Familial Papillary Thyroid Cancer Research Articles

Clinical relevance and outcome of familial papillary thyroid cancer: a single institution study of 626 familial cases.

Whether familial thyroid cancer is more aggressive than sporadic thyroid cancer remains controversial. Additionally, whether the number of affected family members affects the prognosis is unknown. This study focused mainly on the comparison of the clinicopathological characteristics and prognoses between papillary thyroid cancer (PTC) patients with and without family history. A total of 626 familial papillary thyroid cancer (FPTC) and 1252 sporadic papillary thyroid cancer (SPTC) patients were included in our study. The clinical information associated with FPTC and SPTC was recorded and analyzed by univariate analysis. Patients in the FPTC group had a higher rate of multifocality (p=0.001), bilaterality (p=0.000), extrathyroidal invasion (p=0.000), distant metastasis (p=0.012), lymph node metastasis (p=0.000), recurrence (p=0.000), a larger tumor size (p=0.000) and more malignant lymph nodes involved (central: p=0.000; lateral: p=0.000). In addition, our subgroup analysis showed no significant difference (p>0.05) between patients with only one affected family member and those with two of more group in all clinicopathological characteristics. In papillary thyroid microcarcinoma (PTMC) subgroup analysis, we found that FPTMC patients harbored significantly larger tumors (p=0.000), higher rates of multifocality (p=0.014), bilaterality (p=0.000), distant metastasis (p=0.038), lymph node metastasis (p=0.003), greater numbers of malignant lymph nodes (central: p=0.002; lateral: p=0.044), higher rates of I-131 treatment (p=0.000) and recurrence (p=0.000) than SPTMC patients. Our results indicated that PTC and PTMC patients with a positive family history had more aggressive clinicopathological behaviors, suggesting that more vigilant screening and management for FPTC may be helpful.

PSAT384 Familial Non-Medullary Thyroid Cancer — Does The Number Of Alanine Residues In The FOXE1 Gene Play A Role?

Abstract Familial non-medullary thyroid cancer (FNMTC) constitutes about 3–9% of all thyroid cancers. One of the genes believed to predispose to non-syndromic FNMTC is FOXE1. It contains a polyalanine tract (polyAla) with a variable number (11–22) of alanine residues. This length polymorphism could lead to changes in the FOXE1-encoded protein (FOXE1 transcription factor) structure and predispose to papillary thyroid cancer (PTC). The aim of the study was to investigate the relationship between the length of the polyAla tract and the stage of PTC at diagnosis (according to AJCC 8th edition) in patients with FNMTC. The study included 27 patients (from twenty families) with familial PTC (at least two family members were diagnosed with the disease). The length of the polyAla tract of the FOXE1 gene was analyzed. The following numbers of polyAla variants were detected: 11-Ala – 2, 12-Ala – 1, 14-Ala – 23, 16-Ala – 28 alleles. The staging at diagnosis was compared in two groups: less than 16-Ala and at least 16-Ala. The stages of pT1a and pT1a (m) were found in 20 alleles in the less than 16-Ala group, whereas in 16 alleles of the at least 16-Ala group, pT1b-pT2(m) was the most common (p = 0.039). Lymph node metastases were found more frequently in the less than 16-Ala group than in the at least 16-Ala group but this difference was not statistically significant (10 vs. 3 respectively; p = 0.680). Conclusions The analysis of the length of the polyAla tract may be a useful diagnostic tool in predicting the course of PTC in patients with a positive family history. The research was funded by the Jagiellonian University Medical College grant No N41/DBS/000087. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Cathepsin F genetic mutation is associated with familial papillary thyroid cancer

BackgroundThyroid cancer is one of the most common cancers in the world. Genetic factors are important in the occurrence and development of thyroid cancer, and genetic diagnosis has become an important basis for the prognosis of benign and malignant nodules. We identify a family of six siblings with inherited thyroid cancer susceptibility. All six members of this generation have been definitely diagnosed with papillary thyroid carcinoma. This work aims at confirming the relevant causative genes for thyroid cancer in this pedigree. MethodsWe extract DNA from the peripheral blood of six individuals and perform whole genome sequencing. Sanger sequencing and immunohistochemistry further testify the cathepsin F (CTSF) mutation and expression. ResultsWe identify 57 single nucleotide variations (SNVs) out of at least 4 affected family members via certain filter criteria. The CTSF gene found in five of the six family members is here considered the most promising candidate gene mutation for familial thyroid cancer. Besides, our research also proves several known genes including CTSB, TEKT4, ESR1, MSH6, DIRC3, GNAS, and BANCR that act as probable oncogenic drivers in this family. The Sanger sequencing identifies the existence and veracity of CTSF somatic mutations. The CTSF immunohistochemistry of thyroid cancer tissue specimens displays that higher CTSF expression in mutated patients than that in wild-type patient as well as pericarcinomatous tissue. ConclusionsWe conclude that the evaluation of CTSF gene mutations of patients in thyroid cancer families may be predictive and valuable for the familial heredity of thyroid cancer.

