A population-based study of the three major variants of papillary thyroid carcinoma.

OBJECTIVE: To explore the clinicopathological features and relative prognostic risks of the three major variants of papillary thyroid carcinoma (PTC). METHODS: We retrospectively analyzed the clinicopathological characteristics and prognoses of patients with the three major PTC variants, conventional papillary thyroid carcinoma (CPTC), follicular-variant papillary carcinoma (FVPTC), and tall-cell papillary thyroid carcinoma (TCPTC), based on data from the Surveillance, Epidemiology, and End Results database from 2005 to 2009. RESULTS: A total of 29,555 patients were enrolled. In terms of their demographic and clinicopathological characteristics, TCPTC had the highest prevalence of older patients, men, patients with locally advanced stage (T stage and N stage), and mortality, while FVPTC had the lowest prevalence in relation to these factors. The three variants differed significantly in terms of 5-year overall survival and 5-year disease-specific survival. Cox regression analysis identified male sex, age ≥45 years, and higher American Joint Committee on Cancer and TNM stage as independent factors predicting a poor prognosis in relation to both overall and disease-specific survival. CONCLUSIONS: CPTC, FVPTC, and TCPTC have different clinicopathological characteristics and prognoses, indicating the need for different treatment strategies for these three variants of PTC.

Baicalein induced apoptosis and autophagy of undifferentiated thyroid cancer cells by the ERK/PI3K/Akt pathway.

Thyroid cancer is the most common endocrine system malignancy, and undifferentiated thyroid cancer is one of the most invasive tumors. Studies have found that baicalein, a major flavonoid separated from the root of Scutellaria baicalensis Georgi, has an inhibitory effect on a variety of malignant tumor cells. However, the effect of baicalein on undifferentiated thyroid cancer has not yet been investigated. In the present study, follicular undifferentiated thyroid cancer cells (FRO) were treated with different concentrations of baicalein (10 µM, 20 µM, 40 µM, 80 µM) for 12 h, 24 h, 36 h, or 48 h; then, the cell viability and clonogenicity were measured. Cell cycles and cell apoptosis were measured by flow cytometer after FRO cells were treated with baicalein for 36 h or 48 h. After FRO cells were treated with baicalein for 48 h, the expression of apoptosis-related proteins (Bcl-2, Bax, Caspase-3 and Caspase-8), autophagy-related proteins (Beclin-1, p62, Atg5 and Atg12) and the phosphorylation levels of ERK and Akt in FRO cells were measured by Western blot. The results showed that baicalein reduced the cell viability and cell colony numbers of FRO cells in a dose- and time-dependent manner. Baicalein also induced cell apoptosis and arrested the cell cycles of FRO cells. Baicalein decreased the ratio of Bcl-2/Bax but increased the expression of Caspase-3 and Caspase-8. Furthermore, baicalein induced autophagy in FRO cells. It significantly increased the expression of Beclin-1, Atg5, p62 and Atg12. Baicalein significantly decreased the ratios of p-ERK/ERK and p-Akt/Akt, indicating that it suppressed the ERK and PI3K/Akt pathways. In conclusion, baicalein could suppress the growth of undifferentiated thyroid cancer cells by inducing apoptosis and autophagy. The inhibition of the ERK and PI3K/Akt pathways may be involved in the mechanism.

The clinicopathological significance of Ki67 in papillary thyroid carcinoma: a suitable indicator?

BACKGROUND: To explore Ki67 expression in papillary thyroid carcinoma (PTC) and its clinical-pathological significance. METHODS: A total of 776 consecutive PTC and benign thyroid disease patients underwent thyroidectomy at Shanghai General Hospital from January 2013 to December 2015 and were retrospectively analysed. Ki67 expression was determined in the PTC and benign thyroid disease tissues, and other clinicopathological factors were identified via statistical analyses. RESULTS: The Ki67 expression intensity in the PTC group was significantly higher than that in the benign thyroid disease group. In the PTC group, a tumour size ≥ 1 cm and coexistence with thyroiditis were significantly associated with the Ki67 expression intensity. The TGAb and TPOAb plasma levels were linearly correlated with the Ki67 expression intensity. Moreover, the tumour size and Ki67 expression intensity also showed a linear correlation. Receiver operating characteristic (ROC) curve analysis suggested that the optimal cut-off value of Ki67 was 2.50%. Two groups divided by Ki67 cut-off values showed significant differences in the recurrence survival rate. CONCLUSIONS: Ki67 is a suitable biomarker for distinguishing PTC from benign thyroid disease. Ki67 expression was related to the tumour size, thyroiditis and plasma levels of TGAb and TPOAb in PTC. Ki67 could be used as a prognostic indicator in PTC. Patients with high Ki67 expression are more likely to experience disease recurrence.

