We performed a genome-wide association study of esophageal squamous cell carcinoma (ESCC) by genotyping 1,077 individuals with ESCC and 1,733 control subjects of Chinese Han descent. We selected 18 promising SNPs for replication in an additional 7,673 cases of ESCC and 11,013 control subjects of Chinese Han descent and 303 cases of ESCC and 537 control subjects of Chinese Uygur-Kazakh descent. We identified two previously unknown susceptibility loci for ESCC: PLCE1 at 10q23 (P(Han combined for ESCC) = 7.46 x 10(-56), odds ratio (OR) = 1.43; P(Uygur-Kazakh for ESCC) = 5.70 x 10(-4), OR = 1.53) and C20orf54 at 20p13 (P(Han combined for ESCC) = 1.21 x 10(-11), OR = 0.86; P(Uygur-Kazakh for ESCC) = 7.88 x 10(-3), OR = 0.66). We also confirmed association in 2,766 cases of gastric cardia adenocarcinoma cases and the same 11,013 control subjects (PLCE1, P(Han for GCA) = 1.74 x 10(-39), OR = 1.55 and C20orf54, P(Han for GCA) = 3.02 x 10(-3), OR = 0.91). PLCE1 and C20orf54 have important biological implications for both ESCC and GCA. PLCE1 might regulate cell growth, differentiation, apoptosis and angiogenesis. C20orf54 is responsible for transporting riboflavin, and deficiency of riboflavin has been documented as a risk factor for ESCC and GCA.

BackgroundPlenty of studies have demonstrated the prognostic value of various inflammation-based indexes in cancer. This study was designed to investigate the prognostic value of the C-reactive protein/albumin (CRP/Alb) ratio in esophageal squamous cell carcinoma.MethodsA retrospective study of 423 cases with newly diagnosed esophageal squamous cell carcinoma was conducted. We analyzed the association of the CRP/Alb ratio with clinicopathologic characteristics. The prognostic value was explored by univariate and multivariate survival analysis. In addition, we compared the discriminatory ability of the CRP/Alb ratio with other inflammation-based prognostic scores by evaluating the area under the receiver operating characteristics curves (AUC), including the modified Glasgow Prognostic Score (mGPS), neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR).ResultsThe optimal cut-off value was identified to be 0.095 for the CRP/Alb ratio. A higher level of the CRP/Alb ratio was associated with larger tumor size (P < 0.001), poorer differentiation (P = 0.019), deeper tumor invasion (P = 0.003), more lymph node metastasis (P = 0.015), more distant metastasis (P < 0.001) and later TNM stage (P < 0.001). The CRP/Alb ratio was identified to be the only inflammation-based prognostic score with independent association with overall survival by multivariate analysis (P = 0.031). The AUC value of the CRP/Alb ratio was higher compared with the NLR and PLR, but not mGPS at 6, 12 and 24 months of follow-up. In addition, the CRP/Alb ratio could identify a group of patients with mGPS score of 0 who had comparable overall survival with those with mGPS score of 1.ConclusionsThe CRP/Alb ratio is a novel but promising inflammation-based prognostic score in esophageal squamous cell carcinoma. It is a valuable coadjutant for the mGPS to further identify patients’ survival differences.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1379-6) contains supplementary material, which is available to authorized users.

BackgroundThe cell division cycle 20 homolog (CDC20) is an essential cofactor of the anaphase-promoting complex (APC/C). CDC20 overexpression has been detected in many types of human cancers; however, its clinical role in colorectal cancer remains unknown.MethodsWestern blotting and immunohistochemistry were used to compare CDC20 expression in adjacent non-cancerous, cancerous and liver metastatic tissues as well as in colon cancer cell lines and normal colon epithelial cell lines. Additionally, the correlation of CDC20 expression with patient clinical parameters and its diagnostic value were statistically analyzed.ResultsCDC20 was overexpressed in colon cancer cell lines/primary cancer tissues compared with normal colon epithelial cell lines/adjacent noncancerous tissue samples. Interestingly, CDC20 expression was further increased in metastatic liver tissues. CDC20 protein expression was significantly correlated with clinical stage (P = 0.008), N classification (P = 0.020), M classification (P = 0.013) and pathologic differentiation (P = 0.008). Patients with higher CDC20 expression had a shorter overall survival than those with lower CDC20 expression. Univariate and multivariate analyses indicated that CDC20 expression was an independent prognostic factor (P < 0.001).ConclusionCDC20 may serve as a potential prognostic biomarker of human colorectal cancer.

Oesophageal squamous cell carcinoma (ESCC) is the sixth most common cause of cancer-associated death in the world and novel therapeutic alternatives are urgently warranted. In this study, we investigated the anti-tumour activity and underlying mechanisms of melatonin, an indoleamine compound secreted by the pineal gland as well as naturally occurring plant products, in ESCC cells and revealed that melatonin inhibited proliferation, migration, invasion and induced mitochondria-dependent apoptosis of ESCC cells in vitro and suppressed tumour growth in the subcutaneous mice model in vivo. Furthermore, after treatment with melatonin, the expressions of pMEK, pErk, pGSK3β and pAkt were significantly suppressed. In contrast, treatment of the conventional chemotherapeutic drug fluorouracil (5-Fu) resulted in activation of Erk and Akt, which could be reversed by co-treatment with melatonin. Importantly, melatonin effectively enhanced cytotoxicity of 5-Fu to ESCC in vitro and in vivo. Together, these results suggested that inhibition of Erk and Akt pathway by melatonin have an important role in sensitization of ESCC cells to 5-Fu. Combined 5-Fu and melatonin treatment may be appreciated as a useful approach for ESCC therapy that warrants further investigation.

