Gene expression in papillary thyroid carcinoma reveals highly consistent profiles

Gas1-Mediated Suppression of Hepatoblastoma Tumorigenesis

Hepatoblastoma (HB), the most common pediatric liver cancer, is associated with dysregulated Wnt/β-catenin, Hippo, and/or nuclear factor erythroid 2 ligand 2/nuclear respiratory factor 2 (NFE2L2/NRF2) pathways. In mice, pairwise combinations of oncogenically active forms of the terminal transcription factors of these pathways, namely, β-catenin (B), Yes-associated protein (YAP; Y), and Nrf2 (N), generate HBs, with the triple combination (B + Y + N) being particularly potent. Each tumor group alters the expression of thousands of B-, Y-, and N-driven unique and common target genes. The identification of those most involved in transformation might reveal mechanisms and opportunities for therapy. Herein, transcription profiling of >60 murine HBs revealed a common set of 22 "BYN" genes similarly deregulated in all cases. Most were associated with multiple cancer hallmarks, and their expression often correlated with survival in HBs, hepatocellular carcinomas, and other cancers. Among the most down-regulated of these genes was Gas1, which encodes a glycosylphosphatidylinositol-linked outer membrane protein. The restoration of Gas1 expression impaired B + Y + N-driven HB tumor growth in vivo and in HB-derived immortalized BY and BYN cell lines in vitro in a manner that requires membrane anchoring of the protein via its glycosylphosphatidylinositol moiety, implicating Gas1 as a proximal mediator of HB pathogenesis and validating the BYN gene set as deserving of additional scrutiny in future studies.

The mammalian acid chitinase promotes oncogenic properties of thyroid cancer cells through the JAK2/STAT3 pathway

Objective

Mammalian acid chitinase (AMCase; CHIA) has potential as a biomarker and drug target in the fields of medicine and pharmacology, and its role in inhibiting tumor growth and Th2 cell-mediated asthma-related inflammation has become a research hotspot. However, the role of CHIA in thyroid cancer is unclear.

Methods

Tissue microarrays and thyroid cancer cell lines were used to detect CHIA expression and determine its clinical relevance. CHIA gene expression was altered in thyroid cancer cells to examine the effects of CHIA expression on the biological behavior of thyroid cancer cells, and the related molecular mechanisms involved were explored.

Results

We first examined CHIA expression in a thyroid tissue microarray using immunohistochemistry. We found that CHIA was significantly upregulated in thyroid cancer tissues relative to paired thyroid cancer adjacent tissues. After correlation analysis, we found that upregulated CHIA expression correlated with the tumor-node-metastasis (TNM) stage of patients with thyroid cancer. Similarly, CHIA expression was significantly higher in the thyroid cancer cell lines BCPAP, TPC-1, KTC-1 and FTC133 than in the human normal thyroid epithelial cell line Nthy-ori-3-1. CHIA promotes proliferation, migration and invasion; inhibits thyroid cancer cell apoptosis; and regulates markers of proliferation and epithelial-mesenchymal transition. Mechanistically, CHIA activated the JAK2/STAT3 signaling pathway in thyroid cancer cells.

Conclusions

CHIA upregulation promoted the proliferation, migration and invasion of thyroid cancer cells through JAK2/STAT3 signaling pathway activation. Therefore, CHIA could represent a potential new oncoprotein for patients with thyroid cancer.

Estrogen enhances the proliferation, migration, and invasion of papillary thyroid carcinoma via the ERα/KRT19 signaling axis

BACKGROUND

Estrogen is thought to be the reason for the higher prevalence of papillary thyroid carcinoma (PTC) in fertile women; however, more study is required to completely comprehend how estrogen affects PTC development at the cellular level. Therefore, we combined Oxford Nanopore Technologies (ONT) sequencing to explore molecular markers of PTC and to investigate the molecular mechanisms by which estrogen promotes PTC development.

METHODS

The expression levels of ESR1 (ERα) and KRT19 in normal thyroid tissues and cancer tissues as well as in different cancer stages, races, genders, age groups, histological subtypes and nodular metastasis status of the TCGA database were analyzed online by Ualcan; the relationship between ESR1, KRT19 and the survival of THCA patients was analyzed. A PTC xenograft tumor model was established. An ERα specific inhibitor (MPP) was administered and an EDU cell proliferation assay was used to verify the effect of estrogen on PTC proliferation. KRT19 was knocked down in KTC-1 cells, and the proliferation, migration, and invasion abilities of PTC cells were determined using CCK-8, immunofluorescence labeling, Western blot for EMT-related proteins, scratch assay, and Transwell assay. The role of ERα in relation to KRT19 was investigated by Western blot and immunofluorescence. The effects of ERα/KRT19 signaling axis on the proliferation, migration and invasion ability of PTC cells were evaluated using EDU cell proliferation assay and Transwell. Using ONT sequencing, 15 pairs of PTC tissue and paracancer tissue samples were collected. A PPI network was constructed to validate the differential expression of KRT19 in combination with biosignature analysis, and the protein interaction between KRT19 and ESR1 was verified using STRING.

RESULTS

Ualcan showed that the expression of ESR1 and KRT19 was higher in THCA tissues than in normal thyroid tissues. E2 activation of ERα promoted the growth of PTC cells and tissues. si-KRT19 inhibited the proliferation, migration and invasion of PTC cells. KRT19 together with ERα formed the ERα/KRT19 signaling axis. E2 activation of the ERα/KRT19 signaling axis promoted the proliferation, migration, and invasion of PTC cells. ONT sequencing and STRING website verified that KRT19 is significantly differentially expressed in PTC and that ESR1 and KRT19 have protein interactions and are related to the estrogen signaling pathway.

CONCLUSIONS

Using public databases, RNA sequencing, and bioinformatics, we discovered that E2 stimulates the ERα/KRT19 signaling axis to stimulate PTC proliferation, migration, and invasion.

The selenoenzyme type I iodothyronine deiodinase: a new tumor suppressor in ovarian cancer

The selenoenzyme type I iodothyronine deiodinase (DIO1) catalyzes removal of iodine atoms from thyroid hormones. Although DIO1 action is reported to be disturbed in several malignancies, no work has been conducted in high-grade serous ovarian carcinoma (HGSOC), the most lethal gynecologic cancer. We studied DIO1 expression in HGSOC patients [The Cancer Genome Atlas (TCGA) data and tumor tissues], human cell lines (ES-2 and Kuramochi), normal Chinese hamster ovarian cells (CHO-K1), and normal human fallopian tube cells (FT282 and FT109). To study its functional role, DIO1 was overexpressed, inhibited [by propylthiouracil (PTU)], or knocked down (KD), and cell count, proliferation, apoptosis, cell viability, and proteomics analysis were performed. Lower DIO1 levels were observed in HGSOC compared to normal cells and tissues. TCGA analyses confirmed that low DIO1 mRNA expression correlated with worse survival and therapy resistance in patients. Silencing or inhibiting the enzyme led to enhanced ovarian cancer proliferation, while an opposite effect was shown following DIO1 ectopic expression. Proteomics analysis in DIO1-KD cells revealed global changes in proteins that facilitate tumor metabolism and progression. In conclusion, DIO1 expression and ovarian cancer progression are inversely correlated, highlighting a tumor suppressive role for this enzyme and its potential use as a biomarker in this disease.

MET-receptor targeted fluorescent imaging and spectroscopy to detect multifocal papillary thyroid cancer

PURPOSE

Multifocal disease in PTC is associated with an increased recurrence rate. Multifocal disease (MD) is underdiagnosed with the current gold standard of pre-operative ultrasound staging. Here, we evaluate the use of EMI-137 targeted molecular fluorescence-guided imaging (MFGI) and spectroscopy as a tool for the intra-operative detection of uni- and multifocal papillary thyroid cancer (PTC) aiming to improve disease staging and treatment selection.

METHODS

A phase-1 study (NCT03470259) with EMI-137 was conducted to evaluate the possibility of detecting PTC using MFGI and quantitative fiber-optic spectroscopy.

RESULTS

Fourteen patients underwent hemi- or total thyroidectomy (TTX) after administration of 0.09 mg/kg (n = 1), 0.13 mg/kg (n = 8), or 0.18 mg/kg (n = 5) EMI-137. Both MFGI and spectroscopy could differentiate PTC from healthy thyroid tissue after administration of EMI-137, which binds selectively to MET in PTC. 0.13 mg/kg was the lowest dosage EMI-137 that allowed for differentiation between PTC and healthy thyroid tissue. The smallest PTC focus detected by MFGI was 1.4 mm. MFGI restaged 80% of patients from unifocal to multifocal PTC compared to ultrasound.

CONCLUSION

EMI-137-guided MFGI and spectroscopy can be used to detect multifocal PTC. This may improve disease staging and treatment selection between hemi- and total thyroidectomy by better differentiation between unifocal and multifocal disease.

TRIAL REGISTRATION

NCT03470259.

