Zhong Wu Lu

BRAF-activated LncRNA functions as a tumor suppressor in papillary thyroid cancer

Long non-coding RNAs (lncRNAs) participate in cancer cell tumorigenesis, cell cycle control, migration, proliferation, apoptosis, metastasis and drug resistance. The BRAF-activated non-coding RNA (BANCR) functions as both an oncogene and a tumor suppressor. Here, we investigated BANCRs role in papillary thyroid carcinoma (PTC) by assessing BANCR levels in PTC and matched normal thyroid epithelial tissues from 92 patients using qRT-PCR. We also used lentiviral vectors to establish PTC cell lines to investigate the effects of BANCR overexpression on cancer cell proliferation, apoptosis, migration and invasion. Our results indicate BANCR levels are lower in PTC tumor tissues than control tissues. Decreased BANCR levels correlate with tumor size, the presence of multifocal lesions and advanced PTC stage. BANCR overexpression reduced PTC cell proliferation and promoted apoptosis, which inhibited metastasis. It also inactivated ERK1/2 and p38, and this effect was enhanced by treatment with the MEK inhibitor U0126. Finally, BANCR overexpression dramatically inhibited tumor growth from PTC cells in xenograft mouse models. These results suggest BANCR inhibits tumorigenesis in PTC and that BANCR levels may be used as a novel prognostic marker.

Association of the miR-149 Rs2292832 Polymorphism with Papillary Thyroid Cancer Risk and Clinicopathologic Characteristics in a Chinese Population

(1) Background: The genetic predisposition to papillary thyroid cancer (PTC) is far from clearly elucidated. Rs2292832 is a genetic polymorphism that located in the precursor of mir-149 and has been studied in diverse cancers. Thus far, the role of rs2292832 in PTC tumorigenesis and progression was unclear; (2) Method: Rs2292832 was genotyped in 838 PTCs, 495 patients with thyroid benign tumors (BNs) and 1006 controls in a Chinese Han population. Clinicopathological data was collected and compared. The expression level of mature mir-149 was examined in 55 normal thyroid tissue samples; (3) Results: The CC genotype of rs2292832 was significantly associated with an increased risk of PTC compared with TT homozygote (OR = 1.60, 95% CI: 1.72–2.20, p = 0.003) and TT/TC combined genotype (OR = 1.54, 95% CI: 1.14–2.09, p = 0.005). Rs2292832 is an independent risk factor correlated with tumor invasion (p = 0.006) and higher T stage in PTC patients (p = 0.007), but uncorrelated with short-term disease persistence of PTC. PTC subjects carrying CC genotype have lower mir-149-5p expression than those with TC genotype (p = 0.002). Twelve predicted target genes have been identified by collaboratively using computational tools; (4) Conclusion: Rs2292832 was possibly involved in the susceptibility and local progression of PTC in Chinese patients, by altering the expression level of mir-149-5p and its target genes.

Predictive index for lymph node management of major salivary gland cancer

To find the risk factors of lymph node (LN) metastasis of salivary gland cancer and draw a scheme for LN management.

The impact of marital status at diagnosis on cancer survival in patients with differentiated thyroid cancer

Previous studies have revealed that marital status influences the prognosis of patients with various types of cancer. We evaluated the influence of marriage on the survival outcomes in differentiated thyroid cancer (DTC). The Surveillance, Epidemiology and End Results (SEER) database between 2002 and 2012 was used to compare cancer‐specific mortality in different marital status, and in each sex, age, and stage stratification by multivariate Cox regression model. In total, 61,077 eligible patients were identified. The widowed group had the highest proportion of women, elderly patients (≥45 years), and advanced stage III/IV tumor (P = 0.001), but the total thyroidectomy (TT) performed and radioisotopes therapy rates were lower than those in the married group. Married patients had a better cancer‐specific survival (CSS) than the unmarried (P < 0.05). Further analysis showed that widowed patients always presented the lowest CSS compared with other groups. Widowed patients had a significant increased risk for CSS compared with married patients in males [hazard ratio (HR) 2.72, 95% confidence interval (CI): 1.59–4.65, P = 0.001], females (HR 2.02, 95% CI: 2.24–4.06, P = 0.001), young patients (<45, HR 28.12, 95% CI: 3.48–227.25, P = 0.002), elderly patients (≥45, HR 28.12, 95% CI: 2.97, 95% CI: 2.30–3.83, P = 0.001), stage I (HR 8.44, 95% CI: 4.05–17.59, P = 0.001), stage II (HR 3.64, 95% CI: 1.30–10.20, P = 0.014), stage III (HR 2.27, 95% CI: 1.08–4.78, P = 0.031), and stage IV (HR 2.63, 95% CI: 1.94–3.57, P = 0.001). These results showed that unmarried status, especially for widowhood, increased the risk of cancer mortality in DTC patients.

