PARP inhibitor shuts down the global translation of thyroid cancer through promoting Pol II binding to DIMT1 pause.

Thyroid cancer has become the most frequent endocrine-related malignancy. Currently, a mounting body of evidences support the clinical strategies for extending the benefit of PARP inhibitors beyond BRCA-mutant cancers. However, the functions and molecular mechanisms of PARP inhibitors in thyroid cancers (TCs) are not fully understood. Here, on the one hand, we revealed that niraparib promotes the accumulation of DNA damage in TCs. On the other hand, we indicated that niraparib inhibits the transcription of DIMT1 through promoting Pol II pausing in a PAR-dependent manner, subsequently leading to a global translation inhibition in TCs. Meanwhile, we found that niraparib activates the NF-κB signaling pathway by inhibiting the PARylation of p65, which decreases its ubiquitination and degradation level through E3 ubiquitin ligase RNF146. Moreover, bortezomib (a small molecule inhibitor of the NF-κB signaling pathway) could significantly enhance the anti-tumor effect of niraparib on TCs in vitro and in vivo. Our findings provide mechanistic supports for the efficacy of PARP inhibitors in cancer cells lacking BRCA-mutant.

Multi-omics profiling of papillary thyroid microcarcinoma reveals different somatic mutations and a unique transcriptomic signature.

BACKGROUND: Papillary thyroid microcarcinoma (PTMC) incidence has significantly increased, and some cases still exhibit invasive traits. The entire molecular landscape of PTMC, which can offer hints for the etiology of cancer, is currently absent. METHODS: We compared our findings with those for PTMC in the TCGA by analyzing the largest study at the current stage of whole exome sequencing and RNA-sequencing data from 64 patients with PTMC. Then, we systematically demonstrated the differences between the two PTMC subtypes based on multi-omics analyses. Additionally, we created a molecular prediction model for the PTMC subtypes and validated them among TCGA patients for individualized integrative assessment. RESULTS: In addition to the presence of BRAF mutations and RET fusions in the TCGA cohort, we also discovered a new molecular signature named PTMC-inflammatory that implies a potential response to immune intervention, which is enriched with AFP mutations, IGH@-ext fusions, elevated immune-related genes, positive peroxidase antibody, and positive thyroglobulin antibody. Additionally, a molecular prediction model for the PTMC-inflammatory patients was created and validated among TCGA patients, while the prognosis for these patients is poor. CONCLUSIONS: Our findings comprehensively define the clinical and molecular features of PTMC and may inspire new therapeutic hypotheses.

Integrated gene profiling of fine-needle aspiration sample improves lymph node metastasis risk stratification for thyroid cancer.

BACKGROUND: Lymph node metastasis risk stratification is crucial for the surgical decision-making of thyroid cancer. This study investigated whether the integrated gene profiling (combining expression, SNV, fusion) of Fine-Needle Aspiration (FNA) samples can improve the prediction of lymph node metastasis in patients with papillary thyroid cancer. METHODS: In this retrospective cohort study, patients with papillary thyroid cancer who went through thyroidectomy and central lymph node dissection were included. Multi-omics data of FNA samples were assessed by an integrated array. To predict lymph node metastasis, we built models using gene expressions or mutations (SNV and fusion) only and an Integrated Risk Stratification (IRS) model combining genetic and clinical information. Blinded histopathology served as the reference standard. ROC curve and decision curve analysis was applied to evaluate the predictive models. RESULTS: One hundred and thirty two patients with pathologically confirmed papillary thyroid cancer were included between 2016-2017. The IRS model demonstrated greater performance [AUC = 0.87 (0.80-0.94)] than either expression classifier [AUC = 0.67 (0.61-0.74)], mutation classifier [AUC = 0.61 (0.55-0.67)] or TIRADS score [AUC = 0.68 (0.62-0.74)] with statistical significance (p < 0.001), and the IRS model had similar predictive performance in large nodule [>1 cm, AUC = 0.88 (0.79-0.97)] and small nodule [≤1 cm, AUC = 0.84 (0.74-0.93)] subgroups. The genetic risk factor showed independent predictive value (OR = 10.3, 95% CI:1.1-105.3) of lymph node metastasis in addition to the preoperative clinical information, including TIRADS grade, age, and nodule size. CONCLUSION: The integrated gene profiling of FNA samples and the IRS model developed by the machine-learning method significantly improve the risk stratification of thyroid cancer, thus helping make wise decisions and reducing unnecessary extensive surgeries.