LINC00092 Enhances LPP Expression to Repress Thyroid Cancer Development via Sponging miR-542-3p

LINC00092 is poorly expressed in Thyroid cancer (TC), while its role in TC tumorigenesis is still elusive. This study aimed to reveal the role and regulatory mechanism of LINC00092 in TC.RNA immunoprecipitation and dual luciferase reporter assays were employed to ascertain the relationships among lipoma preferred partner (LPP), miR-542-3p, and LINC00092. qRT-PCR analysis was performed to detect their expression levels in TC. LPP protein productions were evaluated via western blotting. CCK-8, transwell, and colony formation assays were done to estimate TC cells' biological functions. A murine xenograft model was built to observe tumor formation in vivo.LINC00092 overexpression decreased the expression levels of miR-542-3p, and LPP was targeted by miR-542-3p. In TC cells and tissues, the elevation of miR-542-3p, and low amounts of LINC00092 and LPP can be observed. Both LINC00092 and SPAG6 were considered as the antineoplastic factors in TC since their overexpression dramatically repressed TC cells' invasive and proliferative potentials, while miR-542-3p exerted the opposite functions in TC. The ectopic expression of LINC00092 also suppressed tumor growth in vivo. In addition, it revealed that miR-542-3p upregulation reversed LINC00092 overexpression-mediated effects on TC cells. At the same time, the enhanced influences of TC cells caused by miR-542-3p upregulation could be attenuated by the enforced LPP.This study innovatively reveals that LINC00092 acts as an antineoplastic lncRNA to restrain the development of TC via regulating miR-542-3p/LPP. The findings of this study may provide a prospective drug target on LINC00092/miR-542-3p/LPP axis for the treatment of TC.

Roles and signaling pathways of CITED1 in tumors: overview and novel insights

CBP/p300 interacting transactivator with Glu/Asp-rich carboxy-terminal domain 1 (CITED1) is a transcriptional activator belonging to the non-DNA-binding transcription co-regulator family. It regulates diverse pathways, including the transforming growth factor/bone morphogenetic protein/SMAD, estrogen, Wnt-β-catenin, and androgen-AR signaling pathways, by binding to CBP/p300 co-activators through its conserved transactivation domain CR2. CITED1 plays an important role in embryonic development and a certain regulatory role in the occurrence and development of various tumors. In this article, the biological characteristics, expression regulation, participating signaling pathways, and potential roles of CITED1 in the clinical diagnosis and treatment of tumors are reviewed.

Progress in Thyroid Cancer Genomics: A 40-Year Journey

Background: Very little was known about the molecular pathogenesis of thyroid cancer until the late 1980s. As part of the Centennial celebration of the American Thyroid Association, we review the historical discoveries that contributed to our current understanding of the genetic underpinnings of thyroid cancer. Summary: The pace of discovery was heavily dependent on scientific breakthroughs in nucleic acid sequencing technology, cancer biology, thyroid development, thyroid cell signaling, and growth regulation. Accordingly, we attempt to link the primary observations on thyroid cancer molecular genetics with the methodological and scientific advances that made them possible. Conclusions: The major genetic drivers of the common forms of thyroid cancer are now quite well established and contribute to a significant extent to how we diagnose and treat the disease. However, many challenges remain. Future work will need to unravel the complexity of thyroid cancer ecosystems, which is likely to be a major determinant of their biological behavior and on how they respond to therapy.

Insight of novel biomarkers for papillary thyroid carcinoma through multiomics

INTRODUCTION

The overdiagnosing of papillary thyroid carcinoma (PTC) in China necessitates the development of an evidence-based diagnosis and prognosis strategy in line with precision medicine. A landscape of PTC in Chinese cohorts is needed to provide comprehensiveness.

METHODS

6 paired PTC samples were employed for whole-exome sequencing, RNA sequencing, and data-dependent acquisition mass spectrum analysis. Weighted gene co-expression network analysis and protein-protein interactions networks were used to screen for hub genes. Moreover, we verified the hub genes' diagnostic and prognostic potential using online databases. Logistic regression was employed to construct a diagnostic model, and we evaluated its efficacy and specificity based on TCGA-THCA and GEO datasets.

RESULTS

The basic multiomics landscape of PTC among local patients were drawn. The similarities and differences were compared between the Chinese cohort and TCGA-THCA cohorts, including the identification of PNPLA5 as a driver gene in addition to BRAF mutation. Besides, we found 572 differentially expressed genes and 79 differentially expressed proteins. Through integrative analysis, we identified 17 hub genes for prognosis and diagnosis of PTC. Four of these genes, ABR, AHNAK2, GPX1, and TPO, were used to construct a diagnostic model with high accuracy, explicitly targeting PTC (AUC=0.969/0.959 in training/test sets).

DISCUSSION

Multiomics analysis of the Chinese cohort demonstrated significant distinctions compared to TCGA-THCA cohorts, highlighting the unique genetic characteristics of Chinese individuals with PTC. The novel biomarkers, holding potential for diagnosis and prognosis of PTC, were identified. Furthermore, these biomarkers provide a valuable tool for precise medicine, especially for immunotherapeutic or nanomedicine based cancer therapy.

The Emerging Role of m6A Modification in Endocrine Cancer

With the development of RNA modification research, N6-methyladenosine (m6A) is regarded as one of the most important internal epigenetic modifications of eukaryotic mRNA. It is also regulated by methylase, demethylase, and protein preferentially recognizing the m6A modification. This dynamic and reversible post-transcriptional RNA alteration has steadily become the focus of cancer research. It can increase tumor stem cell self-renewal and cell proliferation. The m6A-modified genes may be the primary focus for cancer breakthroughs. Although some endocrine cancers are rare, they may have a high mortality rate. As a result, it is critical to recognize the significance of endocrine cancers and identify new therapeutic targets that will aid in improving disease treatment and prognosis. We summarized the latest experimental progress in the m6A modification in endocrine cancers and proposed the m6A alteration as a potential diagnostic marker for endocrine malignancies.

Molecular testing of cytology specimens: overview of assay selection with focus on lung, salivary gland, and thyroid testing

Ancillary and molecular testing of cytopathology specimens has emerged as a reliable and useful tool to provide diagnostic information and treatment-related biomarker status for the management of cancer patients. The cytology specimens obtained through minimally invasive means have proven suitable testing substrates for a variety of ancillary tests, including immunohistochemistry, fluorescence in situ hybridization, as well as polymerase chain reaction and next generation sequencing molecular techniques. By focusing specifically on the cytology specimen, this review provides an overview of basic testing considerations and assay selection in addition to updates on the ancillary testing of cytologic tumor specimens from the lung, salivary gland, and thyroid.

Genome-wide cross-cancer analysis illustrates the critical role of bimodal miRNA in patient survival and drug responses to PI3K inhibitors

Heterogeneity of cancer means many tumorigenic genes are only aberrantly expressed in a subset of patients and thus follow a bimodal distribution, having two modes of expression within a single population. Traditional statistical techniques that compare sample means between cancer patients and healthy controls fail to detect bimodally expressed genes. We utilize a mixture modeling approach to identify bimodal microRNA (miRNA) across cancers, find consistent sources of heterogeneity, and identify potential oncogenic miRNA that may be used to guide personalized therapies. Pathway analysis was conducted using target genes of the bimodal miRNA to identify potential functional implications in cancer. In vivo overexpression experiments were conducted to elucidate the clinical importance of bimodal miRNA in chemotherapy treatments. In nine types of cancer, tumors consistently displayed greater bimodality than normal tissue. Specifically, in liver and lung cancers, high expression of miR-105 and miR-767 was indicative of poor prognosis. Functional pathway analysis identified target genes of miR-105 and miR-767 enriched in the phosphoinositide-3-kinase (PI3K) pathway, and analysis of over 200 cancer drugs in vitro showed that drugs targeting the same pathway had greater efficacy in cell lines with high miR-105 and miR-767 levels. Overexpression of the two miRNA facilitated response to PI3K inhibitor treatment. We demonstrate that while cancer is marked by considerable genetic heterogeneity, there is between-cancer concordance regarding the particular miRNA that are more variable. Bimodal miRNA are ideal biomarkers that can be used to stratify patients for prognosis and drug response in certain types of cancer.

Bimodal genes can be defined as those having two modes of expression within the same population. A variety of statistical methodologies have been employed to assess bimodal gene expression, but current methods and their applications have been limited. Given the advances in next-generation sequencing as well as the extensive regulatory role of miRNA, assessing bimodality in miRNA-seq data can greatly broaden our understanding of factors underlying tumor progression. The goal of the current study was to utilize a novel mixture modeling approach to identify bimodal miRNA and then demonstrate their importance in cancer by evaluating their ability to predict overall survival and drug response. Our results showed that high levels of bimodal miRNA expression was characteristic of cancer. Additionally, several bimodal miRNA were common to multiple cancer types, suggesting that certain miRNA consistently account for tumor heterogeneity and may be involved in general oncogenic processes. Our study points to the potential of bimodal miRNA to facilitate precise prognostic evaluation and effective treatment strategies.

Intraoperative MET-receptor targeted fluorescent imaging and spectroscopy for lymph node detection in papillary thyroid cancer: novel diagnostic tools for more selective central lymph node compartment dissection

Purpose

Patients undergoing prophylactic central compartment dissection (PCLND) for papillary thyroid cancer (PTC) are often overtreated. This study aimed to determine if molecular fluorescence-guided imaging (MFGI) and spectroscopy can be useful for detecting PTC nodal metastases (NM) and to identify negative central compartments intraoperatively.

Methods

We used a data-driven prioritization strategy based on transcriptomic profiles of 97 primary PTCs and 80 normal thyroid tissues (NTT) to identify tumor-specific antigens for a clinically available near-infrared fluorescent tracer. Protein expression of the top prioritized antigen was immunohistochemically validated with a tissue microarray containing primary PTC (n = 741) and NTT (n = 108). Staining intensity was correlated with 10-year locoregional recurrence-free survival (LRFS). A phase 1 study (NCT03470259) with EMI-137, targeting MET, was conducted to evaluate safety, optimal dosage for detecting PTC NM with MFGI, feasibility of NM detection with quantitative fiber-optic spectroscopy, and selective binding of EMI-137 for MET.

Results

MET was selected as the most promising antigen. A worse LRFS was observed in patients with positive versus negative MET staining (81.9% versus 93.2%; p = 0.02). In 19 patients, no adverse events related to EMI-137 occurred. 0.13 mg/kg EMI-137 was selected as optimal dosage for differentiating NM from normal lymph nodes using MFGI (p < 0.0001) and spectroscopy (p < 0.0001). MFGI identified 5/19 levels (26.3%) without NM. EMI-137 binds selectively to MET.

