Papillary thyroid cancer (PTC) is the most common subtype of thyroid cancer, which accounts for 80-90% of all thyroid cancer cases. Though the pathological mechanism hasn't been fully understood, it is reported that both environmental and genetic factor may contribute to the PTC susceptibility. MicroRNAs (miRNAs) are small non-coding RNA molecules which function as the suppressors to participate in a variety of biological processes. Accumulating evidence suggests that polymorphisms of miRNAs were associated with the tumorigenesis of various cancers, including PTC. In this article, we focus on the association between four common microRNA polymorphisms (miR-146a, miR-608, miR-933, and miR-149) and PTC risk in a Han Chinese population.

Gastric cancer (GC) is one of the most common malignancies and one of the major causes of cancer-related deaths worldwide. In the present study, we investigated the association between miR-449a rs112310158 SNP and GC risk. Our findings revealed that a variant GG genotype increased the risk of occurrence of GC compared to a wild type AA genotype (OR = 2.542, 95% CI: 1.304-4.954, P = 0.005). Specifically, the G allele reduced the risk of occurrence of cervical cancer in women compared to the A allele (OR = 1.279, 95% CI: 1.012-1.617, P = 0.043). In conclusion, our findings suggest that miR-449a rs112310158 is a genetic risk factor for GC.

We conducted a prospective study to analyze whether six SNPs in ERCC1 gene could serve as potential biomarkers for prognosis of gastric cancer. Between January 2010 and December 2012, 270 patients with pathologically proven gastric cancer and receiving platinum-based chemotherapy were recruited in our study. Genotyping of the ERCC1 rs11615, rs2298881, rs3212955, rs3212961, rs3212986 and rs735482 were carried out using the Sequenom MassARRAY platform. By logistic regression analysis, patients carrying the GT and TT genotypes of rs3212986 showed a significantly poorer response to chemotherapy than did those carrying the GG genotype, and the ORs (95% CI) were 0.47 (0.25-0.88) and 0.18 (0.08-0.41), respectively. By Cox proportional hazards models, the GT and TT genotypes of rs3212986 were correlated with increased risk of death when compared with the GG genotype, and the adjusted HRs (95% CIs) were 1.79 (1.01-3.16) and 2.57 (1.18-5.62), respectively. However, we did not find significant association between ERCC1 rs11615, rs2298881, rs3212955, rs3212961 and rs735482 and response to chemotherapy and overall survival in patients with gastric cancer. In conclusion, the results of the present retrospective study indicate that there is a significant difference in biological behavior between ERCC1 rs3212986 gene polymorphism and treatment outcome of gastric cancer.

PIK3CA has been shown to be involved in many malignant tumors. This study was designed to determine the expression level of PIK3CA in oral squamous cell carcinoma (OSCC) and the association of gene polymorphisms of PIK3CA with OSCC in Chinese population. The expression of PIK3CA was detected by real-time PCR in tumor and pericarcinomatous tissues of 10 OSCC patients. Nine single-nucleotide polymorphisms (SNPs) of PIK3CA (rs1607237, rs17849079, rs2677764, rs2699887, rs4855094, rs4975596, rs6443624, rs7651265 and rs7736074) in blood of 113 OSCC patients and 184 normal controls were genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) assay. The gene expression of PIK3CA was significantly higher in tumor tissues of OSCC patients than that in pericarcinomatous tissues (P = 0.012). An increased frequency of the C allele of PIK3CA rs1607237 was observed in OSCC patients as compared with controls; However, the significance was lost after Bonferroni correction (P = 0.048, pc = 0.576). In further stratification analysis, although the frequencies of PIK3CA rs4975596 A allele in male patients and rs1607237 C allele in female patients were increased (P = 0.032, P = 0.020, respectively), the significance was also missing when Bonferroni correction was performed (P c = 0.384, (P c = 0.24, respectively). The prevalence of other SNPs of PIK3CA did not differ between OSCC patients and controls. The expression of PIK3CA was increased in OSCC tumors; however, none of the nine tested SNPs of PIK3CA was associated with susceptibility to OSCC in the studied population.

