Molecular and clinical features of papillary thyroid cancer in adult patients with a non-classical phenotype.

Purpose: Genotyping is fundamental in papillary thyroid cancer (PTC) and helps to enhance diagnosis and prognosis and determine appropriate treatments. The phenotype-genotype association in PTC was previously studied, with BRAF V600E characterizing classic PTC and tall-cell PTC and RAS mutations characterizing follicular-variant PTC. In clinic, some non-classical histological subtypes of PTC were also identified, however, their genotype remains unclear. In this study, we collected samples of these non-classical PTC after the exclusion of classic phenotypes and examined their phenotypes, genotype and the relationship between phenotype and genotype. Methods: We screened out non-classical PTC by excluding classical PTC from 1,059 different thyroid samples, and a total of 24 cases was obtained and described from the morphological features, which is rare in differentiated PTC. DNA/RNA sequencing was performed using 18 available samples to describe the genetic features. Results: PTC with the non-classical phenotype were characterized cuboidal to low columnar tumor cells with subtle nuclear features of PTC and without discernible nuclear elongation, concurrently with dense microfollicles, delicate papillae or solid nodules with delicate fibrovascular cores. They were associated with lymphatic vessel invasion (P<0.001) but not with a worse prognosis (P=0.791). Gene fusions were identified in 14 of 18 (77.8%) cases, including eight fusions of NTRK and six fusions of RET. The high percentage of fusions in this papillary thyroid cancer subgroup suggested a correlation of gene fusions with the phenotype that does not belong to the BRAF V600E-mutant or RAS-mutant group. Conclusions: Our study retrospectively screened a large cohort of different thyroid tissue samples, and presented the histopathological and genetic features of a non-classical phenotype of PTC from 24 patients. It may contribute to diagnose in PTC, and patients of these non-classical phenotype may benefit from targeted therapy, compared to a natural patient cohort without selection.

Expression Pattern and Clinicopathological Relevance of the Indoleamine 2,3-Dioxygenase 1/Tryptophan 2,3-Dioxygenase Protein in Colorectal Cancer.

Aims. Cancer cells use the indoleamine 2,3-dioxygenase 1 (IDO1) pathway to suppress the host's immune response in order to facilitate survival, growth, invasion, and metastasis of malignant cells. Higher IDO1 expression was shown to be involved in colorectal cancer (CRC) progression and to be correlated with impaired clinical outcome. However, the potential correlation between the expression of IDO1 in a CRC population with a low mutation rate of the APC gene remains unknown. Material and Methods. Tissues and blood samples were collected from 192 CRC patients. The expressions of IDO1, tryptophan 2,3-dioxygenase (TDO2), and beta-catenin proteins were analyzed by immunohistochemistry. Microsatellite instability (MSI) was determined by PCR amplification of microsatellite loci. Results. The results showed that high IDO1 or TDO2 protein expression was associated with characteristics of more aggressive phenotypes of CRC. For the first time, they also revealed a positive correlation between the abnormal expression of beta-catenin and IDO1 or TDO2 proteins in a CRC population with a low mutation rate of APC. Conclusion. We concluded that an IDO1-regulated molecular pathway led to abnormal expression of beta-catenin in the nucleus/cytoplasm of CRC patients with low mutation rate of APC, making IDO1 an interesting target for immunotherapy in CRC.

MiRNA-221 negatively regulated downstream p27Kip1 gene expression involvement in pterygium pathogenesis.

PURPOSE: MiRNAs are small noncoding RNAs that have been implicated in tumor development. They regulate target gene expression either by mRNA degradation or by translation repression. Activation of ß-catenin has been linked to pterygium progression. Here, we hypothesize that ß-catenin-associated miRNA, miRNA-221, and downstream p27Kip1 gene expression are correlated with the pathogenesis of pterygium. METHODS: We collected 120 pterygial and 120 normal conjunctival samples for this study. Immunohistochemistry and real-time reverse transcription (RT)-PCR were performed to determine ß-catenin protein localization, miR-221, and p27Kip1 gene expression. Pterygium cell line (PECs) cell models were used to confirm the effect of ß-catenin, miR-221, and p27Kip1 gene in the proliferation of pterygium cells. RESULTS: Seventy-two (60.0%) pterygial specimens showed high miR-221 expression levels, which was significantly higher than the control groups (13 of 120, 10.8%, p<0.0001). MiR-221 expression was significantly higher in ß-catenin-nuclear/cytoplasmic-positive groups than in ß-catenin membrane-positive and negative groups (p=0.001). We also found that p27Kip1 gene expression in pterygium was negatively correlated with miR-221 expression (p=0.002). In the clinical association, miR-221 expression was significantly higher in the fleshy and intermediate groups than in the atrophic group (p=0.007). The association of miR-221, p27Kip1 and proliferation of pterygium were also confirmed in the PECs model. CONCLUSIONS: Our study demonstrated that activation of ß-catenin in pterygium may interact with miR-221, resulting in p27Kip1 gene downregulation that influences pterygium pathogenesis.