A Positive Feed-Forward Loop between LncRNA-CYTOR and Wnt/ß-Catenin Signaling Promotes Metastasis of Colon Cancer.

We previously demonstrated that long non-coding RNA cytoskeleton regulator RNA (CYTOR), also known as Linc00152, was significantly overexpressed in colon cancer and conferred resistance to oxaliplatin-induced apoptosis. At the same time, elevated CYTOR expression was also reported in gastric cancer and exerted influences on epithelial-mesenchymal transition (EMT) markers. However, the precise mechanism by which CYTOR promotes the EMT phenotype and cancer metastasis remains poorly understood. Here, we showed that loss of epithelial characteristics and simultaneous gain of mesenchymal features correlated with CYTOR expression. Knockdown of CYTOR attenuated colon cancer cell migration and invasion. Conversely, ectopic expression of CYTOR induced an EMT program and enhanced metastatic properties of colon cancer cells. Mechanistically, the binding of CYTOR to cytoplasmic ß-catenin impeded casein kinase 1 (CK1)-induced ß-catenin phosphorylation that enabled it to accumulate and translocate to the nucleus. Reciprocally, ß-catenin/TCF complex enhanced the transcription activity of CYTOR in nucleus, thus forming a positive feed-forward circuit. Moreover, elevated CYTOR, alone or combined with overexpression of nuclear ß-catenin, was predictive of poor prognosis. Our findings suggest that CYTOR promotes colon cancer EMT and metastasis by interacting with ß-catenin, and the positive feed-forward circuit of CYTOR-ß-catenin might be a useful therapeutic target in antimetastatic strategy.

Periostin silencing suppresses the aggressive phenotype of thyroid carcinoma cells by suppressing the Akt/thyroid stimulating hormone receptor axis.

Clinical evidence indicates that high periostin expression correlates with aggressive phenotype in thyroid carcinoma. However, the biological roles of periostin in thyroid carcinoma development and progression are still unclear. In this study, we explored the effects of periostin silencing on thyroid carcinoma cell growth, invasion, and tumorigenesis. We also studied the impact of periostin on the activation of phosphoinositide 3-kinase (PI3-K)/Akt signaling, which is involved in the pathogenesis of thyroid carcinoma. It was found that downregulation of periostin significantly inhibited the proliferation, colony formation, and invasion in both FTC-133 and BCPAP thyroid carcinoma cells. In vivo tumorigenic studies confirmed that periostin depletion retarded the growth of subcutaneous FTC-133 xenograft tumors, which was coupled with a significant decline in the percentage of Ki-67-positive proliferating cells. Western blot analysis demonstrated that periostin downregulation caused a marked inhibition of thyroid stimulating hormone receptor (TSHR) expression and Akt phosphorylation in FTC-133 and BCPAP cells. Co-expression of constitutively active Akt (CA-Akt) significantly reversed periostin-mediated downregulation of TSHR. Most importantly, overexpression of TSHR or CA-Akt rescued FTC-133 cells from periostin-induced growth and invasion suppression. Collectively, periostin regulates thyroid carcinoma growth and progression via the Akt/TSHR axis and represents a promising therapeutic target for this malignancy.

Long non-coding RNA HNF1A-AS1 mediated repression of miR-34a/SIRT1/p53 feedback loop promotes the metastatic progression of colon cancer by functioning as a competing endogenous RNA.