Conclusion

MET is overexpressed in PTC and associated with increased locoregional recurrence rates. Perioperative administration of EMI-137 is safe and facilitates NM detection using MFGI and spectroscopy, potentially reducing the number of negative PCLNDs with more than 25%.

Clinical trial registration.

NCT03470259.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-022-05763-3.

Identification of DPP4/CTNNB1/MET as a Theranostic Signature of Thyroid Cancer and Evaluation of the Therapeutic Potential of Sitagliptin

Simple Summary

In recent years, the incidence of thyroid cancer has been increasing globally, with papillary thyroid cancer (PTCa) being the most prevalent pathological type. Although PTCa has been regarded to be slow growing and has a good prognosis, in some cases, PTCa can be aggressive and progress despite surgery and radioactive iodine treatment. Therefore, searching for new targets and therapies is required. We utilized bioinformatics analyses to identify critical theranostic markers for PTCa. We found that DPP4/CTNNB1/MET is an oncogenic signature that is overexpressed in PTCa and associated with disease progression, distant metastasis, treatment resistance, immuno-evasive phenotypes, and poor clinical outcomes. Interestingly, our in silico molecular docking results revealed that sitagliptin, an antidiabetic drug, has strong affinities and potential for targeting DPP4/CTNNB1/MET signatures, even higher than standard inhibitors of these genes. Collectively, our findings suggest that sitagliptin could be repurposed for treating PTCa.

Abstract

In recent years, the incidence of thyroid cancer has been increasing globally, with papillary thyroid cancer (PTCa) being the most prevalent pathological type, accounting for approximately 80% of all cases. Although PTCa has been regarded to be slow growing and has a good prognosis, in some cases, PTCa can be aggressive and progress despite surgery and radioactive iodine treatment. In addition, most cancer treatment drugs have been shown to be cytotoxic and nonspecific to cancer cells, as they also affect normal cells and consequently cause harm to the body. Therefore, searching for new targets and therapies is required. Herein, we explored a bioinformatics analysis to identify important theranostic markers for THCA. Interestingly, we identified that the DPP4/CTNNB1/MET gene signature was overexpressed in PTCa, which, according to our analysis, is associated with immuno-invasive phenotypes, cancer progression, metastasis, resistance, and unfavorable clinical outcomes of thyroid cancer cohorts. Since most cancer drugs were shown to exhibit cytotoxicity and to be nonspecific, herein, we evaluated the anticancer effects of the antidiabetic drug sitagliptin, which was recently shown to possess anticancer activities, and is well tolerated and effective. Interestingly, our in silico molecular docking results exhibited putative binding affinities of sitagliptin with DPP4/CTNNB1/MET signatures, even higher than standard inhibitors of these genes. This suggests that sitagliptin is a potential THCA therapeutic, worthy of further investigation both in vitro and in vivo and in clinical settings.

Gene expression profile in functioning and non-functioning nodules of autonomous multinodular goiter from an area of iodine deficiency: unexpected common characteristics between the two entities

PURPOSE

Toxic multinodular goiter is a heterogeneous disease associated with hyperthyroidism frequently detected in areas with deficient iodine intake, and functioning and non-functioning nodules, characterized by increased proliferation but opposite functional activity, may coexist in the same gland. To understand the distinct molecular pathology of each entity present in the same gland, the gene expression profile was evaluated by using the Affymetrix technology.

METHODS

Total RNA was extracted from nodular and healthy tissues of two patients and double-strand cDNA was synthesized. Biotinylated cRNA was obtained and, after chemical fragmentation, was hybridized on U133A and B arrays. Each array was stained and the acquired images were analyzed to obtain the expression levels of the transcripts. Both functioning and non-functioning nodules were compared versus healthy tissue of the corresponding patient.

RESULTS

About 16% of genes were modulated in functioning nodules, while in non-functioning nodules only 9% of genes were modulated with respect to the healthy tissue. In functioning nodules of both patients and up-regulation of cyclin D1 and cyclin-dependent kinase inhibitor 1 was observed, suggesting the presence of a possible feedback control of proliferation. Complement components C1s, C7 and C3 were down-regulated in both types of nodules, suggesting a silencing of the innate immune response. Cellular fibronectin precursor was up-regulated in both functioning nodules suggesting a possible increase of endothelial cells. Finally, Frizzled-1 was down-regulated only in functioning nodules, suggesting a role of Wnt signaling pathway in the proliferation and differentiation of these tumors. None of the thyroid-specific gene was deregulated in microarray analysis.

CONCLUSION

In conclusion, the main finding from our data is a similar modulation for both kinds of nodules in genes possibly implicated in thyroid growth.

DPP4 gene silencing inhibits proliferation and epithelial-mesenchymal transition of papillary thyroid carcinoma cells through suppression of the MAPK pathway

PURPOSE

Papillary thyroid carcinoma (PTC) is characterized by epithelial malignancy and is the most prevalent thyroid neoplasm with the best overall prognosis. Notably, recently published studies have indicated remarkably high expression of dipeptidyl peptidase 4 (DPP4) in PTC. However, the underlying molecular mechanism and regulatory factors of PTC progression remain unknown. Therefore, the current study aimed to elucidate the effects of DPP4 gene silencing on PTC and further investigated whether the mechanism of PTC progression is related to the mitogen-activated protein kinase (MAPK) pathway.

METHODS

Herein, microarray-based gene expression profiling of PTC was conducted to identify the differentially expressed genes between tumor thyroid tissue and normal thyroid tissue as well as the underlying signaling pathway involved in PTC pathogenesis. Moreover, protein quantification was performed to assess the protein expression of DPP4 in PTC tissues collected from 65 patients. In addition, DPP4 was silenced in PTC cell lines (GLAG-66 and TPC-1) through siRNA-mediated DPP4 knockdown or sitagliptin (inhibitor of DPP4)-mediated inhibition to assess the effects of DPP4 on the MAPK pathway and cellular processes, including proliferation, apoptosis, and epithelial-to-mesenchymal transition (EMT).

RESULTS

Intriguingly, our data revealed markedly high expression of DPP4 in PTC tissues. However, in GLAG-66 and TPC-1 cells, the silencing of DPP4 resulted in significantly reduced expression of ERK1/2, JNK1, P38 MAPK, VEGF, FGFR-1, TGF-β1, Snail, HIF-1α, N-cadherin, and Bcl-2 along with reduced phosphorylation of ERK1/2, JNK1, and P38 MAPK, whereas the expression of E-cadherin and Bax was increased. Furthermore, DPP4 silencing was found to hinder cell proliferation and potentiate cell apoptosis.

CONCLUSION

Collectively, the present study demonstrated that DPP4 gene silencing inhibits PTC cell proliferation and EMT and promotes cell apoptosis via suppression of the MAPK pathway, thus highlighting a possible regulatory pathway in PTC progression.

Identification of ferroptosis genes in immune infiltration and prognosis in thyroid papillary carcinoma using network analysis

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer. While many patients survive, a portion of PTC cases display high aggressiveness and even develop into refractory differentiated thyroid carcinoma. This may be alleviated by developing a novel model to predict the risk of recurrence. Ferroptosis is an iron-dependent form of regulated cell death (RCD) driven by lethal accumulation of lipid peroxides, is regulated by a set of genes and shows a variety of metabolic changes. To elucidate whether ferroptosis occurs in PTC, we analyse the gene expression profiles of the disease and established a new model for the correlation.

METHODS

The thyroid carcinoma (THCA) datasets were downloaded from The Cancer Genome Atlas (TCGA), UCSC Xena and MisgDB, and included 502 tumour samples and 56 normal samples. A total of 60 ferroptosis related genes were summarised from MisgDB database. Gene set enrichment analysis (GSEA) and Gene set variation analysis (GSVA) were used to analyse pathways potentially involving PTC subtypes. Single sample GSEA (ssGSEA) algorithm was used to analyse the proportion of 28 types of immune cells in the tumour immune infiltration microenvironment in THCA and the hclust algorithm was used to conduct immune typing according to the proportion of immune cells. Spearman correlation analysis was performed on the ferroptosis gene expression and the correlation between immune infiltrating cells proportion. We established the WGCNA to identify genes modules that are highly correlated with the microenvironment of immune invasion. DEseq2 algorithm was further used for differential analysis of sequencing data to analyse the functions and pathways potentially involving hub genes. GO and KEGG enrichment analysis was performed using Clusterprofiler to explore the clinical efficacy of hub genes. Univariate Cox analysis was performed for hub genes combined with clinical prognostic data, and the results was included for lasso regression and constructed the risk regression model. ROC curve and survival curve were used for evaluating the model. Univariate Cox analysis and multivariate Cox analysis were performed in combination with the clinical data of THCA and the risk score value, the clinical efficacy of the model was further evaluated.

RESULTS

We identify two subtypes in PTC based on the expression of ferroptosis related genes, with the proportion of cluster 1 significantly higher than cluster 2 in ferroptosis signature genes that are positively associated. The mutations of Braf and Nras are detected as the major mutations of cluster 1 and 2, respectively. Subsequent analyses of TME immune cells infiltration indicated cluster 1 is remarkably richer than cluster 2. The risk score of THCA is in good performance evaluated by ROC curve and survival curve, in conjunction with univariate Cox analysis and multivariate Cox analysis results based on the clinical data shows that the risk score of the proposed model could be used as an independent prognostic indicator to predict the prognosis of patients with papillary thyroid cancer.