The chemokine receptor-CXCR2 plays a critical role in the invasion and metastases of oral squamous cell carcinoma in vitro and in vivo.

BACKGROUND Oral squamous cell carcinoma (OSCC) is one of the most common cancers in the world with about 50% survival rate over 5 years. OSCC has a highly invasive potency and frequently metastasizes to the cervical lymph nodes, which is the principle reason leading to poor prognosis. CXCR2, the receptor of CXC chemokines, has been reported to be involved in invasion and metastasis in multiple types of malignancy. However, the accurate role of CXCR2 in OSCC has been little noticed. METHODS In this study, we determined the expression of CXCR2 in OSCC using immunohistochemical staining (IHC) and analyzed the association between the expression of CXCR2 and the biobehavior of OSCC. Then, we established stable OSCC cell lines with interference of CXCR2 and observed the effect of CXCR2 knockdown on cell proliferation, migration, invasion, and morphological changes in vitro and in vivo. RESULTS CXCR2 was positively expressed in 55.3% of OSCC patients and was statistically associated with the high cervical lymph node metastasis in OSCC. CXCR2 silencing markedly inhibited migration and invasion of OSCC cells in vitro and in vivo. Moreover, CXCR2 silencing led to morphological changes and decreased lamellipodial structures in OSCC cells. However, CXCR2 silencing showed no effect on proliferation of OSCC cells in vitro and in vivo. CONCLUSIONS CXCR2 plays a critical role in the invasion and metastases of OSCC. And it is probably by regulating actin cytoskeletal remodeling that CXCR2 takes part in the invasion and metastases of OSCC.

Clinical significance of papillary thyroid cancer risk loci identified by genome-wide association studies

Four single nucleotide polymorphisms (SNPs) have been reported to be associated with thyroid cancer risk in two genome-wide association studies (GWASs) and were validated in a Chinese population. Because of a lack of further clinical and functional evidence, the clinical significances of these SNPs remain unknown. Four GWAS-identified SNPs of papillary thyroid cancer (PTC), rs965513, rs944289, rs966423 and rs2439302, were genotyped in a case-control study of 838 patients with PTC and 501 patients with benign thyroid tumor (BTT) from the Chinese Han population. The associations between these SNPs, clinicopathologic features, and the outcome of the PTC patients were examined. The CT and CT + TT genotypes of rs966423 were more common in PTC patients with extrathyroidal extension and more advanced T stage. The TC and TC + CC genotypes and the C allele of rs944289 were significantly less frequent in patients with multifocal disease. No correlation was observed between GWAS-identified SNPs and disease persistence of PTC after a short-term follow-up. Significantly different allele distributions between the PTC and BTT groups were observed for all four selected SNPs. Individuals with more than five risk alleles were 8.84-fold (95% CI 3.23-24.17) more likely to suffer from PTC compared with those with zero or 1 risk allele. GWAS-identified SNPs affect the individual predisposition to PTC without interacting with existing Hashimoto thyroiditis and BTT lesions. GWAS-identified SNPs were associated with certain clinicopathologic features of PTC, and may contribute to identifying PTC patients with different clinical patterns. Large prospective studies are required to further evaluate the diagnostic and prognostic power of these genetic markers.