Germ-line mutations in WDR77 predispose to familial papillary thyroid cancer

The inheritance of predisposition to nonsyndromic familial nonmedullary thyroid cancer (FNMTC) remains unclear. Here, we report six individuals with papillary thyroid cancer (PTC) in two unrelated nonsyndromic FNMTC families. Whole-exome sequencing revealed two germ-line loss-of-function variants occurring within a 28-bp fragment of WDR77, which encodes a core member of a transmethylase complex formed with the protein arginine methyltransferase PRMT5 that is responsible for histone H4 arginine 3 dimethylation (H4R3me2) in frogs and mammals. To date, the association of WDR77 with susceptibility to cancer in humans is unknown. A very rare heterozygous missense mutation (R198H) in WDR77 exon 6 was identified in one family of three affected siblings. A heterozygous splice-site mutation (c.619+1G > C) at the 5' end of intron 6 is present in three affected members from another family. The R198H variant impairs the interaction of WDR77 with PRMT5, and the splice-site mutation causes exon 6 skipping and results in a marked decrease in mutant messenger RNA, accompanied by obviously reduced H4R3me2 levels in mutation carriers. Knockdown of WDR77 results in increased growth of thyroid cancer cells. Whole-transcriptome analysis of WDR77 mutant patient-derived thyroid tissue showed changes in pathways enriched in the processes of cell cycle promotion and apoptosis inhibition. In summary, we report WDR77 mutations predisposing patients to nonsyndromic familial PTC and link germ-line WDR77 variants to human malignant disease.

Role of Age at Diagnosis in Defining Potential Familial Nonmedullary Thyroid Cancer in Kindreds With Two Affected Members.

The definition of familial nonmedullary thyroid cancer (FNMTC) in 2 or more first-degree relatives is controversial due to the high probability of observing a sporadic association when only 2 members of first-degree relatives are affected. To evaluate the role of age at diagnosis in differentiating the true cases of FNMTC. From a group of 721 papillary thyroid cancer (PTC) patients, 95 familial PTC (FPTC) patients with 2 first-degree relatives have been identified. They were split in 2 groups: Group 1 consisted of both the proband and the affected relative, with age at diagnosis ≤ 45 years; Group 2 consisted of proband and/or the affected family member, with age at diagnosis > 45 years. The clinical-pathological features and outcome of both FPTC groups were compared with 626 sporadic PTC patients (SPTC). Familial PTC patients with age at diagnosis ≤ 45 years, compared with the matched group of sporadic PTCs, had a more frequent multifocal, bilateral, and extrathyroidal extension of tumor and showed worse outcome. No differences were found between FPTC and SPTC patients with age > 45 years. At multivariate analysis, distant metastases, American Thyroid Association (ATA) risk, and FPTC ≤ 45 years were independent predictors of outcome. Based on the observation that PTC is more aggressive when the diagnosis is made in 2 family members, both with age < 45years, we suggest that the definition of FPTC in kindreds with 2 affected members should also take into account the age at diagnosis as a key element of familial cancer.

Long-Term Clinical Outcome in Familial and Sporadic Papillary Thyroid Carcinoma

Background: The definition and the behaviour of familial papillary thyroid cancer (FPTC) compared to the sporadic form (SPTC) are still debated. Some authors believe that only families with 3 or more affected members represent an actual example of familial diseases. Objectives: The objective of the study was to analyse the clinicopathological features and the outcome of sporadic and familial PTC patients also according to the number of affected members. Methods: Among 731 patients, we identified 101 (13.8%) with familial diseases, 79 with 2 affected members (FPTC-2) and 22 with 3 or more affected members (FPTC-3) followed for a mean period of 10 years. Results: FPTC patients had more frequently bilateral tumour (p = 0.007). No difference was found between the 2 groups for the other evaluated variables. At the time of the first follow-up (1–2 years after initial therapy), FPTC patients had a higher rate of persistent disease. However, at the last follow-up, the clinical outcome was not different between sporadic and familial patients. When the comparison between SPTC and FPTC was performed, according to the number of affected members, a significant trend between the 3 groups was observed for tumour diameter (p = 0.002) and bilaterality (p = 0.003), while we did not observe a significant trend for both response to initial therapy (p = 0.15) and last clinical outcome (p = 0.22). Conclusions: Our results suggest that, although the clinicopathological features of FPTC may be more aggressive, the long-term outcome is similar between FPTC and SPTC. A possible explanation is that PTC has a favourable prognosis, even when clinical presentation is more aggressive.