CONCLUSIONS

Our study finds seven crucial genes, including Ac008063.2, Apoe, Bcl3, Acap3, Alox5ap, Atxn2l and B2m, and regulation of apoptosis by parathyroid hormone-related proteins significantly associated with ferroptosis and immune cells in PTC, and we construct the risk score model which can be used as an independent prognostic index to predict the prognosis of patients with PTC.

Collagen prolyl 4-hydroxylases modify tumor progression

Collagen is the main component of the extracellular matrix. Hydroxylation of proline residues on collagen, catalyzed by collagen prolyl 4-hydroxylase (C-P4H), is essential for the stability of the collagen triple helix. Vertebrate C-P4H is an α2β2 tetramer with three isoenzymes differing in the catalytic α-subunits, which are encoded by P4HA1, P4HA2, and P4HA3 genes. In contrast, β-subunit is encoded by a single gene P4HB. The expressions of P4HAs and P4HB are regulated by multiple cellular factors, including cytokines, transcription factors, and microRNAs. P4HAs and P4HB are highly expressed in many tumors and participate in cancer progression. Several inhibitors of P4HAs and P4HB have been confirmed to have anti-tumor effects, suggesting that targeting C-P4H is a feasible strategy for cancer treatment. Here, we summarize recent progresses on the function and expression of regulatory mechanisms of C-P4H in cancer progression and point out the potential development of therapeutic strategies in targeting C-P4H in the future.

Increased gene expression of TIMP1 and CHI3L1 in fine-needle aspiration biopsy samples from papillary thyroid cancer as compared to benign nodules

BACKGROUND

Thyroid nodules are common ultrasound findings with malignancy rate 7%-15%. Our objective was to assess the relative expression of the tissue inhibitor of metalloproteinase-1 gene (TIMP1) and chitinase-3-like protein 1 gene (CHI3L1) in fine-needle aspiration biopsy (FNAB) washouts and the serum levels of their protein products (TIMP-1 and chitinase-3-like protein 1 known as YKL-40) in patients with papillary thyroid cancer (PTC) and patients with benign nodules. Furthermore, the correlation between gene expression and circulating protein product was evaluated.

METHODS

Eighty patients who underwent FNAB in one tertiary center were recruited in the study. Forty with Bethesda V and VI nodules were operated and PTC was confirmed. The other 40 patients were with Bethesda II nodules. TIMP-1 and YKL-40 serum levels were measured in all subjects. The TIMP1 and CHI3L1 expression was assessed in FNAB washouts from 20 PTC patients and 20 benign cases using quantitative PCR.

RESULTS

The relative expression of TIMP1 and CHI3L1 was significantly higher in the PTC group than in the benign group (p < .001 for TIMP1; p = .018 for CHI3L1). The PTC patients had higher serum TIMP-1 than the patients with benign nodules (p = .036). We did not find significant difference in the YKL-40 level between the two groups. TIMP1 and CHI3L1 expression did not correlate with the serum levels of their protein products.

CONCLUSION

FNAB washouts could be used for identification of diagnostic markers. The increased TIMP1 and CHI3L1 expression implies a role of these genes in the PTC carcinogenesis.

Long non-coding RNA HOTAIR/microRNA-761 sponge regulates PPME1 and further influences cell biological functions in thyroid carcinoma

BACKGROUND

Most well-differentiated thyroid carcinomas display good therapeutic outcomes, but there are still some patients who are not sensitive to the general treatments lose their treatment opportunities. Thus, it is important to understand the molecular mechanisms that cause thyroid carcinoma, so as to find effective diagnostic and therapeutic targets.

AIM OF THE STUDY

To explore the role of homeobox transcript antisense RNA (HOTAIR) in thyroid carcinoma through protein phosphatase methylesterase 1 (PPME1) by sponging microRNA 761 (miR-761).

METHODS

The regulation network amongst HOTAIR, miR-761 and PPME1 was predicted by online sources. RT-PCR was conducted to evaluate the expression of HOTAIR and miR-761 in tumor tissues. Clinical data was collected and analyzed by Chi-square test. Cell apoptosis and proliferation was evaluated using three types of cancer cells (HTh-7, CAL-62, BCPAP) after treated with si-HOTAIR and miR-761inhibitor. The binding site among HOTAIR, miR-761 and PPME1 was verified by dual luciferase reporter assay. PPME1 expression was measured after HOTAIR and miR-761 were suppressed by western blot. Survival time was measured in nude mice using log-rank test.

RESULTS

HOTAIR was expressed to a significantly greater extent than miR-761 in thyroid tumor tissues (P < .001). miR-761 and PPME1 were negatively correlated (coef = -1.91, P < .001). HOTAIR competitively binds to miR-761 and miR-761 directly targets PPME1. HOTAIR was highly correlated with TNM (χ 2 = 5.797, P = .016), tumor size (χ 2 = 7.955, P = .005) and lymphatic metastasis (χ 2 = 6.0, P = .014). HOTAIR promoted cell proliferation and inhibited cell apoptosis, whereas miR-761 did not. HOTAIR elevated and miR-761 suppressed PPME1 expression. HOTAIR expression appears to affect the survival time in vivo.

CONCLUSION

HOTAIR regulated thyroid cancer cells by binding to miR-761 through PPME1.

Teneurins: Role in Cancer and Potential Role as Diagnostic Biomarkers and Targets for Therapy

Teneurins have been identified in vertebrates as four different genes (TENM1-4), coding for membrane proteins that are mainly involved in embryonic and neuronal development. Genetic studies have correlated them with various diseases, including developmental problems, neurological disorders and congenital general anosmia. There is some evidence to suggest their possible involvement in cancer initiation and progression, and drug resistance. Indeed, mutations, chromosomal alterations and the deregulation of teneurins expression have been associated with several tumor types and patient survival. However, the role of teneurins in cancer-related regulatory networks is not fully understood, as both a tumor-suppressor role and pro-tumoral functions have been proposed, depending on tumor histotype. Here, we summarize and discuss the literature data on teneurins expression and their potential role in different tumor types, while highlighting the possibility of using teneurins as novel molecular diagnostic and prognostic biomarkers and as targets for cancer treatments, such as immunotherapy, in some tumors.

Effects and mechanisms of Eps8 on the biological behaviour of malignant tumours (Review)

Epidermal growth factor receptor pathway substrate 8 (Eps8) was initially identified as the substrate for the kinase activity of EGFR, improving the responsiveness of EGF, which is involved in cell mitosis, differentiation and other physiological functions. Numerous studies over the last decade have demonstrated that Eps8 is overexpressed in most ubiquitous malignant tumours and subsequently binds with its receptor to activate multiple signalling pathways. Eps8 not only participates in the regulation of malignant phenotypes, such as tumour proliferation, invasion, metastasis and drug resistance, but is also related to the clinicopathological characteristics and prognosis of patients. Therefore, Eps8 is a potential tumour diagnosis and prognostic biomarker and even a therapeutic target. This review aimed to describe the structural characteristics, role and related molecular mechanism of Eps8 in malignant tumours. In addition, the prospect of Eps8 as a target for cancer therapy is examined.

DNA FISH Diagnostic Assay on Cytological Samples of Thyroid Follicular Neoplasms

Simple Summary

Cytopathology cannot distinguish benign from malignant follicular lesions in 20–30% of cases. These indeterminate cases includes the so-called follicular neoplasms (FNs) according to The Bethesda System for Reporting Thyroid Cytopathology. Frozen samples from 66 classic follicular adenomas (cFAs) and carcinomas (cFTCs) studied by array-comparative genomic hybridization identified three specific alterations of cFTCs (losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X) confirmed by fluorescent in situ hybridization (FISH) in a second independent series of 60 touch preparations from frozen samples of cFAs and cFTCs. In a third independent set of 27 cases of already stained pre-operative fine-needle aspiration cytology samples diagnosed as FNs and histologically verified, FISH analysis using these three markers identified half of cFTCs. Specificity of our assay for identifying cFTCs is higher than 98% which might be comparable with BRAF^600E testing in cases of suspicion of classic papillary thyroid carcinomas.

Abstract

Although fine-needle aspiration cytology (FNAC) is helpful in determining whether thyroid nodules are benign or malignant, this distinction remains a cytological challenge in follicular neoplasms. Identification of genomic alterations in cytological specimens with direct and routine techniques would therefore have great clinical value. A series of 153 cases consisting of 72 and 81 histopathologically confirmed classic follicular adenomas (cFAs) and classic follicular thyroid carcinomas (cFTCs), respectively, was studied by means of different molecular techniques in three different cohorts of patients (pts). In the first cohort (training set) of 66 pts, three specific alterations characterized by array comparative genomic hybridization (aCGH) were exclusively found in half of cFTCs. These structural abnormalities corresponded to losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X. The second independent cohort (validation set) of 60 pts confirmed these data on touch preparations of frozen follicular neoplasms by triple DNA fluorescent in situ hybridization using selected commercially available probes. The third cohort, consisting of 27 archived cytological samples from an equal number of pts that had been obtained for preoperative FNAC and morphologically classified as and histologically verified to be follicular neoplasms, confirmed our previous findings and showed the feasibility of the DNA FISH (DNA fluorescent in situ hybridization) assay. All together, these data suggest that our triple DNA FISH diagnostic assay may detect 50% of cFTCs with a specificity higher than 98% and be useful as a low-cost adjunct to cytomorphology to help further classify follicular neoplasms on already routinely stained cytological specimens.