Based on different immune responses under the glucose metabolizing type of papillary thyroid cancer and the response to anti-PD-1 therapy.

Glucose metabolism-related genes play an important role in the development and immunotherapy of many tumours, but their role in thyroid cancer is ambiguous. To investigate the role of glucose metabolism-related genes in the development of papillary thyroid cancer (PTC) and their correlation with the clinical outcome of PTC, we collected transcriptomic data from 501 PTC patients in the Cancer Genome Atlas (TCGA). We performed nonnegative matrix decomposition clustering of 2752 glucose metabolism-related genes from transcriptome data and classified PTC patients into three subgroups (C1 for high activation of glucose metabolism, C2 for low activation of glucose metabolism and C3 for moderate activation of glucose metabolism) based on the activation of different glucose metabolism-related genes in 10 glucose metabolism-related pathways. We found a positive correlation between the activation level of glucose metabolism and the tumour mutation burden (TMB), neoantigen number, mRNA stemness index (mRNAsi), age, and tumour stage in PTC patients. Next, we constructed a prognostic prediction model for PTC using six glucose metabolism-related genes (PGBD5, TPO, IGFBPL1, TMEM171, SOD3, TDRD9) and constructed a nomogram based on the risk score and clinical parameters of PTC patients. Both the prognostic risk prediction model and nomogram had high stability and accuracy for predicting the progression-free interval (PFI) in PTC patients. Patients were then divided into high-risk and low-risk groups by risk score. The high-risk group was sensitive to paclitaxel and anti-PD-1 treatment, and the low-risk group was sensitive to sorafenib treatment. We found that the high-risk group was enriched in inflammatory response pathways and associated with high level of immune cell infiltration. To verify the accuracy of the prognostic prediction model, we knocked down PGBD5 in PTC cells and found that the proliferation ability of PTC cells was significantly reduced. This suggests that PGBD5 may be a relatively important oncogene in PTC. Our study constructed a prognostic prediction model and classification of PTC by glucose metabolism-related genes, which provides a new perspective on the role of glucose metabolism in the development and immune microenvironment of PTC and in guiding chemotherapy, targeted therapy and immune checkpoint blockade therapy of PTC.

Preoperative supplementation of calcitriol and calcium relieves symptom and extent of hypocalcemia in patients undergoing total thyroidectomy and bilateral central compartment neck dissection: A prospective, randomized, open-label, parallel-controlled clinical study.

Background: Hypocalcemia is the most common complication that challenges surgeons performing total thyroidectomy. Conventional postoperative calcium and calcitriol supplement has been reportedly effective; however, a time lag has been reported before taking effect. Therefore, the role of preoperative strategy is yet to be determined. Study design: In this prospective, randomized, open-label, parallel-controlled phase II clinical study (registration number: ChiCTR2200059815), a short-term preoperative administration of calcitriol and calcium was proposed in 210 patients undergoing total thyroidectomy and bilateral central compartment neck dissection. Patients were recruited and randomized (1:1:1) into three groups: (A) combined (preoperative calcitriol and calcium), (B) calcium only (preoperative calcium only), and (C) control (no preoperative intervention). Finally, a total of 172 patients were qualified for final analysis. Results: Our data showed that 16 of 63 patients (25.4%) in the combined group had symptomatic hypocalcemia, whereas more patients from the control group (25 of 57 patients, 43.9%, P = 0.033) had symptomatic hypocalcemia. Further, the postoperative calcium level in the combined group is higher than in the control group (2.15 ± 0.15 vs. 2.09 ± 0.15 mmol/L, P = 0.031). Moreover, patients from the combined group showed lower calcium rates of <2.00 mmol/L (12.7% vs. 28.1%, P = 0.036). Remarkably, compared with the control group, patients with transient hypoparathyroidism in the combined group showed fewer rates for both symptomatic and biochemical hypocalcemia (28.6% vs. 61.1% for symptomatic hypocalcemia; 47.6% vs. 75% for biochemical hypocalcemia). Patients without transient hypoparathyroidism in all three groups showed no significant difference in rates for either symptomatic or biochemical hypocalcemia, indicating that this preoperative strategy is only effective for patients with transient hypoparathyroidism. We did not observe such beneficial effects in patients from the calcium group. Conclusions: Preoperative administration of calcitriol and calcium could reduce symptomatic and biochemical hypocalcemia, especially for those with transient hypoparathyroidism. Moreover, this maneuver could be recommended as a clinical routine in patients undergoing total thyroidectomy and bilateral central compartment neck dissection. Clinical Trial Registration: http://www.chictr.org.cn/edit.aspx?pid=164316&htm=4, identifier ChiCTR2200059815.