A Novel CHEK2 Mutation May Drive Familial Papillary Thyroid Cancer

A Novel <i>CHEK2</i> Mutation May Drive Familial Papillary Thyroid Cancer

Germline Mutations in Familial Papillary Thyroid Cancer

Thyroid cancer, predominantly of papillary histology (PTC), is a common cancer mostly diagnosed sporadically. Hereditary PTC is encountered in ~ 5% of cases and may present at an earlier age, with greater risks of metastasis and recurrence, compared with sporadic cases. The molecular basis of hereditary PTC is unknown in most cases. In this study, the genetic basis of hereditary PTC in three Brazilian families was investigated. Whole exome sequencing (WES) was carried out for probands in each family, and validated, pathogenic/likely pathogenic sequence variants (P/LPSVs) were genotyped in additional family members to establish their putative pathogenic role. Overall, seven P/LPSVs in seven novel genes were detected: p.D283N*ANXA3, p.Y157S*NTN4, p.G172W*SERPINA1, p.G188S*FKBP10, p.R937C*PLEKHG5, p.L32Q*P2RX5, and p.Q76*SAPCD1. These results indicate that these novel genes are seemingly associated with hereditary PTC, but extension and validation in other PTC families are required.

FAMILIAL PAPILLARY THYROID CARCINOMA: A CASE SERIES

The natural history and inheritance of familial papillary thyroid carcinoma (FPTC) remain unclear. A specific genetic defect responsible for this condition and its inheritance is yet to be established. The penetrance, mode of inheritance and treatment of this familial thyroid condition are different from other familial thyroid conditions (familial medullary thyroid cancer). Presented here is a family of four sisters in which three developed multifocal PTC. A 47-year-old lady presented with incidental finding of multinodular goitre and normal thyroid function. She had three other sisters who were diagnosed with PTC at age 46, 48 and 49 years. Detailed clinical history of her sisters was gathered from them over telephone as they all moved to different parts of world in their twenties. Literature review was carried out to find similar patients reported in literature. Environmental factors were less important in the development of PTC in this family. It was also interesting that all three were diagnosed with the condition at a very similar age. FPTC behaviour was not more aggressive than sporadic form of disease. There is not enough evidence in literature to suggest prophylactic thyroidectomy in relatives of patients with PTC. Since the exact inheritance pattern of this condition is not known, detailed family history is important in patients with thyroid disorders to identify high-risk patients. Genetic factors are much more important than environmental factors in the development of this condition. The first-degree relatives should be assessed clinically for further investigations if two individuals in the same family develop the condition at similar age.Key words: Familial follicular thyroid cancer, familial papillary thyroid cancer, papillary thyroid cancer

Abstract #1072: Thyrotoxic Periodic Paralysis as The First Presentation of a Patient with Locally Advanced Familial Papillary Thyroid Cancer

Abstract #1072: Thyrotoxic Periodic Paralysis as The First Presentation of a Patient with Locally Advanced Familial Papillary Thyroid Cancer

Abstract #1001: Extremely Aggressive Papillary Thyroid Cancer (PTC) with Widespread Metastases Including Spleen and Clear Cell Renal Cell Carcinoma (RCC) in one Patient: An Unknown Syndromic Entity or Manifestation of Familial PTC?

Abstract #1001: Extremely Aggressive Papillary Thyroid Cancer (PTC) with Widespread Metastases Including Spleen and Clear Cell Renal Cell Carcinoma (RCC) in one Patient: An Unknown Syndromic Entity or Manifestation of Familial PTC?

Genetic Heterogeneity of HER2 Amplification and Telomere Shortening in Papillary Thyroid Carcinoma.