The expression levels and clinical significance of MFG-E8 and CD133 in epithelial ovarian cancer

The aim of our study was to test whether there is an association between high expression of milk fat globule EGF factor 8 (MFG-E8) and CD133 presence or clinical outcomes of patients with epithelial ovarian cancer (EOC). MFG-E8 and CD133 expression levels were analyzed by immunohistochemistry in 88 EOC tumor specimens. High expression of MFG-E8 directly and significantly correlated with the presence of CD133 immunostaining (R = 0.353, p=.001), whereas immunostaining of MFG-E8 and CD133 significantly correlated with FIGO stage, tumor grade, debulking status, the dualistic model, ascites status, and nonresponse to chemotherapy (p<.05). It was also found that high expression of MFG-E8 and CD133 presence is a potent predictor of poor clinical outcomes among patients with EOC. Our study is the first to show that high expression of MFG-E8 in EOCs positively correlates with CD133 presence. Further research on MFG-E8 in EOC is needed to determine whether MFG-E8 is a new tumor marker of ovarian cancer and a new target for anticancer therapy as well as whether it can interact with cancer stem cell inhibitors for the treatment of refractory tumors.

Comprehensive transcriptomic analysis of papillary thyroid cancer: potential biomarkers associated with tumor progression

PURPOSE

Identification of stage-specific prognostic/predictive biomarkers in papillary thyroid carcinoma (PTC) could lead to its more efficient clinical management. The main objective of this study was to characterize the stage-specific deregulation in genes and miRNA expression in PTC to identify potential prognostic biomarkers.

METHODS

495 RNASeq and 499 miRNASeq PTC samples (stage I-IV) as well as, respectively, 56 and 57 normal samples were retrieved from The Cancer Genome Atlas (TCGA). Differential expression analysis was performed using DESeq 2 to identify deregulation of genes and miRNAs between sequential stages. To identify the minority of patients who progress to higher stages, we performed clustering analysis on stage I RNASeq data. An independent PTC RNASeq data set (BioProject accession PRJEB11591) was also used for the validation of the results.

RESULTS

LTF and PLA2R1 were identified as two promising biomarkers down-regulated in a subgroup of stage I (both in TCGA and in the validation data set) and in the majority of stage IV of PTC (in TCGA data set). hsa-miR-205, hsa-miR-509-2, hsa-miR-514-1 and hsa-miR-514-2 were also detected as up-regulated miRNAs in both PTC patients with stage I and stage III. Hierarchical clustering of stage I samples showed substantial heterogeneity in the expression pattern of PTC indicating the necessity of categorizing stage I patients based on the expressional alterations of specific biomarkers.

CONCLUSION

Stage I PTC patients showed large amount of expressional heterogeneity. Therefore, risk stratification based on the expressional alterations of candidate biomarkers could be an important step toward personalized management of these patients.

Impact of the Tumor Microenvironment on the Gene Expression Profile in Papillary Thyroid Cancer

Transcriptome of papillary thyroid cancer (PTC) is well characterized and correlates with some prognostic and genotypic factors, but data addressing the interaction between PTC and tumor microenvironment (TME) are scarce. Therefore, in the present study, we aimed to assess the impact of TME on gene expression profile in PTC. We evaluated the gene expression profile in PTC and normal thyroid cells isolated by laser capture microdissection and in whole tissue slides corresponding to the entire tumor. We included 26 microdissected samples for gene expression analysis (HG-U133 PLUS 2.0, Affymetrix, currently Thermo Fisher Scientific USA): 15 PTC samples, 11 samples of normal thyrocytes, and 30 whole slides (15 PTC and 15 normal thyroid). Transcripts were divided into three groups: differentially expressed both in microdissected and whole slides, transcripts differently expressed in microdissected samples and not changed in whole slides, and transcripts differentially expressed in whole slides and not changed in microdissected samples. Eleven genes were selected for validation in an independent set of samples; among them, four genes differentiated only microdissected PTC and normal cells. Two genes (PTCSC and CTGF) were confirmed. One gene (FOS) was not confirmed by the validation, whereas EGR1 was also significant in whole slide analysis. The other seven genes (TFF3, FN1, MPPED2, MET, KCNJ2, TACSTD2, and GALE) showed differentiated expression in microdissected thyrocytes and in whole tumor slides. Most of identified genes were related to the tumor-microenvironment interaction and confirmed the crosstalk between TME and cancer cells.

Identification of potential novel biomarkers to differentiate malignant thyroid nodules with cytological indeterminate

Background

The fine-needle aspiration (FNA) biopsy was broadly applied to clinical diagnostics evaluation for thyroid carcinomas nodule, while companioning with higher uncertainty rate (15~30%) to identify malignancy for cytological indeterminate cases. It is requirement to discover novel molecular biomarkers to differentiate malignant thyroid nodule more precise.

Methods

We employed weighted gene co-expression network analysis (WGCNA) to discover genes significantly associated with malignant histopathology for cytological indeterminate nodules. In addition, identified significantly genes were validated through another independently investigations of thyroid carcinomas patient’s samples via cBioportal and Geipa. The key function pathways of significant genes involving were blast through GenClip.

Results

Twenty-four signature genes were identified significantly related to thyroid nodules malignancy. Furthermore, five novel genes with missense mutation, FN1 (R534P), PROS1((K200I), (Q571K)), SCEL (T320S), SLC34A2(T688M) and TENM1 (S1131F), were highlighted as potential biomarkers to rule out nodules malignancy. It was identified that the key functional pathways involving in thyroid carcinomas.

Conclusion

These results will be helpful to better understand the mechanism of thyroid nodules malignant transformation and characterize the potentially biomarkers for thyroid carcinomas early diagnostics.

MetaOmGraph: a workbench for interactive exploratory data analysis of large expression datasets

The diverse and growing omics data in public domains provide researchers with tremendous opportunity to extract hidden, yet undiscovered, knowledge. However, the vast majority of archived data remain unused. Here, we present MetaOmGraph (MOG), a free, open-source, standalone software for exploratory analysis of massive datasets. Researchers, without coding, can interactively visualize and evaluate data in the context of its metadata, honing-in on groups of samples or genes based on attributes such as expression values, statistical associations, metadata terms and ontology annotations. Interaction with data is easy via interactive visualizations such as line charts, box plots, scatter plots, histograms and volcano plots. Statistical analyses include co-expression analysis, differential expression analysis and differential correlation analysis, with significance tests. Researchers can send data subsets to R for additional analyses. Multithreading and indexing enable efficient big data analysis. A researcher can create new MOG projects from any numerical data; or explore an existing MOG project. MOG projects, with history of explorations, can be saved and shared. We illustrate MOG by case studies of large curated datasets from human cancer RNA-Seq, where we identify novel putative biomarker genes in different tumors, and microarray and metabolomics data from Arabidopsis thaliana. MOG executable and code: http://metnetweb.gdcb.iastate.edu/ and https://github.com/urmi-21/MetaOmGraph/.

Network-Based Genetic Profiling Reveals Cellular Pathway Differences Between Follicular Thyroid Carcinoma and Follicular Thyroid Adenoma

Molecular mechanisms underlying the pathogenesis and progression of malignant thyroid cancers, such as follicular thyroid carcinomas (FTCs), and how these differ from benign thyroid lesions, are poorly understood. In this study, we employed network-based integrative analyses of FTC and benign follicular thyroid adenoma (FTA) lesion transcriptomes to identify key genes and pathways that differ between them. We first analysed a microarray gene expression dataset (Gene Expression Omnibus GSE82208, n = 52) obtained from FTC and FTA tissues to identify differentially expressed genes (DEGs). Pathway analyses of these DEGs were then performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) resources to identify potentially important pathways, and protein-protein interactions (PPIs) were examined to identify pathway hub genes. Our data analysis identified 598 DEGs, 133 genes with higher and 465 genes with lower expression in FTCs. We identified four significant pathways (one carbon pool by folate, p53 signalling, progesterone-mediated oocyte maturation signalling, and cell cycle pathways) connected to DEGs with high FTC expression; eight pathways were connected to DEGs with lower relative FTC expression. Ten GO groups were significantly connected with FTC-high expression DEGs and 80 with low-FTC expression DEGs. PPI analysis then identified 12 potential hub genes based on degree and betweenness centrality; namely, TOP2A, JUN, EGFR, CDK1, FOS, CDKN3, EZH2, TYMS, PBK, CDH1, UBE2C, and CCNB2. Moreover, transcription factors (TFs) were identified that may underlie gene expression differences observed between FTC and FTA, including FOXC1, GATA2, YY1, FOXL1, E2F1, NFIC, SRF, TFAP2A, HINFP, and CREB1. We also identified microRNA (miRNAs) that may also affect transcript levels of DEGs; these included hsa-mir-335-5p, -26b-5p, -124-3p, -16-5p, -192-5p, -1-3p, -17-5p, -92a-3p, -215-5p, and -20a-5p. Thus, our study identified DEGs, molecular pathways, TFs, and miRNAs that reflect molecular mechanisms that differ between FTC and benign FTA. Given the general similarities of these lesions and common tissue origin, some of these differences may reflect malignant progression potential, and include useful candidate biomarkers for FTC and identifying factors important for FTC pathogenesis.

Targeting Non-Oncogene Addiction: Focus on Thyroid Cancer

Thyroid carcinoma (TC) is the most common malignancy of endocrine organs with an increasing incidence in industrialized countries. The majority of TC are characterized by a good prognosis, even though cases with aggressive forms not cured by standard therapies are also present. Moreover, target therapies have led to low rates of partial response and prompted the emergence of resistance, indicating that new therapies are needed. In this review, we summarize current literature about the non-oncogene addiction (NOA) concept, which indicates that cancer cells, at variance with normal cells, rely on the activity of genes, usually not mutated or aberrantly expressed, essential for coping with the transformed phenotype. We highlight the potential of non-oncogenes as a point of intervention for cancer therapy in general, and present evidence for new putative non-oncogenes that are essential for TC survival and that may constitute attractive new therapeutic targets.