Metastatic lymph node ratio can further stratify risk for mortality in medullary thyroid cancer patients: A population-based analysis

Medullary thyroid cancer (MTC) has a propensity to cervical lymph node metastases (LNM). Recent studies have shown that both the number of involved lymph nodes (LNs) and the metastatic lymph node ratio (MLNR) confer prognostic information. This study was to determine the predictive value of MLNR on cancer-specific survival (CSS) in SEER (Surveillance, Epidemiology and End Results)-registered MTC patients treated with thyroidectomy and lymphadenectomy between 1991 and 2012, investigate the cutoff points for MLNR in stratifying risk of mortality and provide evidence for selection of appropriate treatment strategies. X-tile program determined 0.5 as optimal cut-off value for MLNR in terms of CSS in 890 MTC patients. According to multivariate Cox regression analysis, MLNR (0.50–1.00) is a significant independent prognostic factor for CSS (hazard ratio 2.161, 95% confidence interval 1.327–3.519, p=0.002). MLNR (0.50–1.00) has a greater prognostic impact on CSS in female, non-Hispanic white, T3/4, N1b and M1 patients. The lymph node yield (LNY) influences the effect of MLNR on CSS; LNY ≥9 results in MLNR (0.50–1.00) having a higher HR for CSS than MLNR (0.00-0.49). In conclusion, higher MLNRs predict poorer survival in MTC patients. Eradication of involved nodes ensures accurate staging and maximizes the ability of MLNR to predict prognosis.

Tumor size interpretation for predicting cervical lymph node metastasis using a differentiated thyroid cancer risk model

Lymph node metastasis (LNM) is common in differentiated thyroid cancer (DTC), but management of clinically negative DTC is controversial. This study evaluated primary tumor size as a predictor of LNM. Multivariate logistic regression analysis was used for DTC patients who were treated with surgery between 2002 and 2012 in the Surveillance, Epidemiology, and End Results (SEER) database, to determine the association of tumor size at 10 mm increments with LNM. A predictive model was then developed to estimate the risk of LNM in DTC, using tumor size and other clinicopathological characteristics identified from the multivariate analysis. We identified 80,565 eligible patients with DTC in the SEER database. Final histology confirmed 9,896 (12.3%) cases affected with N1a disease and 8,194 (10.2%) cases with N1b disease. After the patients were classified into subgroups by tumor size, we found that the percentages of male sex, white race, follicular histology, gross extrathyroidal extension, lateral lymph node metastasis, and distant metastasis gradually increased with size. In multivariate analysis, tumor size was a significant independent prognostic factor for LNM; in particular, the odds ratio for lateral lymph node metastasis continued to increase by size relative to a 1–10 mm baseline. The coefficient for tumor size in the LNM predictive model waŝ0.20, indicating extra change in log(odds ratio) for LNM as 0.2 per unit increment in size relative to baseline. In conclusion, larger tumors are likely to have aggressive features and metastasize to a cervical compartment. Multistratification by size could provide more precise estimates of the likelihood of LNM before surgery.

Risk prediction and clinical model building for lymph node metastasis in papillary thyroid microcarcinoma

The surgical management of papillary thyroid microcarcinoma (PTMC), especially regarding the necessity of central/lateral lymph node dissection, remains controversial. This study investigated the clinicopathologic factors predictive of lymph node metastasis (LNM) in patients diagnosed with PTMC. Multivariate logistic regression analysis was used for PTMC patients identified from the Surveillance, Epidemiology, and End Results database who were treated by surgery between 2002 and 2012, to determine the association of clinicopathologic factors with LNM. According to the results, a total of 31,017 patients met the inclusion criteria of the study. Final histology confirmed 2,135 (6.9%) cases of N1a disease and 1,684 cases (5.4%) of N1b disease. Our multivariate logistic regression analysis identified variables associated with both central LNM and lateral lymph node metastasis (LLNM), including a younger age (<45 years), male sex, non-Hispanic white and other race, classical papillary histology, larger tumor size, multifocality, and extrathyroidal extension; distant metastasis was also significantly associated with LLNM. The significant predictors identified from multivariable logistic regression were integrated into a statistical model that showed that extrathyroidal extension had maximum weight in the predictive role for LNM. LLNM was validated to be a significant risk factor for cancer-specific death in Cox regression analyses, whereas central LNM failed to predict a worse cancer-specific survival according to our data. Therefore, we suggested that central lymph node dissection could be performed in certain patients with risk factors. Given the prevalence of LLNM in PTMC, a thorough inspection of the lateral compartment is recommended in PTMC patients with risk factors for precise staging; from the viewpoint of a radical treatment for tumors, prophylactic lateral lymph node dissection that aims to remove the occult lateral lymph nodes may be an option for PTMC with risk factors. Multicenter studies with long-term follow-up are recommended to better understand the risk factors and surgical management for cervical nodes in PTMC.