The clinical relevance of frizzled-related protein (FRZB) in hepatocellular carcinoma (HCC) bone metastasis remains uncertain. The aim of this study was to assess the clinical relationship of FRZB in patients with HCC bone metastasis after surgical resection. FRZB expression was evaluated by immunohistochemistry in formalin-fixed paraffin embedded (FFPE) HCC and paired bone metastasis tissues from 13 patients that underwent surgical resection. The clinical characteristics of 13 HCC patients with synchronous or metachronous bone metastasis received surgery were retrospectively reviewed. We found that FRZB was positive in 9 HCC tissues (69.2%) and in 11 paired bone metastatic tissues (84.6%) among these 13 paired samples. The expression of FRZB in the bone metastases was noticeably higher than that in the paired HCC tissues. The expression of FRZB was up-regulated in 10 (76.9%) paired bone metastases tissues. FRZB expression was up-regulated in HCC bone metastasis tissue, which suggested that FRZB might play a key role in the HCC bone metastasis.

We evaluated the association of GSTM1 null/present, GSTT1 null/present, and GSTP1 IIe105Val polymorphisms with the clinical response to chemotherapy and treatment outcome of NSCLC. Between October 2009 and October 2012, a total of 282 patients with advanced NSCLC were enrolled into our study, and they were followed up until October 2014. The genotypes of GSTM1, GSTT1, and GSTP1 IIe105Val were performed by polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP). By logistic regression analysis, our study found that the Val/Val genotype of GSTP1 IIe105Val was associated with more CR+PR response to chemotherapy when compared with the IIe/IIe genotype, and the OR (95% CI) was 2.18 (1.16-4.12). By multivariate Cox proportional hazards regression analysis, we found the Val/Val genotype of GSTP1 was correlated with lower risk of death in advanced NSCLC (HR, 0.48; 95% CI, 0.25-0.93). However, no association was found between GSTT1 and GSTM1 polymorphisms and response to chemotherapy and overall survival of advanced NSCLC. Moreover, the IIe/Val + Val/Val genotypes of GSTP1 were associated with lower risk of death in never smokers, and the adjusted HR (95% CI) was 0.34 (0.12-0.93). In conclusion, we found that the GSTP1 polymorphism was correlated with better response to chemotherapy and lower risk of death in advanced NSCLC patients.

The genetic or abnormal activation of PI3K/PTEN signaling pathway play an important role with regard to disease progression in variety of human malignancies. Experimental and epidemiologic studies indicated that the genetic polymorphisms in the PTEN, PI3K genes are associated with cancer risk, yet little evidence exists for those 2 genes and colorectal cancer (CRC) risk. To address this, we evaluated whether PTEN rs701848, PIK3CA rs2699887 variants are associated with CRC susceptibility, clinicopathological parameters and clinical outcomes in CRC patients treated with FOLFOX (Oxaliplatin, Leucovorin, 5-Fluorouracil) regimen. A case-control study was performed in 780 CRC patients and 764 healthy controls using the TaqMan assay method. A significant increased risk of CRC was observed in patients carrying PTEN rs701848 TC or CC genotype (adjusted OR=1.306, 95% CI=1.030-1.655, P=0.027; adjusted OR=1.543, 95% CI=1.148-2.075, P=0.004, respectively), TC/CC genotype (adjusted OR=1.367, 95% CI=1.090-1.714, P=0.043) in the dominant model, and C allele (adjusted OR=1.229, 95% CI=1.067-1.416, P=0.004). However, no association was detected between rs2699887 in the PIK3CA gene and CRC risk. A significant association was found between pathological grade (Dukes A and B vs. Dukes C and D) and PIK3CA rs2699887 genotypes. Furthermore, Kaplan-Meier analysis revealed that PTEN rs701848 genotypes were significantly associated with the overall survival (OS) of CRC patients treated with FOLFOX regimen (n=780). Individuals carrying PTEN rs701848 TC or TC/CC genotypes showed significantly longer median survival time (MST) than TT genotype and significant hazard ratio (TC: adjusted HR=0.523, 95% CI=0.325-0.840, P=0.007;