BCL2 and hsa-miR-181a-5p are potential biomarkers associated with papillary thyroid cancer based on bioinformatics analysis

Background

The morbidity of thyroid carcinoma has been rising worldwide and increasing faster than any other cancer type. The most common subtype with the best prognosis is papillary thyroid cancer (PTC); however, the exact molecular pathogenesis of PTC is still not completely understood.

Methods

In the current study, 3 gene expression datasets (GSE3678, GSE3467, and GSE33630) and 2 miRNA expression datasets (GSE113629 and GSE73182) of PTC were selected from the Gene Expression Omnibus (GEO) database and were further used to identify differentially expressed genes (DEGs) and deregulated miRNAs between normal thyroid tissue samples and PTC samples. Then, Gene Ontology (GO) and pathway enrichment analyses were conducted, and a protein-protein interaction (PPI) network was constructed to explore the potential mechanism of PTC carcinogenesis. The hub gene detection was performed using the CentiScaPe v2.0 plugin, and significant modules were discovered using the MCODE plugin for Cytoscape. In addition, a miRNA-gene regulatory network in PTC was constructed using common deregulated miRNAs and DEGs.

Results

A total of 263 common DEGs and 12 common deregulated miRNAs were identified. Then, 6 significant KEGG pathways (P < 0.05) and 82 significant GO terms were found to be enriched, indicating that PTC was closely related to amino acid metabolism, development, immune system, and endocrine system. In addition, by constructing a PPI network and miRNA-gene regulatory network, we found that hsa-miR-181a-5p regulated the most DEGs, while BCL2 was targeted by the most miRNAs.

Conclusions

The results of this study suggested that hsa-miR-181a-5p and BCL2 and their regulatory networks may play important roles in the pathogenesis of PTC.

Heterogenous nature of gene expression patterns in BRAF-like papillary thyroid carcinomas with BRAFV600E

PURPOSE

Papillary thyroid cancers (PTCs) are the most common type of thyroid cancers, in which BRAF^V600E is the most prevalent driver mutation. It is known that BRAF^V600E-positive PTCs are clinically and molecularly heterogenous in terms of aggressiveness and prognosis. The molecular mechanisms of this heterogeneity were evaluated.

METHODS

The publicly available RNA-seq data for 26 classical (c) and 5 follicular variant (fv) PTCs with BRAF^V600E mutation and the BRAF-like expression signature in the BRAF^V600E-RAS score (BRS) and their respective normal adjacent tissues were downloaded, and analyzed for differentially expressed genes (DEGs). The DEGs were then analyzed with the Gene Ontology annotation and the KEGG pathway dataset.

RESULTS

We found four lines of evidence for heterogeneity of cPTCs. First, the cluster dendrogram and principle component analyses could not completely distinguish the cancer tissues from normal tissues. Second, the DEGs identified in each sample were highly diverse from one another. Third, although the DEGs were enriched in many terms containing the word "extracellular" ("extracellular region", "extracellular space", and so on) when analyzed as groups, the degree of this enrichment was variable when analyzed individually. Fourth, there are only a few intersections in the over-/underexpressed genes annotated with the terms containing the word "extracellular" among the samples examined. Essentially same results were obtained with BRAF-like, fvPTCs with BRAF^V600E. Nevertheless, some frequently over-/underexpressed genes were detected, of which LIPH (lipase H) expression was found to be prognostic and its high expression was favorable for PTCs.

CONCLUSION

Groups of BRAF-like, BRAF^V600E-positive cPTCs and fvPTCs that are homogenous in regard to histopathology, driver mutation and BRS were found to be highly heterogenous in terms of gene expression patterns. Yet, among the genes that were annotated with the terms containing the word "extracellular" and frequently over-/underexpressed, LIPH is a favorable prognostic marker for PTCs.

microRNA-mediated GAS1 downregulation promotes the proliferation of synovial fibroblasts by PI3K-Akt signaling in osteoarthritis

Hyperplastic synovial fibroblasts (SFs) serve a critical role in the pathogenesis of knee osteoarthritis (OA); however, the molecular mechanism involved in OA during synovial tissue hyperproliferation remains unclear. Growth arrest-specific gene 1 (GAS1), a cell growth repressor gene, was found to be downregulated in OASFs according to previous preliminary experiments. It was therefore hypothesized that reduced GAS1 expression may participate in the hyperproliferation of SFs in OA development, downstream of possible microRNA (miR) regulation, in hyperplastic OASFs. In the present study, GAS1 expression was indeed decreased in OASFs and interleukin-1β-induced SFs by reverse transcription-quantitative PCR and western blot analysis. Further cell viability assays, cell cycle and apoptosis analyses revealed that the overexpression of GAS1 can inhibited proliferation, induced cell cycle arrest and promoted apoptosis in SFs. In contrast, GAS1 knockdown in SFs accelerated cell proliferation, enhanced cell cycle progression and suppressed apoptosis. Notably, the suppressive effects of GAS1 were mediated through the inactivation of the PI3K-Akt pathway. Finally, miR-34a-5p and miR-181a-5p were predicted and subsequently verified to directly target the 3′-untranslated region of the GAS1 gene, downregulating GAS1 levels in OASFs and IL-1β-induced SFs. In conclusion, the present study demonstrated that downregulation of GAS1 can lead to the hyperproliferation of SFs in OA pathogenesis through the PI3K-Akt pathway, and miR-34a-5p and miR-181a-5p are potential regulators of GAS1 expression in OA. Therefore, it may be promising to investigate the potential of GAS1 as a novel therapeutic target for preventing SF hyperplasia in OA.

CITED1 contributes to the progression of papillary thyroid carcinoma via the Wnt/β-catenin signaling pathway

Purpose

The incidence rate of thyroid cancer, the most common endocrine malignancy, has increased rapidly over the past 10 years. However, the fundamental molecular mechanisms underlying the malignant progression of thyroid cancer are unclear.

Materials and methods

Firstly, quantitative real-time PCR analysis and Western blot analysis were used to investigate the expression of Cbp/p300 interacting transactivator with Glu/Asp rich carboxy-terminal domain 1 (CITED1) in papillary thyroid carcinoma (PTC) cell lines. Then, we investigated the effects of CITED1 knockdown on cell proliferation, apoptosis, and invasion in in vitro and in vivo models of PTC.

Results

CITED1 was upregulated in PTC cell lines, and CITED1 knockdown significantly suppressed the proliferation, migration, and invasion of K1 cells resulting in a G0/G1 phase block. Furthermore, the silencing of CITED1 significantly promoted cell apoptosis. In the in vivo study, the growth speed and weight of the transplanted tumor were significantly suppressed in nude mice infected with short hairpin RNA targeting CITED1 (CITE1-shRNA) cells. Furthermore, we found that CITED1-shRNA activated Wnt/β-catenin signaling in PTC.

Conclusion

Taken together, our findings suggest that CITED1 knockdown facilitates apoptosis and inhibits proliferation and invasion in K1 cells via the Wnt/β-catenin signaling pathway.

Microarray-based differential expression profiling of long noncoding RNAs and messenger RNAs in formalin-fixed paraffin-embedded human papillary thyroid carcinoma samples

BACKGROUND

Long noncoding RNAs (lncRNAs) can regulate the expression of genes at almost every level. The altered expression of lncRNAs was observed in many kinds of cancers. Until recently, few studies have focused on the function of lncRNAs in the context of papillary thyroid carcinoma (PTC).

METHODS

In the current study, we collected seven PTC and nodular goiter tissue samples and explored mRNA and lncRNA expression patterns in these samples by microarray.

RESULTS

We observed aberrant expression of 94 lncRNAs and 99 mRNAs in the seven PTC samples as compared to the nodular goiter tissue [fold change (FC) ≥2.0; P<0.01]. To confirm these microarray results, quantitative polymerase chain reaction (q-PCR) was performed to assess the expression of three randomly selected differentially expressed mRNAs and lncRNAs, confirming our microarray findings significantly. We then performed gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses to systematically characterize the twelve significantly differential genes. A co-expression analysis revealed that the lncRNAs n382996, n342483, and n409114 were closely related to the regulation of MT1G, MT1H, and MT1F.

CONCLUSIONS

In the present study a string of novel lncRNAs associated with PTC were identified. Further study of these lncRNAs should be performed to identify novel target molecules which may improve diagnosis and treatment of PTC.

Papillary Thyroid Cancer: Genetic Alterations and Molecular Biomarker Investigations

Papillary thyroid cancer (PTC) is the most prevalent form of malignancy among all cancers of the thyroid. It is also one of the few cancers with a rapidly increasing incidence. PTC is usually contained within the thyroid gland and generally biologically indolent. Prognosis of the cancer is excellent, with less than 2% mortality at 5 years. However, more than 25% of patients with PTC developed a recurrence during a long term follow-up. The present article provides an updated condensed overview of PTC, which focuses mainly on the molecular alterations involved and recent biomarker investigations.

Long noncoding RNA cancer susceptibility candidate 2 suppresses papillary thyroid carcinoma growth by inactivating the AKT/ERK1/2 signaling pathway

OBJECTIVES

Cancer susceptibility candidate 2 (CASC2) and long noncoding RNA (lncRNA) have been identified as a tumor suppressor in colorectal, lung, renal, and stomach cancer as well as in patient gliomas, but the function of CASC2 in papillary thyroid carcinoma (PTC) is not yet clear. The present study aimed to explore the effects of CASC2 in PTC.

METHODS

The CASC2 expression was measured in PTC samples and normal tissues by using quantitative real-time polymerase chain reaction. The lentiviral vectors were used to establish CASC2 overexpression models in PTC cell lines to determine the effects of CASC2 on cell proliferation, apoptosis, migration, and invasion. A tumor xenograft animal model was used to examine the functions of overexpression CASC2.