Ultrasound features of medullary thyroid cancer as predictors of biological behavior.

BACKGROUND: Medullary thyroid cancer (MTC) has more aggressive behavior and poor prognosis. Ultrasound (US) has facilitated the qualitative diagnosis of thyroid nodules, however, some MTC may be diagnosed as a benign nodule on ultrasound because ultrasound features of malignancy are lacking. The aim of the study was to investigate the association between ultrasound features and biological behavior of MTC. METHODS: Ultrasound findings and medical records of patients with MTC between Jan 2015 to Jun 2017 were retrospectively reviewed at Tianjin Medical University Cancer Institute and Hospital. MTC were categorized using modified TI-RADS classification, then were classified as "malignant" (m-MTC) or "US-low-suspicious" (l-MTC). We compared the biological behavior between the two groups, and further analyzed the risk factors for the recurrence. RESULTS: A total of 78 patients were enrolled, of which 55 m-MTC (70.5%) and 23 l-MTC (29.5%) were identified. The N staging of the m-MTC was significantly higher than that of l-MTC(P = 0.000). The preoperative serum Ct level in m-MTC were significantly higher than that of l-MTC(P = 0.035). Biochemical cure were more frequent in l-MTC than that of m-MTC (P = 0.002). Disease recurrence rates were 19.7% (14 of 71). Disease recurrence was more frequent in m-MTC than that of l-MTC (P = 0.013). Disease recurrence was positively associated with extrathyroid extension (P = 0.047), N staging (P = 0.003), preoperative serum Ct level (P = 0.009) and negatively associated with biochemical cure(P = 0.000). In multivariable Cox regression analysis, extrathyroid extension and biochemical cure were independent risk factors for recurrence of MTC. CONCLUSIONS: L-MTC has a more indolent character than m-MTC. The extrathyroid extension and biochemical cure were independent risk factors for recurrence of MTC.

G9a regulates tumorigenicity and stemness through genome-wide DNA methylation reprogramming in non-small cell lung cancer.

BACKGROUND: Eukaryotic histone methyltransferases 2 (EHMT2 or G9A) has been regarded as a potential target for non-small cell lung cancer (NSCLC) therapy. This study investigated the regulatory roles of G9A in tumorigenesis and stemness in NSCLC. We isolated and enriched tumor-initiating cells (TIC) from surgically resected NSCLC tissues by FACS and sphere formation assays. We then knocked down G9A using shRNA and carried out genome-wide 850K methylation array and RNA sequencing analyses. We carried out in vivo tumorigenecity asssay using mice xenografts and examined G9A interactions with its novel target using chromatin Immunoprecipitation (ChIP). RESULTS: We identified 67 genes hypomethylated and 143 genes upregulated following G9A knockdown of which 43 genes were both hypomethylated and upregulated. We selected six genes (CDYL2, DPP4, SP5, FOXP1, STAMBPL1, and ROBO1) for validation. In addition, G9A expression was higher in TICs and targeting G9a by shRNA knockdown or by selective inhibitor UNC0642 significantly inhibited the expression of cancer stem cell markers and sphere forming capacity, in vitro proliferation, and in vivo growth. Further, transient overexpression of FOXP1, a protein may promote normal stem cell differentiation, in TICs resulted in downregulation of stem cell markers and sphere forming capacity and cell proliferation in vitro indicating that the genes we identified are directly regulated by G9A through aberrant DNA methylation and subsequent expression. Similarly, ChIP assay has shown that G9a interacts with its target genes through H3K9me2 and downregulation of H3K9me2 following G9a knockdown disrupts its interaction with its target genes. CONCLUSIONS: These data suggest that G9A is involved in lung cancer stemness through epigenetic mechanisms of maintaining DNA methylation of multiple lung cancer stem cell genes and their expression. Further, targeting G9A or its downstream genes could be a novel therapeutic approach in treating NSCLC patients.