Gemcitabine (GEM) is the first-line chemotherapy in patients with unresectable pancreatic cancer. However, the clinical outcomes of this regimen are still unsatisfactory in prolonging survival. Resistant to GEM is one of the reasons for poor prognosis. Therefore, looking for molecular biomarkers to predict chemosensitivity to GEM is important for treatment in unresectable pancreatic cancer patients. The aim of this study was to analyze S100A4 mRNA in tissues of unresectable pancreatic cancer obtained by endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA), and to determine the relation between S100A4 mRNA level and chemosensitivity to GEM.

Survivin, a member of the inhibitor of apoptosis gene family regulates two critical processes in neoplastic transformation, namely, cell proliferation and apoptosis. This study aimed to detect the effect of survivin on tumor growth of colorectal cancer (CRC) in vivo. We found that inhibition of survivin by interference decreased the sizes and weights of xenografts in nude mice. The number of apoptotic cells of the shRNA survivin group was higher than that of the black group and the shRNA control group. The downregulated expression of survivin decreased the expression levels of bcl2 and ki67. Our results indicated that inhibition of survivin significantly enhanced the inhibition of tumor growth and induced apoptosis. Survivin is an attractive target for CRC treatment.

Dysregulation of long non-coding RNAs (lncRNAs) plays critical roles in tumor progression. The purpose of this study was to investigate the relationship between lncRNA CCAT2 expression and cervical squamous cell cancer susceptibility and prognosis.

MicroRNAs (miRNAs or miRs) are a class of small, non-coding RNAs that can regulate the gene expression in various diseases. MicroRNA-203 (miRNA-203 or miR-203) has previously shown significant alteration in a number of cancers. However, the clinical value of miR-203 in melanoma is rarely reported. The present study aimed to clarify the expression pattern and prognostic role of miR-203 in melanoma patients. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to characterize the expression level of miR-203 in 148 cases of melanoma tissues and adjacent non-cancerous tissues. Results showed that miR-203 expression was significantly decreased in melanoma tissues compared with that in adjacent non-cancerous tissues (P<0.05). Additionally, chi-square was performed to analyze the relationship between miR-203 and clinicopathological features and the down-regulation of miR-203 was significantly associated with tumor thickness and tumor stage (P<0.05). Moreover, Kaplan-Meier analysis showed that low miR-203 expression was associated with short overall survival time of patients. Multivariate analysis indicated that miR-203 could be an independent prognostic marker (P=0.003, HR=2.851, 95% CI=1.439-5.650) in melanoma This study for the first time provided evidence that miR-203 could be an independent potential prognostic marker for patients with melanoma, and might even become a new therapeutic target for the treatment of melanoma.

The aims were to compare the consistency of epidermal growth factor receptor (EGFR) mutations in the plasma and tumor tissue of NSCLC patients, and to explore the prognostic significance of plasma EGFR mutation status in tyrosine kinase inhibitors (TKIs)-treated patients with tumor EGFR mutation.

Gastric cancer pathogenesis is a multi-factor, multi-step, complicated process that related to gene abnormal expression. This study intended to explore the miR-340 effect on human gastric cancer cell line SGC-7901 and BGG823 proliferation and apoptosis, as to provide theoretical basis and experimental evidence for potential clinical application. Array was used to screen gastric cancer related abnormal genes. Q-PCR was applied to detect the screened genes expression in tissue and gastric cancer cells. MTT and colony formation assay were performed to evaluate miR-340 impact on gastric cancer proliferation. Flow cytometry was used to determine cell cycle and cell apoptosis. Q-PCR showed that miR-340 overexpressed in gastric cancer tissue significantly compared with normal control (P < 0.01). MiR-340 overexpression can promote SGC-7901 and BGC823 cells proliferation with 50% proliferation rate. Soft agar colony formation assay also showed that miR-340 overexpression can facilitate gastric cancer cell proliferation. Cell cycle analysis revealed that miR-340 overexpression can reduce cell apoptosis. Annexin V/PI staining demonstrated that miR-340 transfection can decrease cell apoptotic rate (4.58%, 1.98%, 2.11%). MiR-340 can promote tumor cell growth and reduce cell apoptosis effectively.