RESULTS

CASC2 expression was significantly decreased in PTC tumor tissues than adjacent normal tissues. CASC2 downregulation in PTC tissues significantly correlated with the tumor size, the presence of multifocal lesions, and the advanced pathological stage. CASC2 overexpression suppressed the cell proliferation and promoted apoptosis in PTC cell lines and CASC2 overexpression resulted in the inactivation of protein kinase B (PKB/AKT) and extracellular signal-regulated kinases (ERK1/2). The regulatory effects of CASC2 on PTC cell biological behavior were further enhanced by mitogen-activated protein kinase kinase (MEK) inhibitor U0126 or AKT1/2/3 inhibitor MK-2206 2HCl. CASC2 overexpression suppressed tumor growth in PTC cells in xenograft mouse models.

CONCLUSION

Our results indicated that CASC2 significantly suppressed tumorigenesis in PTC and CASC2 may serve as a novel prognostic marker or therapeutic target.

Current concepts and challenges to unravel the role of iodothyronine deiodinases in human neoplasias

Thyroid hormones (THs) are essential for the regulation of several metabolic processes and the energy consumption of the organism. Their action is exerted primarily through interaction with nuclear receptors controlling the transcription of thyroid hormone-responsive genes. Proper regulation of TH levels in different tissues is extremely important for the equilibrium between normal cellular proliferation and differentiation. The iodothyronine deiodinases types 1, 2 and 3 are key enzymes that perform activation and inactivation of THs, thus controlling TH homeostasis in a cell-specific manner. As THs seem to exert their effects in all hallmarks of the neoplastic process, dysregulation of deiodinases in the tumoral context can be critical to the neoplastic development. Here, we aim at reviewing the deiodinases expression in different neoplasias and exploit the mechanisms by which they play an essential role in human carcinogenesis. TH modulation by deiodinases and other classical pathways may represent important targets with the potential to oppose the neoplastic process.

CITED1 promotes proliferation of papillary thyroid cancer cells via the regulation of p21 and p27

Background

It has been reported that CBP/p300-Interacting Transactivator with glutamic acid [E]/aspartic acid [D]-rich C-terminal domain 1 (CITED1) is overexpressed in papillary thyroid cancer (PTC). However, the functional significance and underlying mechanisms of CITED1 in PTC are largely unknown.

Methods

The Cancer Genome Atlas dataset and real-time PCR were used to determine the expression of CITED1 in PTC. The role of CITED1 in PTC cell proliferation was determined conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, and flow cytometry assays in vitro, and a subcutaneous xenotransplantation tumor model in nude mice was established to analyze tumor growth in vivo. We studied the potential mechanisms underlying the contribution of CITED1 to PTC proliferation using western blotting and luciferase assays.

Results

We found that CITED1 was highly expressed in PTC. In vitro and in vivo experiments demonstrated that CITED1 was involved in PTC cell proliferation and tumorigenesis. Then, gain- and loss-of-function experiments revealed that CITED1 decreased the expression of p21 and p27, and thereby increased the phosphorylation of pRb as well as E2F1 transcriptional activity.

Conclusions

Our results suggest that CITED1 is overexpressed in PTC and that CITED1 promotes the proliferation of PTC cells via the regulation of p21 and p27, which indicates that CITED1 might be a potential therapeutic target in the treatment of PTC.

Epigenetic chromatin conformation changes in peripheral blood can detect thyroid cancer

BACKGROUND

Fine needle aspiration has been the traditional method for diagnosing thyroid cancer. Epigenetic chromatin conformation changes offer an alternative method of diagnosing cancer. The purpose of this study is to evaluate an EpiSwitch assay of epigenetic markers that can be used to diagnose thyroid cancer in blood samples.

METHODS

From 2014 to 2016, adult patients with thyroid nodules having thyroidectomy were recruited and grouped based on benign, malignant, and atypia of undetermined significance or follicular lesions of undetermined significance fine needle aspiration cytology. Blood samples were collected before surgery. Final pathologic diagnosis was made from the thyroid specimens. Patients' blood samples were analyzed using the EpiSwitch assay, (Oxford Biodynamics, Oxford, UK), and the results were compared with surgical pathology to determine assay performance.

RESULTS

In total, 58 patients were recruited: 20 benign, 20 malignant, and 18 atypia or follicular lesions of undetermined significance. An analysis of the malignant and benign fine needle aspiration groups found 6 epigenetic markers for thyroid. A total of 28 (48%) patients had thyroid cancer. The assay was able to correctly identify 25 of the 28 malignant nodules, showing sensitivity of 89.3% and specificity of 66.7%. The positive predictive value for the assay was 71.4%, whereas the negative predictive value was 87.0%.

CONCLUSION

An epigenetic assay of peripheral blood shows high sensitivity in detecting thyroid cancer and provides an additional method for its diagnosis.

Single Nucleotide Polymorphism in SMAD7 and CHI3L1 and Colorectal Cancer Risk

Colorectal cancer (CRC) is one of the leading cancers throughout the world. It represents the third most common cancer and the fourth in mortality. Most of CRC are sporadic, arise with no known high-penetrant genetic variation and with no previous family history. The etiology of sporadic CRC is considered to be multifactorial and arises from the interaction of genetic variants of low-penetrant genes and environmental risk factors. The most common well-studied genetic variation is single nucleotide polymorphisms (SNPs). SNP arises as a point mutation. If the frequency of the sequence variation reaches 1% or more in the population, it is referred to as polymorphism, but if it is lower than 1%, the allele is typically considered as a mutation. Lots of SNPs have been associated with CRC development and progression, for example, genes of TGF-β1 and CHI3L1 pathways. TGF-β1 is a pleiotropic cytokine with a dual role in cancer development and progression. TGF-β1 mediates its actions through canonical and noncanonical pathways. The most important negative regulatory protein for TGF-β1 activity is termed SMAD7. The production of TGF-β can be controlled by another protein called YKL-40. YKL-40 is a glycoprotein with an important role in cancer initiation and metastasis. YKL-40 is encoded by the CHI3L1 gene. The aim of the present review is to give a brief introduction of CRC, SNP, and examples of some SNPs that have been documented to be associated with CRC. We also discuss two important signaling pathways TGF-β1 and CHI3L1 that influence the incidence and progression of CRC.

CITED1 gene promotes proliferation, migration and invasion in papillary thyroid cancer

Thyroid cancer is the most common malignancy of the endocrine organs. In order to further understand the tumorigenesis and progression of papillary thyroid carcinoma (PTC), the present study performed whole transcriptome sequence analysis. It was found that Cbp/p300-interacting transactivators with glutamic acid [E] and aspartic acid [D]-rich C-terminal domain 1 (CITED1) was a novel potential PTC-associated gene in thyroid cancer. The expression level and clinicopathological features of CITED1 were then assessed in The Cancer Genome Atlas (TCGA) database. The expression of CITED1 was knocked down and the biological function of CITED1 in PTC cell lines was examined. The results showed that upregulated CITED1 was associated with lymph node metastasis (P=0.006) and clinical stage (P=0.003). In order to differentiate PTC tissues and normal tissues, an area under the curve was constructed of a receiver operating characteristic of 91.3% for the TCGA cohort and 85.3% for a validated cohort. The downregulated expression of CITED1 significantly inhibited cell proliferation, colony formation, migration and invasion in the PTC cell lines. The present study demonstrated that CITED1 is important in the tumorigenesis and metastasis of PTC and may be a potential therapeutic target in PTC.

The Molecular Basis of Thyroid Epithelial Tumorigenesis

Significant alterations in gene sequences, expression levels and protein structures have been associated with specific types of thyroid epithelial tumorigenesis. Recent revolutionary changes in molecular biology have spanned the disciplines of genomics and proteomics, which systematically generate and analyze the information about genomes, gene transcripts, proteins and their functions in a global, comprehensive manner. The application of these approaches will better discriminate between thyroid tumor subtypes that are not recognizable when traditional pathological criteria are used.

Expression of serum AMPD1 in thyroid carcinoma and its clinical significance

This study investigated the expression of adenosine monophosphate deaminase 1 (AMPD1) in serum of patients with papillary thyroid carcinoma (PTC) and its clinical significance. The expression levels of AMPD1 mRNA in serum of 157 patients with PTC and 100 normal controls were detected by real-time fluorescent quantitative polymerase chain reaction (PCR), and the relationships between expression level of AMPD1 in serum of PTC patients and clinicopathological factors as well as prognosis were analyzed. The results of real-time fluorescent quantitative PCR showed that the expression of AMPD1 mRNA in serum of PTC patients was lower than that in normal human serum (P<0.01). The expression of AMPD1 in serum of PTC patients was not significantly different from the clinicopathological features such as sex, age, lymph node metastasis and the number of lesions (P>0.05); there were distinct differences between its expression and tumor-node-metastasis (TNM) staging and tumor diameter (P<0.05). The single factor Cox analysis revealed that sex, age, number of lesions, TNM staging and the occurrence of lymph node metastasis were significantly correlated with the prognosis of patients (P<0.05). Multivariate Cox analysis showed that TNM staging hazard ratio (HR)=2.93, 95% confidence interval (CI): 1.52-7.04, P=0.015 was an independent prognostic factor in PTC patients. Survival analysis indicated that there was a statistically significant difference in the 5-year overall survival rate between patients with high expression of AMPD1 and those with low expression (P=0.007). In conclusion, the expression of AMPD1 in serum of patients with PTC is closely related to the malignant evolution of PTC and clinical prognosis of patients. AMPD1 is expected to become an important molecule in judging the clinical prognosis of PTC patients, and may become a new target for molecular targeted therapy of PTC.