Identification of potential pathogenic candidates or diagnostic biomarkers in papillary thyroid carcinoma using expression and methylation profiles.

The mechanisms underlying the pathogenesis of papillary thyroid carcinoma (PTC) have not yet been elucidated. The aim of the current study was to identify potential pathogenic biomarkers in PTC by comprehensively analyzing gene expression and methylation profiles, and to increase the understanding of PTC pathogenesis. The gene expression profiles of the GSE97001 and GSE83520 datasets, the miRNA expression profiles of the GSE73182 dataset, and the DNA methylation profiles of the GSE86961 and GSE97466 datasets were downloaded from Gene Expression Omnibus database. The differentially expressed genes (DEGs) and the differentially expressed microRNAs (DEMs) were identified using the limma package in R, and the differentially methylated sites (DMSs) were identified using the ß distribution and two-sample t-tests. The Database for Annotation, Visualization and Integrated Discovery, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome were subsequently used to perform functional and pathway enrichment analysis. The miRNA target genes were predicted using the online databases miRWalk. The protein-protein interactions (PPI) were analyzed using the Search Tool for the Retrieval of Interacting Genes/Proteins. The regulatory network was constructed, and the gene expression and methylation levels of the key nodes were detected using reverse-transcription quantitative-polymerase chain reaction (PCR) and methylation-specific PCR. A total of 155 overlapping DEGs were identified between the GSE97001 and GSE83520 datasets, and 19 DEMs between PTC tissue and normal tissue samples were identified in the GSE73182 set. In the GSE86961 and GSE97466 datasets, 2,910 overlapping DMSs that were associated with 38 downregulated methylated genes were identified. The overlapping DEGs were enriched in 46 Gene Ontology terms and one KEGG pathway. A total of 60 PPI pairs were identified for the overlapping DEGs and 12 negative miRNA-gene pairs were identified for the DEMs. The expression levels of hsa-miR-199a-5p and decorin (DCN) were decreased in patients with PTC. C-X-C motif chemokine ligand 12 (CXCL12) was hypermethylated and had a decreased expression level in PTC tissues. LDL receptor related protein 4 (LRP4) and carbonic anhydrase 12 (CA12) were hypomethylated and had an increased expression level. The present study revealed that hsa-miR-199a-5p, DCN, CXCL12, LRP4 and CA12 may serve important roles in the pathogenesis of PTC.

High expression of NUCB2 promotes papillary thyroid cancer cells proliferation and invasion.

BACKGROUND: NUCB2, a novel multifunctional protein containing several functional domains, was newly found to play important roles in many cancers, but its role in papillary thyroid cancer (PTC) is not well investigated. Therefore, our study was performed to explore the functions of NUCB2 in PTC. METHODS: NUCB2 protein level was analyzed by immunohistochemistry. Data analyses were made by performing chi-squared test. Quantitative reverse-transcription PCR, Western blot, colony formation, MTT, and transwell invasion assays were performed to test the expression levels and functions of NUCB2 in PTC. RESULTS: In PTC tissues, NUCB2 protein expression level was positively correlated with extrathyroidal extension, TNM stage, and tumor size of PTC patients. In vitro experiments demonstrated that knockdown of NUCB2 using specific shRNA for NUCB2 significantly impaired cell proliferation and invasion of PTC cell lines. In vivo, silencing of NUCB2 inhibited the growth of tumors in mice. CONCLUSION: These results suggested a novel function of NUCB2 in the process of proliferation and invasion in PTC. NUCB2 may be considered a potent prognostic factor in PTC.