As one of the most common malignant tumors, gastric cancer still lacks tumor markers with enough specificity and sensitivity. Therefore the development of novel tumor markers is necessary for early diagnosis in clinics. MicroRNA (miR) has been known to be of unique expressional patterns in various tumors and may work as potential tumor markers for clinical use. This study thus explored the significance of plasma miR-106a in clinical diagnosis of gastric cancer and its effects on proliferation of cancer cells. Plasma miR-106a levels were quantified by real-time quantitative fluorescent PCR methods in 80 cases of gastric cancer patients and healthy individuals to analyze the correlation between miR-106a and clinical features. MiR-106 inhibitor was further transfected into human gastric carcinoma cells for further cell proliferation using CCK-8 approach. MiR-106a was significantly up-regulated in gastric cancer patient plasma samples compared to healthy individuals (P<0.01). The area under ROC curve was 0.895 (95% CI: 0.846~0.943). It has a specificity of 93.8% and a sensitivity of 77.5% in diagnosing gastric cancer. MiR-106a level was also correlated with cancer differentiation stage, lymph node metastasis, TNM stage and tumor size (P<0.05). The down-regulation of miR-106 in gastric carcinoma cells inhibited cell proliferation (P<0.05). MiR-106a was significantly up-regulated in gastric cancer patients and can facilitate the in vitro proliferation of tumor cells. It may work as a biological marker for gastric cancer.

The tumor necrosis factor-α (TNF-α) gene, which plays crucial roles in tumorigenesis, is reported to be an independent marker for cancer. This study aims to examine the association between the TNF-α G308A polymorphism and DLBCL risk based on the two center case-control studies and meta-analysis.

To explore the relationship between death associated protein kinase (DAPK) gene promoter methylation and gefitinib resistance in Lung adenocarcinoma cell lines. EGFR-mutation lung adenocarcinoma cell lines PC9 and the gefitinib-resistant with T790M Mutation cell lines PC9/GR were chosen as cell models, and PC9/GR were treated with 5-aza-CdR (1 μmol/L). The experiments were divided into three groups: PC9 group, PC9/GR group and PC9/GR with 5-Aza-CdR pretreatment group. Treat three groups cell with different concentrations gefitinib, the cell proliferation was determined by MTT assay. The apoptotic rates were detected by flow cytometry. The methylation of DAPK gene promoter region was examined by methylation-specific PCR (MSP). The expressions of DAPK protein were detected by Western blot. MTT results showed that the half maximal inhibitory concentration (IC50) of PC9 and PC9/GR cell lines increase from 0.12 μmol/L to 8.52 μmol/L. But after treated with 5-aza-CdR, the IC50 of PC9/GR cell lines decrease to 4.35 μmol/L, and the resistance index (RI) decrease from 71 to 36 (P<0.05). Flow cytometry results showed that the apoptosis rate were 24.80% ± 0.28%, 12.70% ± 0.31%, 19.8% ± 0.15% respectively. MSP results showed that DAPK gene promoter region was un-methylated in PC9 cells and methylated in PC9/GR cells, when treated with 5-aza-CdR, DAPK gene promoter region was partly methylated in PC9/GR cells (P<0.05). Western blot results showed that the levels of DAPK protein were reduced significantly in PC9/GR cell lines compared with PC9, and after treated with 5-aza-CdR, the expression levels of DAPK protein in PC9/GR were increased (P<0.05). In conclusion, DAPK gene promoter methylation may contribute to the downregulation of DAPK gene and protein, and consequently affect the sensitivity of gefitinib in lung adenocarcinoma lines, induced gefitinib resistance. But 5-Aza-CdR can reverse gefitinib resistance by demethylation of DAPK gene promoter.