Extensive research is dedicated to understanding if sporadic and familial papillary thyroid carcinoma are distinct biological entities. We have previously demonstrated that familial papillary thyroid cancer (fPTC) cells exhibit short relative telomere length (RTL) in both blood and tissues and that these features may be associated with chromosome instability. Here, we investigated the frequency of HER2 (Human Epidermal Growth Factor Receptor 2) amplification, and other recently reported genetic alterations in sporadic PTC (sPTC) and fPTC, and assessed correlations with RTL and BRAF mutational status. We analyzed HER2 gene amplification and the integrity of ALK, ETV6, RET, and BRAF genes by fluorescence in situ hybridization in isolated nuclei and paraffin-embedded formalin-fixed sections of 13 fPTC and 18 sPTC patients. We analyzed BRAFV600E mutation and RTL by qRT-PCR. Significant HER2 amplification (p = 0.0076), which was restricted to scattered groups of cells, was found in fPTC samples. HER2 amplification in fPTCs was invariably associated with BRAFV600E mutation. RTL was shorter in fPTCs than sPTCs (p < 0.001). No rearrangements of other tested genes were observed. These findings suggest that the association of HER2 amplification with BRAFV600E mutation and telomere shortening may represent a marker of tumor aggressiveness, and, in refractory thyroid cancer, may warrant exploration as a site for targeted therapy.

Genetic predisposition for nonmedullary thyroid cancer.

Nonmedullary thyroid cancer (NMTC) can be sporadic or can occur as a component cancer as part of several well-described hereditary cancer syndromes. NMTC, particularly papillary thyroid cancer, also can occur by itself in families and is often termed familial NMTC or familial papillary thyroid cancer. The occurrence of NMTC in families, along with extensive population-based evidence from patients with sporadic thyroid cancer, together suggest that NMTC has a strong genetic component, only a small proportion of which has been characterized to date. Advances in genetic and genomic technology have rapidly advanced our understanding of the complex nature of NMTC susceptibility, although much remains to be explained. Herein, we describe the current state of knowledge, starting with a brief review of hereditary syndromic causes and moving on to describe recent data using modern genomic approaches to identifying genes involved in the predisposition to NMTC.

MiR-20a is upregulated in anaplastic thyroid cancer and targets LIMK1.

BackgroundThere have been conflicting reports regarding the function of miR-20a in a variety of cancer types and we previously found it to be dysregulated in sporadic versus familial papillary thyroid cancer. In this study, we studied the expression of miR-20a in normal, benign and malignant thyroid samples, and its effect on thyroid cancer cells in vitro and in vivo.Methodology/Principal FindingsThe expression of miR-20a in normal, benign and malignant thyroid tissue was determined by quantitative RT-PCR. Thyroid cancer cells were transfected with miR-20a and the effect on cellular proliferation, tumor spheroid formation, and invasion was evaluated. Target genes of miR-20 were determined by genome-wide mRNA expression analysis with miR-20a overexpression in thyroid cancer cells and target prediction database. Target genes were validated by quantitative PCR and immunoblotting, and luciferase assays. MiR-20a expression was significantly higher in anaplastic thyroid cancer than in differentiated thyroid cancer, and benign and normal thyroid tissues. MiR-20a significantly inhibited thyroid cancer cell proliferation in vitro (p<0.01) and in vivo (p<0.01), tumor spheroid formation (p<0.05) and invasion (p<0.05) in multiple thyroid cancer cell lines. We found that LIMK1 was a target of miR-20a in thyroid cancer cell lines and direct knockdown of LIMK1 recapitulated the effect of miR-20a in thyroid cancer cells.Conclusions/SignificanceTo our knowledge, this is the first study to demonstrate that miR-20a plays a role as a tumor suppressor in thyroid cancer cells and targets LIMK1. Our findings suggest the upregulated expression of miR-20a in anaplastic thyroid cancer counteracts thyroid cancer progression and may have therapeutic potential.