Targeting histone methyltransferase G9a inhibits growth and Wnt signaling pathway by epigenetically regulating HP1α and APC2 gene expression in non-small cell lung cancer.

BACKGROUND: Dysregulated histone methyltransferase G9a may represent a potential cancer therapeutic target. The roles of G9a in tumorigenesis and therapeutics are not well understood in non-small cell lung cancer (NSCLC). Here we investigated the impact of G9a on tumor growth and signaling pathways in NSCLC. METHODS: Immunohistochemistry analyzed G9a expression in NSCLC tissues. Both siRNA and selective inhibitor were used to target G9a. The impact of targeting G9a on key genes, signaling pathways and growth were investigated in NSCLC cells by RNA sequencing analysis, rescue experiments, and xenograft models. RESULTS: Overexpression of G9a (≥ 5% of cancer cells showing positive staining) was found in 43.2% of 213 NSCLC tissues. Multiple tumor-associated genes including HP1α, APC2 are differentially expressed; and signaling pathways involved in cellular growth, adhesion, angiogenesis, hypoxia, apoptosis, and canonical Wnt signaling pathways are significantly altered in A549, H1299, and H1975 cells upon G9a knockdown. Additionally, targeting G9a by siRNA-mediated knockdown or by a selective G9a inhibitor UNC0638 significantly inhibited tumor growth, and dramatically suppressed Wnt signaling pathway in vitro and in vivo. Furthermore, we showed that treatment with UNC0638 restores the expression of APC2 expression in these cells through promoter demethylation. Restoring HP1α and silencing APC2 respectively attenuated the inhibitory effects on cell proliferation and Wnt signaling pathway in cancer cells in which G9a was silenced or suppressed. CONCLUSIONS: These findings demonstrate that overexpressed G9a represents a promising therapeutic target, and targeting G9a potentially suppresses growth and Wnt signaling pathway partially through down-regulating HP1α and epigenetically restoring these tumor suppressors such as APC2 that are silenced in NSCLC.

Triptolide inhibits Wnt signaling in NSCLC through upregulation of multiple Wnt inhibitory factors via epigenetic modifications to Histone H3.

In the last decade, it has become clear that epigenetic changes act together with genetic mutations to promote virtually every stage of tumorigenesis and cancer progression. This knowledge has triggered searches for "epigenetic drugs" that can be developed into new cancer therapies. Here we report that triptolide reduced lung cancer incidence from 70% to 10% in a Fen1 E160D transgenic mouse model and effectively inhibited cancer growth and metastasis in A549 and H460 mouse xenografts. We found that triptolide induced lung cancer cell apoptosis that was associated with global epigenetic changes to histone 3 (H3). These global epigenetic changes in H3 are correlated with an increase in protein expression of five Wnt inhibitory factors that include WIF1, FRZB, SFRP1, ENY2, and DKK1. Triptolide had no effect on DNA methylation status at any of the CpG islands located in the promoter regions of all five Wnt inhibitory factors. Wnt expression is implicated in promoting the development and progression of many lung cancers. Because of this, the potential to target Wnt signaling with drugs that induce epigenetic modifications provides a new avenue for developing novel therapies for patients with these tumor types.

Targeting USP22 Suppresses Tumorigenicity and Enhances Cisplatin Sensitivity Through ALDH1A3 Downregulation in Cancer-Initiating Cells from Lung Adenocarcinoma.