Hepatocellular carcinoma (HCC) is one of most common malignant tumors worldwide, but with unclear mechanisms. Xeroderma pigmentosum gene D (XPD) is one important DNA damage repair gene and can be involved in protein mutation. Currently little has been known about XPD polymorphism and HCC susceptibility in Chinese people. This study used a meta-analysis approach to comprehensively investigate the correlation between XPD polymorphism and HCC susceptibility in Chinese population, based on previously published literatures. A computer retrieval system was used to collect all case-control studies about XPD Lys751Gln polymorphism and HCC susceptibility. Data in literatures were extracted for meta-analysis. After the primary screening, four independent studies, which were published in 3 English articles and one Chinese article, were recruited in this study. There were 1,717 samples included in all studies. Using Gln/Gln + Lys/Gln, Lys/Lys + Lys/Gln and Lys allels as the reference, HCC disease alleles including Lys/Lys, Gln/Gln and Gln had OR values (95% CI, I(2)) of 1.007 (0.657~4.672, 91%), 3.516 (0.220~20.661, 48%) and 3.225 (0.278~12.326, 84%), respectively. The polymorphism of XPD751 loci is closely correlated with primary HCC. Lys751Gln polymorphism of XPD gene can be used as one susceptibility factor for HCC.

Gastric cancer (GC) is one of the most common malignancies and ranks the second leading cause of cancer death worldwide. The role of long non-coding RNAs (lncRNAs) in the gastric cancer pathogenesis is largely unknown. The present study is aimed to identify aberrantly expressed lncRNAs involved in the progression of GC. 33 lncRNAs showed significantly differential expression levels between gastric tumor samples and matched normal tissues from 5 pairs of samples using microarray assay. LncRNAs were classified into different subgroups. The expression levels of 4 lncRNAs: HIF1A-AS1, PVT1, CBR3-AS1 and UCA1 both in tumor and plasma were further confirmed in 20 gastric patients by real-time PCR assay. Then, the correlations between the tissue and plasma of these 4 lncRNA levels were assessed. Our data show that there was a significantly positive correlation of UCA1 expression levels between tumor tissues and plasma (r = 0.931). Furthermore, the specificity and sensitivity of PVT-1 and UCA1 were evaluated by receiver operating characteristic (ROC) curve. The results demonstrated that plasma UCA1 provided the higher diagnostic performance for detection of GC (AUC = 0.928; P < 0.001) than PVT-1 (AUC = 0.731; P < 0.01). Taken together, our study suggested that plasma UCA1 levels could be a promising candidate of noninvasive biomarker for GC early diagnosis.

Colorectal cancer (CRC) is one of the major healthcare problems worldwide. A lot of miRNAs are aberrantly expressed in CRC and involved in its development and progression. The purpose of this study was to investigate the expression and function of miR-503 in CRC.

MicroRNAs are small noncoding RNA molecules that regulate gene expression at the post-transcriptional level. Compelling evidence reveals that there is a causative link between microRNAs deregulation and lung cancer development and metastasis. The aim of present study was to explore the function of miR-140-3p in the development and metastasis of lung cancer cell. Using real-time PCR, we detected the miR-140-3p expression of lung cancer tissues and its pared non-lung cancer tissue. Then, we evaluated the role of miR-140-3p in cell proliferation, invasion and migration using MTT, colony formation assay, Transwell invasion and Transwell migration assay in lung cancer cell lines. As a result, miR-140-3p expression level was lower in lung cancer tissues compared to adjacent normal lung cancer tissue. After miR-140-3p was upregulated in A549 or H1299 cells, cell proliferation, invasion and migration was notably attenuated. Furthermore, we identified ATP6AP2, which is associated with adenosine triphosphatases (ATPases), was a directly target of miR-140-3p in lung cancer cells. In conclusion, our data suggest miR-140-3p/ATP6AP2 axis might act as a potential therapeutic biomarker for lung cancer.