Establishing a Familial Basis for Papillary Thyroid Carcinoma Using the Utah Population Database

Determining if relatives of patients diagnosed as having papillary thyroid carcinoma (PTC) are at increased risk of developing the same cancer--and if so, which relatives and to what degree--would help identify those who require closer clinical attention. This could lead to earlier cancer detection and improved prognoses. To define the familial risk of PTC using a unique population research database. Retrospective review at a tertiary care facility using the Utah Population Database, which is linked to medical records and the Utah Cancer Registry, from 1966 through 2011. The study population comprised 4460 patients diagnosed as having PTC in Utah between 1966 and 2011 and their first- through fifth-degree relatives and spouses. These patients were compared 5:1 with matched, population-based controls. Statistically significant increased risk of PTC in any first- through fifth-degree relatives or spouses of patients diagnosed as having this cancer. First-, second-, and third-degree relatives of PTC probands had a significant increased risk of developing this cancer compared with population controls. First-degree relatives of probands were at a 5.4-fold increased risk (P < 10(-15)) of being diagnosed as having this cancer themselves. Second- and third-degree relatives had a 2.2-fold (P < 10(-11)) and 1.8-fold increased risk (P < 10(-8)), respectively. Siblings of probands were at highest risk (odd ratio, 6.8; P < 10(-15)). There was no significant increased risk observed in spouses of probands. In the largest population study to date, a high risk of PTC is confirmed in first-degree relatives. Furthermore, significant increased risk extends to second- and third-degree relatives but not to spouses of probands. Translational studies are needed to better define the genetic predisposition to familial papillary thyroid cancer and for the development and implementation of optimal screening approaches.

Familial multinodular goiter syndrome with papillary thyroid carcinomas: mutational analysis of the associated genes in 5 cases from 1 Chinese family

BackgroundFamilial papillary thyroid cancer (fPTC) is recognized as a distinct entity only recently and no fPTC predisposing genes have been identified. Several potential regions and susceptibility loci for sporadic PTC have been reported. We aimed to evaluate the role of the reported susceptibility loci and potential risk genomic region in a Chinese familial multinodular goiter (fMNG) with PTC family.MethodsWe sequenced the related risk genomic regions and analyzed the known PTC susceptibility loci in the Chinese family members who consented to join the study. These loci included (1) the point mutations of the BRAF and RET; (2) the possible susceptibility loci to sporadic PTC; and (3) the suggested potential fMNG syndrome with PTC risk region.ResultsThe members showed no mutations in the common susceptible BRAF and RET genomic region, although contained several different heterozygous alleles in the RET introns. All the members were homozygous for PTC risk alleles of rs966423 (C) at chromosome 2q35, rs2910164 (C) at chromosome 5q24 and rs2439302 (G) at chromosome 8p12; while carried no risk allele of rs4733616 (T) at chromosome 8q24, rs965513 (A) or rs1867277 (A) at chromosome 9q22 which were associated with radiation-related PTC. The frequency of the risk allele of rs944289 (T) but not that of rs116909374 (T) at chromosome 14q13 was increased in the MNG or PTC family members.ConclusionsOur work provided additional evidence to the genetic predisposition to a Chinese familial form of MNG with PTC. The family members carried quite a few risk alleles found in sporadic PTC; particularly, homozygous rs944289 (T) at chromosome 14q13 which was previously shown to be linked to a form of fMNG with PTC. Moreover, the genetic determinants of radiation-related PTC were not presented in this family.

Telomere Abnormalities and Chromosome Fragility in Patients Affected by Familial Papillary Thyroid Cancer

Genomic instability has been proposed to play a role in cancer development and can occur through different mechanisms including telomere association and telomere loss. Studies carried out in our unit have demonstrated that familial papillary thyroid cancer (fPTC) patients display an imbalance, at the germinal level, in telomere-telomerase complex. We aimed to verify whether familial fPTC patients show an increased spontaneous chromosome fragility. To this purpose, we compared telomeric fusions and associations as well as other chromosomal fragility features by conventional and molecular cytogenetic analyses, in phytohemagglutinin stimulated T-lymphocytes from fPTC patients, unaffected family members, sporadic papillary thyroid cancer patients, and healthy subjects. We demonstrate that fPTC patients have a significant increase in spontaneous telomeric associations and telomeric fusions compared with healthy subjects and sporadic cases in the frame of an otherwise common spontaneous chromosome fragility pattern. A quantitative fluorescence in situ hybridization analysis demonstrates that familial cases display a significant decrease in the telomeric peptide nucleic acid-fluorescence in situ hybridization signal intensity in the metaphase chromosome. Moreover, three copies of the hTERT gene were found only in familial cases, although the result was not statistically significant. These results contribute in defining familial thyroid cancer as a clinical entity characterized by an altered telomere stability, which may be associated with the predisposition to develop the familial form of thyroid cancer.

Papillary thyroid cancer: sporadic or inherited?