Loss of monoubiquitination of histone H2B (H2Bub1) was found to be associated with poor-differentiation and enhanced malignancy of lung adenocarcinoma. This study investigated the association and impact of the ubiquitin-specific peptidase 22 (USP22), an H2Bub1 deubiquitinase, on stem cell-like characteristics and cisplatin resistance in cancer-initiating cells (CIC) from primary lung adenocarcinoma. CICs were isolated, enriched, and characterized from patient-derived cancer tissues using both in vitro tumorsphere formation and in vivo xenograft assays. USP22 was determined to be predominantly expressed in CICs, a subpopulation of cells with high expression of the stem cell biomarkers, CD133 and CD44. The expression of USP22 in CICs is markedly reduced upon FBS/retinoic acid-induced differentiation. Moreover, knockdown of USP22 significantly suppressed tumorsphere formation and xenograft growth in NOD-SCID gamma (NSG) mice. Notably, USP22 and aldehyde dehydrogenase (ALDH) activity were elevated in tumorsphere cells that survived cisplatin treatment, whereas knockdown of USP22 significantly sensitizes tumorsphere cells to cisplatin. Interestingly, ALDH1A3, a predominant ALDH isozyme implicated in enhancing cisplatin resistance in lung adenocarcinoma, is significantly downregulated upon knockdown of USP22 in tumorsphere cells. Furthermore, knockdown of ALDH1A3 significantly sensitizes tumorsphere cells to cisplatin. Combined, these data demonstrate that USP22, predominantly expressed in CD133+ CICs, plays a critical role in tumorigenicity and cisplatin resistance in lung adenocarcinoma.Implications: Targeting USP22 represents a potential therapeutic approach to suppress CICs in lung adenocarcinoma partially through downregulation of ALDH1A3 expression. Mol Cancer Res; 16(7); 1161-71. ©2018 AACR.

Overexpression of Flap Endonuclease 1 Correlates with Enhanced Proliferation and Poor Prognosis of Non-Small-Cell Lung Cancer.

Flap endonuclease 1 (FEN1) plays a crucial role in both DNA replication and damage repair. In this study, FEN1 expression and its clinical-pathologic significance in non-small-cell lung cancer (NSCLC) was investigated. Quantitative RT-PCR and immunohistochemistry analysis identified that both FEN1 mRNA and protein were highly overexpressed in about 36% of 136 cancer tissues compared to adjacent tissues, in which FEN1 was generally undetectable. Notably, patients with FEN1-overexpressed cancers were prone to have poor differentiation and poor prognosis. A strong positive correlation between the levels of FEN1 and Ki-67 staining was identified in these NSCLC tissues (r = 0.485), suggesting overexpressed FEN1 conferred a proliferative advantage to NSCLC. Furthermore, knockdown of FEN1 resulted in G1/S or G2/M phase cell cycle arrest and suppressed in vitro cellular proliferation in NSCLC cancer cells. Consistently, a selective FEN1 inhibitor was shown to effectively inhibit cellular proliferation of NSCLC cells in a dose-dependent manner. Additionally, knockdown of FEN1 significantly attenuated homologous DNA repair efficiency and enhanced cytotoxic effects of cisplatin in NSCLC cells. Taken together, these findings have indicated that overexpressed FEN1 represents a prognostic biomarker and potential therapeutic target for NSCLC treatment, which warrants further study.

Loss of H2B monoubiquitination is associated with poor-differentiation and enhanced malignancy of lung adenocarcinoma.

Deregulated monoubiquitination of histone H2B (H2Bub1), mainly catalyzed by E3 ubiquitin-protein ligase RNF20/RNF40 complex, may play an important role in cancer. Here we investigate potential roles of H2Bub1 and the underlying mechanisms through which it contributes to cancer development and progression in lung adenocarcinoma. We show that downregulation of H2Bub1 through RNF20 knockdown dramatically decreases H3K79 and H3K4 trimethylation in both normal and malignant lung epithelial cell lines. Concurrently, global transcriptional profiling analysis reveals that multiple tumor-associated genes such as CCND3, E2F1/2, HOXA1, Bcl2 modifying factor (BMF), Met, and Myc; and signaling pathways of cellular dedifferentiation, proliferation, adhesion, survival including p53, cadherin, Myc, and anti-apoptotic pathways are differentially expressed or significantly altered in these lung epithelial cells upon downregulation of H2Bub1. Moreover, RNF20 knockdown dramatically suppresses terminal squamous differentiation of cultured bronchial epithelial cells, and significantly enhances proliferation, migration, invasion, and cisplatin resistance of lung cancer cells. Furthermore, immunohistochemistry analysis shows that H2Bub1 is extremely low or undetectable in >70% of 170 lung adenocarcinoma samples. Notably, statistical analysis demonstrates that loss of H2Bub1 is significantly correlated with poor differentiation in lung adenocarcinoma (p = 0.0134). In addition, patients with H2Bub1-negative cancers had a trend towards shorter survival compared with patients with H2Bub1-positive cancers. Taken together, our findings suggest that loss of H2Bub1 may enhance malignancy and promote disease progression in lung adenocarcinoma probably through modulating multiple cancer signaling pathways.