In recent years, accumulating evidence indicates that long noncoding RNAs (lncRNAs) have emerged as powerful influence factors in the progression of multiple malignancies. Dysregulation of lncRNA HNF1A-antisense 1 (HNF1A-AS1) has been reported in many types of human cancers, and studies on HNF1A-AS1 function in cancers revealed that HNF1A-AS1could act as either oncogene or tumor suppressor. Nevertheless, the functional involvement of HNF1A-AS1 in colon cancer remains unknown. In this study, we reported that HNF1A-AS1 was frequently upregulated in colon cancer tissues and associated with poor prognosis. Upregulated HNF1A-AS1 promoted colon cancer cell viability, migration and invasion both in vitro and in vivo. HNF1A-AS1 silencing impaired tumor growth and metastasis in xenograft model assay. Moreover, HNF1A-AS1 functioned as an oncogene in metastasis of colon cancer in part through serving as a competing endogenous RNA to modulate miRNA-34a expression, subsequently with repression of miR-34a/SIRT1/p53 feedback loop and activation of canonical Wnt signaling pathway. Our results demonstrated that HNF1A-AS1 mediated the metastatic progression of colon cancer in part through miR-34a/p53 signaling axis, and established its candidacy as a new prognostic biomarker and a potential novel therapeutic target.

LncRNA-ATB mediated E-cadherin repression promotes the progression of colon cancer and predicts poor prognosis.

BACKGROUND: Long non-coding RNA-activated by TGF-ß (lncRNA-ATB) promotes the invasion-metastasis cascade in hepatocellular carcinoma via downregulating E-cadherin (E-cad) and inducing epithelial-to- mesenchymal transition (EMT) and is clinically significant in human colon cancer. However, its molecular mechanisms in colon cancer progression remain unclear. This study aimed to elucidate the role of lncRNA-ATB and its clinical value in colon cancer. METHODS: Expression levels of lncRNA-ATB in colon cancer tissues and colon cancer cell lines were evaluated using quantitative real-time polymerase chain reaction. The clinicopathological significance and prognostic value of lncRNA-ATB were investigated, and roles of lncRNA-ATB in regulating E-cad and other EMT-related markers expression and colon cancer progression were evaluated in vitro. Expression levels of lncRNA-ATB and E-cad in human plasma were evaluated. RESULTS: Long non-coding RNA-activated by TGF-ß was upregulated in colon cancer tissues compared with adjacent mucosa (P < 0.001). LncRNA-ATB levels were also higher in metastatic cancer tissues (P < 0.001). Among the three highly invasive colon cancer cell lines, lncRNA-ATB levels were relatively higher with concurrent low levels of E-cad compared with levels in the three low-invasive cell lines. LncRNA-ATB expression correlated with pN stage (P < 0.01) and American Joint Committee on Cancer stage (P < 0.01). Striking differences were observed in overall survival and disease-free survival in cases with both high lncRNA-ATB expression and low E-cad expression. Reduction of lncRNA-ATB increased expression of epithelial markers E-cad, ZO-1, and decreased expression of mesenchymal markers ZEB1 and N-cadherin (N-cad), and significantly influenced colon cancer cell progression. Plasma lncRNA-ATB was upregulated in colon cancer patients one month after surgery (P < 0.05). CONCLUSIONS: Long non-coding RNA-activated by TGF-ß may act on colon tumorigenesis by suppressing E-cad expression and promoting EMT process, and lncRNA-ATB inhibition may provide a promising therapeutic option for suppressing colon cancer progression.

Enrichment of CCR6+Foxp3+ regulatory T cells in the tumor mass correlates with impaired CD8+ T cell function and poor prognosis of breast cancer.

CCR6(+) subset of CD4(+) regulatory T cells, a newly characterized subset of Tregs, has been reported to contribute to local immune inhibition. However, whether CCR6(+) Tregs are present in tumor environment and their relation to the prognosis of tumor remain to be elucidated. In this study, we found that CCR6(+) CD4(+) CD25(high) Tregs, expressing high levels of CD45RO, are dominantly enriched in tumor mass from patients with breast cancer. Furthermore, the frequency of CCR6(+) Tregs, but not CCR6(-) Tregs in tumor infiltrating lymphocytes (TILs), significantly increased in patients during tumor progression, which reversely correlated with decreased frequency of the IFN-gamma(+)CD8(+)T cells in TILs. Most importantly, the frequency of CCR6(+) Tregs, but not CCR6(-) Tregs, reversely correlated to the survival of patients with breast cancer. This study suggested that a new subset of tumor-resident Tregs, CCR6(+) Tregs, may be dominantly responsible for the immunosuppression in tumor immunity and a potential predictor of the poor prognosis of breast cancer.