation was 1.11 (95% CI, 0.79-1.57; p = 0.613; 6 records). The summary SIR for cockpit crew was 1.21 (95% CI, 0.75-1.95; p = 0.383; 4 records) and the summary SIR for cabin crew was 1.00 (95% CI, 0.60-1.66; p = 0.646; 2 records). The overall summary standardized mortality ratio for airline crew was 1.19 (95% CI, 0.59-2.39; p = 0.773; 2 records).

CONCLUSION

Airline crew were not found to have a significantly elevated risk of thyroid cancer incidence or mortality relative to the general population. Future research should capitalize on the growing occupational cohort dataset and employ innovative methods to quantify lifetime radiation exposure to further assess thyroid cancer risk in airline crew.

LncRNA MEG3 enhances 131I sensitivity in thyroid carcinoma via sponging miR-182

BACKGROUND

Long non-coding RNA (LncRNA) MEG3 has been demonstrated as a tumor suppressor in various cancers, including thyroid carcinoma (TC). However, the detail functions and possible mechanisms of MEG3 in ¹³¹I resistance of TC remain to be uncovered.

METHODS

qRT-PCR was performed for the detection of MEG3 and miR-182 levels. ¹³¹I-resistant TC cells were constructed by continuous exposure to stepwise increased concentrations of ¹³¹I. Western blot assay was used to measure the protein expressions of γ-H2 AX and H2 AX. CCK-8 and flow cytometry assays were carried out for the evaluation of cell viability and apoptosis, respectively. Bioinformatics and dual-luciferse assays were conducted to prove the interaction of MEG3 and miR-182.

RESULTS

MEG3 expression was down-regulated in TC tumor tissues, and the cumulative survival rate was decreased in low MEG3 expression group in TC patients under ¹³¹I treatment. MEG3 expression appeared a decline and miR-182 expression displayed an increase in ¹³¹I-resistant FTC-133 (res-FTC-133) and TPC-1 (res-TPC-1) cells. Moreover, MEG3 overexpression suppressed ¹³¹I-resistant cell viability, promoted apoptosis and induced DNA damage. MEG3 was verified as a molecular sponge for miR-182, and inhibition of miR-182 exerted similar functions as MEG3 overexpression. Furthermore, MEG3 knockdown substantially abrogated the anti-cancer functions of anti-miR-182.

CONCLUSIONS

MEG3 enhanced the radiosensitivity of ¹³¹I in TC cells via sponging miR-182, indicating that MEG3 may act as a potential biomarker and therapeutic target for TC patients with ¹³¹I resistance.

Disease prevalence in a rural Andean population of central Peru: a focus on autoimmune and allergic diseases

Introduction

The hygiene hypothesis, formulated to explain the increased incidence of allergic and autoimmune diseases observed in industrialized countries, remains controversial. We reflected upon this hypothesis during a medical mission to rural and impoverished villages of central Peru.

Materials and methods

The mission was carried out in July 2015 to aid three Andean villages located near Cusco, and comprised 10 American physicians, 4 nurses, and 24 students. After recording the vital signs, patients were triaged by nurses based on the major complaint, visited by physicians, and prescribed medications. Physicians wrote their notes on a one-page form and established diagnoses purely on clinical grounds, without laboratory or imaging testing. Physician notes were then analyzed retrospectively in a de-identified and double-blinded fashion.

Results

A total of 1075 patients (357 men and 718 women) were visited during 5 consecutive clinic days, 840 being adults and 235 <18 years of age. The most common complaints were back pain, stomach pain, headache, and vision loss. Osteoarthritis, gastritis, visual disturbances, and parasitic infections dominated the diagnostic categories. Thirty-seven patients (3 %) were diagnosed with an allergic or autoimmune disease, mainly represented by asthma, rheumatoid arthritis, and Hashimoto’s thyroiditis, a prevalence that was not significantly lower than that reported in industrialized countries.

Conclusions

Although a study of this nature cannot definitively support or refute the hygiene hypothesis, it does provide a novel snapshot of disease prevalence in rural Andean villages of central Peru. The study could serve as a basis to implement basic public health interventions and prepare for future missions to the same or comparable regions.

Electronic supplementary material

The online version of this article (doi:10.1007/s13317-016-0076-z) contains supplementary material, which is available to authorized users.