miR-24 promotes the proliferation, migration and invasion in human tongue squamous cell carcinoma by targeting FBXW7.

Recent studies suggest that aberrant expression of miR-24 is linked to various human cancers, including tongue squamous cell carcinoma (TSCC). F-box and WD-40 domain protein 7 (FBXW7), a tumor-suppressor gene, is responsible for the degradation of several proto-oncogenes. However, the function and mechanism of miR-24 and FBXW7 in TSCC remains unclear. In the present study, we found that miR-24 was increased in TSCC tissues and cell lines, and that upregulation of miR-24 was associated with advanced clinical stage and a shorter overall survival of TSCC patients. Inhibition of miR-24 significantly suppressed the proliferation, migration and invasion of TSCC cells in vitro. Furthermore, miR-24 repressed FBXW7 expression by directly binding to the 3-untranslated region of FBXW7. Moreover, the suppression of FBXW7 increased the proliferation, migration and invasion of TSCC cells, and the restoration of FBXW7 substantially attenuated the oncogenic effects of miR-24. In conclusion, our results demonstrated that upregulation of miR-24 was associated with tumor progression and poor prognosis in TSCC patients, and that overexpression of miR-24 was correlated with the proliferation, migration and invasion of TSCC cells in vitro, at least partially through regulation of its functional target FBXW7. Thus, miR-24 may serve as a novel potential biomarker for the prognosis of TSCC patients.

MicroRNA-24 induces cisplatin resistance by targeting PTEN in human tongue squamous cell carcinoma.

BACKGROUND: miR-24 is one of the most significantly up-regulated miRNAs in tongue squamous cell carcinoma (TSCC). PTEN plays an important role in the cell survival and cisplatin resistance of multiple cancers. However, it remains unclear what role does function and mechanism of miR-24 and PTEN play in TSCC. METHODOLOGY/PRINCIPAL FINDINGS: In this study, miR-24 expression was detected in 79 cases of paired TSCC and normal tissues and 8 TSCC cell lines by real-time PCR and the relevance between miR-24 expression and clinicopathological parameters were analyzed. Further, we demonstrated that deregulation of miR-24 was found to associate with high grade and late stage tumor. In addition, miR-24 induces cell survival and cisplatin resistance through targeting 3'-UTR region of the PTEN, which leads to downregulation of PTEN protein and activation of Akt pro-survival pathway. CONCLUSIONS/SIGNIFICANCE: In conclusion, our results demonstrated that deregulation of miR-24 is a recurrent event in human tongue squamous cell carcinoma and associate with tumor progression and that miR-24 induces cell survival and cisplatin resistance primarily through targeting PTEN/Akt pathway. Thus, miR-24 could be important targets for intervention of this malignancy.

[Angiosarcoma of the head and face: a retrospective study of 15 patients].