Background: Papillary thyroid cancer (PTC) is one of the most common thyroid malignancies, with an increase in incidence rates over the past few decades. Although the exact cause of thyroid cancer in most patients is still unclear, the possibility of genetic predisposition to PTC cannot be overlooked. Here, we report a case study of PTC, in which the family was extensively affected, with each family member diagnosed with either benign or malignant thyroid neoplasms, or functional thyroid disorder. Method: A 57-year-old white female with a past medical history of hypothyroidism, and a significant family history of multiple thyroid cancers, was found to have new onset thyroid nodules during a routine screening ultrasound. Fine needle aspiration revealed suspicious papillary carcinoma (follicular variant). The patient underwent total thyroidectomy. Results: The histology report revealed total colloid nodules in the right lobe with focal calcification, lymphocytic thyroiditis, and two foci of papillary microcarcinoma. The patient subsequently underwent radioactive iodine ablation therapy, along with pilocarpine and thyrogen injection. Conclusion: This case study illustrates the need for awareness of the possibility of genetic predisposition to, as well female preponderance of, familial PTC.

Lack of Mutations of the Telomerase RNA Component in Familial Papillary Thyroid Cancer with Short Telomeres

The occurrence of familial papillary thyroid cancer (FPTC) is well established but no susceptibility genes for this disease have been discovered. Our group has recently demonstrated that patients with FPTC have shorter telomeres, not associated with mutations in telomerase reverse transcriptase, gene than patients with sporadic papillary thyroid cancer (SPTC), healthy subjects (HS), and unaffected family members (UFMs). Several diseases, however, have short telomeres associated with mutations in the telomerase RNA component (TERC) gene or in the shelterin complex (POT1, RAP1, TIN2, TPP1, TRF1, and TRF2) genes. The objective of the present study was to verify whether short telomeres observed in FPTC patients were related to mutations in TERC or shelterin genes. Sixty-six patients with FPTC, 46 UFMs, 111 patients with SPTC, and 153 HS were analyzed by polymerase chain reaction followed by denaturing high performance liquid chromatography analysis and direct sequencing for the presence of TERC or shelterin gene mutations. When present, single-nucleotide polymorphisms were tested by χ(2) analysis at the genotypic, allelic, and haplotypic levels. The entire sequence of the TERC gene was analyzed with particular attention to known mutations known to be associated with short telomeres. All samples appeared to be homozygous wild type for A-771G, C-99G, G305A, G322A, C323T, C408G, G450A, T467C, G508A, A514G, G623A, and C727G substitutions and for the 378Δ→3' deletion in the TERC gene. In addition, upon analysis of all samples for shelterin proteins, we observed a significant decrease in POT1 and RAP1 protein expression in the blood of FPTC patients compared with SPTC subjects. However, no mutations or polymorphisms were found when in the coding sequences of both genes. To our knowledge this is the first study of TERC mutations or alterations in the shelterin complex in relation to FPTC. Shorter telomeres observed in FPTC are not linked to mutations or polymorphisms in TERC, POT1, or RAP1 genes.

MiR-886-3p Regulates Cell Proliferation and Migration, and Is Dysregulated in Familial Non-Medullary Thyroid Cancer

BackgroundThe molecular basis and characteristics of familial non-medullary thyroid cancer are poorly understood. In this study, we performed microRNA (miRNA) profiling of familial and sporadic papillary thyroid cancer tumor samples.Methodology/Principal FindingsGenome wide miRNA profiling of sporadic and familial papillary thyroid cancer was performed. Differentially expressed miRNAs were validated by quantitative RT-PCR. Ectopic expression of miR-886-3p in thyroid cancer lines was performed to identify pathways targeted by the miRNA, as well as, to determine its effect on tumor cell biology. We found four differentially expressed miRNAs between familial and sporadic papillary thyroid cancer tumor samples. MiR-886-3p and miR-20a were validated to be differentially expressed by 3- and 4-fold, respectively. Pathway analysis of genome-wide expression data on cells overexpressing miR-886-3p and target prediction analysis showed genes involved in DNA replication and focal adhesion pathways were regulated by miR-886-3p. Overexpression of miR-886-3p in thyroid cancer cell lines significantly inhibited cellular proliferation, the number and size of spheroids and cellular migration. Additionally, overexpression of miR-886-3p increased the number of cells in S phase.Conclusions/SignificanceOur findings for the first time suggest that miR-886-3p plays an important role in thyroid cancer tumor cell biology and regulates genes involved in DNA replication and focal adhesion. Thus, miR-886-3p may play a role in the initiation and or progression of papillary thyroid cancer.