Extracellular ATP is Differentially Metabolized on Papillary Thyroid Carcinoma Cells Surface in Comparison to Normal Cells

The incidence of differentiated thyroid cancer has been increasing. Nevertheless, its molecular mechanisms are not well understood. In recent years, extracellular nucleotides and nucleosides have emerged as important modulators of tumor microenvironment. Extracellular ATP is mainly hydrolyzed by NTPDase1/CD39 and NTPDase2/CD39L1, generating AMP, which is hydrolyzed by ecto-5'-nucleotidase (CD73) to adenosine, a possible promoter of tumor growth and metastasis. There are no studies evaluating the expression and functionality of these ectonucleotidases on normal or tumor-derived thyroid cells. Thus, we investigated the ability of thyroid cancer cells to hydrolyze extracellular ATP generating adenosine, and the expression of ecto-enzymes, as compared to normal cells. We found that normal thyroid derived cells presented a higher ability to hydrolyze ATP and higher mRNA levels for ENTDP1-2, when compared to papillary thyroid carcinoma (PTC) derived cells, which had a higher ability to hydrolyze AMP and expressed CD73 mRNA and protein at higher levels. In addition, adenosine induced an increase in proliferation and migration in PTC derived cells, whose effect was blocked by APCP, a non-hydrolysable ADP analogue, which is an inhibitor of CD73. Taken together, these results showed that thyroid follicular cells have a functional purinergic signaling. The higher expression of CD73 in PTC derived cells might favor the accumulation of extracellular adenosine in the tumor microenvironment, which could promote tumor progression. Therefore, as already shown for other tumors, the purinergic signaling should be considered a potential target for thyroid cancer management and treatment.

Integrated analysis of fine-needle-aspiration cystic fluid proteome, cancer cell secretome, and public transcriptome datasets for papillary thyroid cancer biomarker discovery

Thyroid ultrasound and ultrasound-guided fine-needle aspiration (USG/FNA) biopsy are currently used for diagnosing papillary thyroid carcinoma (PTC), but their detection limit could be improved by combining other biomarkers. To discover novel PTC biomarkers, we herein applied a GeLC-MS/MS strategy to analyze the proteome profiles of serum-abundant-protein-depleted FNA cystic fluid from benign and PTC patients, as well as two PTC cell line secretomes. From them, we identified 346, 488, and 2105 proteins, respectively. Comparative analysis revealed that 191 proteins were detected in the PTC but not the benign cystic fluid samples, and thus may represent potential PTC biomarkers. Among these proteins, 101 were detected in the PTC cell line secretomes, and seven of them (NPC2, CTSC, AGRN, GPNMB, DPP4, ERAP2, and SH3BGRL3) were reported in public PTC transcriptome datasets as having 4681 elevated mRNA expression in PTC. Immunoblot analysis confirmed the elevated expression levels of five proteins (NPC2, CTSC, GPNMB, DPP4, and ERAP2) in PTC versus benign cystic fluids. Immunohistochemical studies from near 100 pairs of PTC tissue and their adjacent non-tumor counterparts further showed that AGRN (n = 98), CTSC (n = 99), ERAP2 (n = 98) and GPNMB (n = 100) were significantly (p < 0.05) overexpressed in PTC and higher expression levels of AGRN and CTSC were also significantly associated with metastasis and poor prognosis of PTC patients. Collectively, our results indicate that an integrated analysis of FNA cystic fluid proteome, cancer cell secretome and tissue transcriptome datasets represents a useful strategy for efficiently discovering novel PTC biomarker candidates.

A six-gene panel to label follicular adenoma, low- and high-risk follicular thyroid carcinoma

The distinction between follicular thyroid carcinomas (FTCs) and follicular-patterned benign lesions is almost impossible on fine-needle aspiration cytology. Furthermore, minimally invasive FTCs (MI-FTCs) with less than 4 vascular invasion foci generally have an excellent prognosis, but there are exceptions and, so far, no molecular marker appears able to identify them reliably. We aimed to distinguish benign lesions from low- and high-risk FTCs by a small-scale combination of genes. The expression analysis of 75 selected genes was performed on 18 follicular adenomas (FAs), 14 MI-FTCs and 6 widely invasive FTC (WI-FTCs). The mutational status of the RAS genes, TERT promoter and PAX8-PPARG rearrangements was also investigated. Seven samples were mutated, namely 3 MI-FTCs and 4 WI-FTCs. Twenty-five genes were differentially expressed (FDR <0.05) between FAs and WI-FTCs. Six of these (ECM1, RXRG, SDPR, SLC26A4, TIFF3, TIMP1) were also differently expressed among MI-FTCs and FAs or WI-FTCs and were considered to build a classification model, which was tested to classify samples according to their histological class. Hence, 31 out of 38 were correctly classified, and accuracy remained high after cross-validation (27/38). The 2 MI-FTCs incorrectly classified as WI-FTCs harbored both RAS and TERT promoter mutations. The capability of these six genes to stratify benign, low- and high-risk lesions appears to be promising in supporting the diagnosis of indeterminate thyroid nodules.

Overexpression of teneurin transmembrane protein 1 is a potential marker of disease progression in papillary thyroid carcinoma

Although papillary thyroid cancer is a relatively indolent malignancy, its progression may be associated with dedifferentiation and resistance to radioactive iodine treatment. In this study, patterns of differentially expressed genes in association with disease progression were systemically evaluated. We firstly performed transcriptome analyses for four matched cancerous and noncancerous tissue pairs of the classical subtype of papillary thyroid cancer. Among the upregulated and downregulated genes, the expression of 164 and 183 genes increased and decreased, respectively, from stage I to stage IV. Functional enrichment and pathway analysis showed that angiogenesis pathway was upregulated, whereas oxidation-reduction and metabolism of reactive oxygen species were downregulated. Teneurin transmembrane protein 1 (TENM1) expression was highly upregulated in cancerous tissues and negative in benign thyroid tissues. By immunohistochemistry, TENM1 expression in papillary thyroid cancer was associated with the classical subtype (p = 0.018), extrathyroidal invasion (p = 0.001), BRAF V600E mutation (p < 0.001), and an advanced stage (p = 0.019). Taken together, our results indicate that distinct pathways are involved in papillary thyroid cancer progression, and TENM1 is a potential marker of cancer progression.

Prognostic Correlation Between MFG-E8 Expression Level and Colorectal Cancer

BACKGROUND AND AIMS

Colorectal cancer (CRC) is one of the leading causes of cancer-related death all over the world. Milk fat globule-epidermal growth factor (EGF)-factor VIII (MFG-E8) was found to be highly expressed in a variety of cancers. However its role in CRC is unclear. This study investigates the expression of MFG-E8 in CRC tissues and the correlation with clinicopathological features and prognosis in CRC patients.

METHODS

The expression of MFG-E8 proteins was detected by immunohistochemical staining in 90 samples of CRC. The localization of MFG-E8 in colorectal tumor was examined by immunofluorescence staining. The correlation between MFG-E8 protein expression and the clinical pathological features of CRC were evaluated by χ² test and Fisher's exact test. The survival rates were analyzed by the Kaplan-Meier method, and the relationship between prognostic factors and patient survival was analyzed by the Cox proportional hazard models.

RESULTS

Our results showed that MFG-E8 expression increased significantly in colorectal cancer compared with normal mucosa tissues (p <0.001). We further validated MFG-E8 overexpression in 6 pairs of fresh tumor and adjacent normal mucosa tissues from colorectal cancer patients by Western blot (p <0.05). Immunofluorescence staining showed that MFG-E8 accumulated in close proximity to endothelial cells in human colorectal tumor tissue. In addition, high MFG-E8 protein expression was correlated with lymph node metastasis and some pathological classifications (p <0.05). Furthermore, patients with high protein level of MFG-E8 showed shortened overall survivals (p <0.05).

CONCLUSION

Our results showed that MFG-E8 could be a potential novel prognostic marker for CRC and overexpression of MFG-E8 might be involved in lymph node metastasis and angiogenesis of CRC.

Identification of Two Distinct Molecular Subtypes of Non-Invasive Follicular Neoplasm with Papillary-Like Nuclear Features by Digital RNA Counting

BACKGROUND

The follicular variant (FV) of papillary thyroid cancer (PTC) is one of the most common variants of PTC. Clinically, non-infiltrative FVPTC is considered a low-risk variant of PTC, and the non-invasive encapsulated forms of FVPTC represent a group of thyroid tumors with a particularly good prognosis. Consequently, these neoplasms have been very recently reclassified as non-invasive follicular neoplasms with papillary-like nuclear features (NIFTP). From a molecular standpoint, NIFTP appears to be similar to follicular neoplasms. However, only limited data are currently available regarding their gene expression profile.

METHODS

The aim of this study was to identify specific molecular signatures of 26 NIFTPs compared to those of 19 follicular adenomas (FAs) and 18 infiltrative FVPTCs (IFVPTCs). A nanoString custom assay was used to perform mRNA expression analysis. All cases were also genotyped for BRAF, N-, H-, and K-RAS mutations. Samples were grouped on the basis of gene expression profiles by Pearson's correlation and non-negative matrix factorization clustering analysis. Finally, the uncorrelated shrunken centroid machine-learning algorithm was used to classify the samples.

RESULTS

The results revealed distinct expression profiles of FAs and IFVPTCs. NIFTP samples can exhibit different expression profiles, more similar to FAs (FA-like) or to IFVPTCs (IFVPTC-like), and these different expression profiles largely depend on the presence of different mutations (RAS or BRAF).

CONCLUSION

In conclusion, although further validation of the model is required by using a larger group of prospective cases, these data reinforce the hypothesis that IFVPTC-like NIFTPs might represent precursors of IFVPTC.