OBJECTIVE: To investigate the clinical and pathological characteristics of angiosarcoma of the head and face. METHODS: The data of 15 patients with angiosarcoma of the head and face underwent treatment between January 1993 and January 2003 were reviewed. Of 15 cases 10 were men and 5 women; 11 tumors in scalp and 4 in face; 6 cases of stage I, 3 cases of stage II, 1 case of stage III and 5 cases of stage IV. Clinical symptoms included a focal mass or bruiselike patches. Surgery alone in 5 cases, chemotherapy alone in 3 cases, comprehensive treatment in 5 cases, no treatment in 2 cases. Immunohistochemical staining with CD31, CD34 and FVIIIRag was performed in 8 cases. RESULTS: Follow-up time was 3-240 months with a median of 28 months. One patient of stage I by surgery alone and 2 patients of stage I with comprehensive treatment survived for 121, 209 and 240 months respectively and no recurrence. One patient of stage I with comprehensive treatment was survival for 127 months with tumor burden. Eleven cases died in 3-78 months after diagnosis, the median follow-up time was 20 months. Three year and five year survival rates were 46.7% and 33.3%, respectively. Immunohistochemical staining showed CD31- and CD34-positive for 8 cases and FVIIIRag-positive for 6 cases. CONCLUSIONS: Angiosarcoma of the head and face is a high-risk sarcoma. It is rare and easily misdiagnosed but can be diagnosed properly based on pathological feature. Comprehensive treatment including surgery, radiotherapy and chemotherapy can improve survival rate for the patients with early stage angiosarcoma.

Papillary microcarcinoma of the thyroid: clinical characteristics and BRAF(V600E) mutational status of 977 cases.

BACKGROUND: Papillary thyroid carcinoma (PTC) is one of the most common endocrine malignancies. It is estimated that papillary thyroid microcarcinoma (PTMC) accounts for up to 30 % of all PTCs. The clinical significance of PTMC is still unclear, although it may be related to recurrence, distant metastasis, and mortality. The purpose of this study was to analyze the clinical characteristics and BRAF(V600E) mutational status of PTMCs in a Chinese population and to determine risk factors for poor prognosis. METHODS: We performed a retrospective review of 977 PTMC cases that underwent surgical resection from January 2001 to January 2010 at Tianjin Medical University Cancer Institute and Hospital. RESULTS: The mean size of 977 PTMCs was 5.2 (range, 2-10) mm. Multifocal tumors were seen in 323 patients. The majority of patients (692) had a T1 lesion, whereas 279 had T3 and 6 had T4a; 40.1 % patients had BRAF(V600E) mutation. The frequencies of extrathyroidal extension and lymph node metastasis were 29.2 and 23.4 %, respectively. Distant metastasis was present in 15 patients. Half of the patients (50.8 %) received a total thyroidectomy and others had a lobectomy. CONCLUSIONS: The present study suggests that highly aggressive PTMCs may arise in a subset of patients with BRAF(V600E) mutation and tumors greater than 5 mm. Extrathyroidal invasion, lymph node metastases, and the type of surgical procedures were significantly associated with tumor recurrence. Although multivariate analysis showed that tumor recurrence was not associated with BRAF(V600E) mutation, it has not been shown that treating these patients more aggressively changes outcomes.

Progression of solitary and multifocal papillary thyroid carcinoma - a retrospective study of 368 patients.

BACKGROUND: Papillary thyroid carcinoma (PTC) represents one of the most frequent endocrine malignancies. Several factors have been found to be involved in determining the outcome of treatment for patients with PTC. Large tumor size, diagnosis at an early age, extra-thyroidal invasion, aggressive histological variants, and distant metastases are the most important determinants of a poor outcome. BRAF(V600E) mutation has been found to be a major genetic alteration in PTC. This study aimed to evaluate progression in patients with multifocal and solitary PTC. METHODS: We performed a retrospective study to analyze 368 patients with PTC who underwent surgery, including 282 patients with solitary PTC and 86 patients with multifocal PTC. The status of BRAF(V600E) mutation in all tumor foci from multifocal PTC was detected. RESULTS: Our study suggested that multifocal PTC was more related to lymph node metastasis and vascular invasion than solitary PTC. However, the distant metastasis rate and 10-year survival rate showed no difference between these two groups. The number of tumor foci did not affect progression of disease in multifocal PTC patients. Lymph node metastasis in multifocal PTC patients was associated with larger tumors, diagnosis at early stage, and extra-thyroidal invasion. CONCLUSION: The status of BRAF(V600E) mutation was more frequent in multifocal PTC patients with lymph node metastasis and diagnosis at later age.