Constitutive activation and gemcitabine induction of nuclear factor-κB (NF-κB) contribute to the aggressive behavior and chemotherapeutic resistance of pancreatic ductal adenocarcinoma (PDAC). Thus, targeting the NF-κB pathway has proven an insurmountable challenge for PDAC therapy. In this study, we investigated whether the inhibition of NF-κB signaling pathway by melatonin might lead to tumor suppression and overcome gemcitabine resistance in pancreatic tumors. Our results showed that melatonin inhibited activities of NF-κB by suppressing IκBα phosphorylation and decreased the expression of NF-κB response genes in MiaPaCa-2, AsPc-1, Panc-28 cells and gemcitabine resistance MiaPaCa-2/GR cells. Moreover, melatonin not only inhibited cell proliferation and invasion in a receptor-independent manner, but also enhanced gemcitabine cytotoxicity at pharmacologic concentrations in these PDAC cells. In vivo, the mice treated with both agents experienced a larger reduction in tumor burden than the single drug-treated groups in an orthotopic xenograft mouse model. Taken together, these results indicate that melatonin inhibits proliferation and invasion of PDAC cells and overcomes gemcitabine resistance of pancreatic tumors through NF-κB inhibition. Our findings therefore provide novel preclinical knowledge about melatonin inhibition of NF-κB in PDAC and suggest that melatonin should be investigated clinically, alone or in combination with gemcitabine for PDAC treatment.

Fat mass and obesity-associated protein (FTO), an N6-methyladenosine (m6A) demethylase, participates in tumor progression and metastasis in many malignancies, but its role in colorectal cancer (CRC) is still unclear. Here, we found that FTO protein levels, but not RNA levels, were downregulated in CRC tissues. Reduced FTO protein expression was correlated with a high recurrence rate and poor prognosis in resectable CRC patients. Moreover, we demonstrated that hypoxia restrained FTO protein expression, mainly due to an increase in ubiquitin-mediated protein degradation. The serine/threonine kinase receptor associated protein (STRAP) might served as the E3 ligase and K216 was the major ubiquitination site responsible for hypoxia-induced FTO degradation. FTO inhibited CRC metastasis both in vitro and in vivo. Mechanistically, FTO exerted a tumor suppressive role by inhibiting metastasis-associated protein 1 (MTA1) expression in an m6A-dependent manner. Methylated MTA1 transcripts were recognized by an m6A “reader”, insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), which then stabilized its mRNA. Together, our findings highlight the critical role of FTO in CRC metastasis and reveal a novel epigenetic mechanism by which the hypoxic tumor microenvironment promotes CRC metastasis.

IntroductionRight-sided colon cancer (RSCC) and left-sided colorectal cancer (LSCRC) differ with respect to their biology and genomic patterns. This study aimed to examine whether the primary tumor location is associated with the response to cetuximab in patients with metastatic colorectal cancer (mCRC).MethodsPatients with mCRC treated with cetuximab and standard chemotherapy as first- or second-line treatments were compared with randomly chosen patients who were treated with chemotherapy alone between 2005 and 2013. The main outcome measures were the overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). The differences in the outcome were analyzed by using the chi-squared test, Student’s t test, and Kaplan-Meier method.ResultsThe treatment results of 206 patients with mCRC treated with cetuximab and standard chemotherapy as first- or second-line treatments were compared with those of 210 patients who were treated with chemotherapy alone. As a first-line treatment, cetuximab with chemotherapy was associated with a significantly higher ORR (49.4 % vs. 28.6 %, P = 0.005) as well as longer PFS (9.1 vs. 6.2 months, P = 0.002) and OS (28.9 vs. 20.1 months, P = 0.036) than chemotherapy alone in patients with LSCRC. However, cetuximab neither improved the ORR (36.4 % vs. 26.2 %, P = 0.349) nor prolonged PFS (5.6 vs. 5.7 months, P = 0.904) or OS (25.1 vs. 19.8 months, P = 0.553) in patients with RSCC. As a second-line treatment, cetuximab exhibited a tendency to improve the ORR (23.5 % vs. 10.2 %, P = 0.087) and prolong PFS (4.9 vs. 3.5 months, P = 0.064), and it significantly prolonged OS (17.1 vs. 12.4 months, P = 0.047) compared with chemotherapy alone in the patients with LSCRC. In contrast, as a second-line treatment, cetuximab neither improved the ORR (7.1 % vs. 11.4 %, P = 0.698) nor prolonged PFS (3.3 vs. 4.2 months, P = 0.761) or OS (13.4 vs. 13.0 months, P = 0.652) in patients with RSCC.ConclusionsThe addition of cetuximab to chemotherapy in both first- and second-line treatments of mCRC may only benefit patients with primary LSCRC.

The monoclonal antibody trastuzumab has brought survival benefit to patients with advanced gastric cancer (AGC) that have human epidermal growth factor receptor 2 (HER2) over expression or amplification. This study was designed to compare the clinical outcomes of HER2-negative and HER2-positive AGC patients with or without trastuzumab treatment. There were three groups of patients enrolled for analysis. Group A was 51 HER2-positive AGC patients treated with trastuzumab and chemotherapy; group B was a matched control group of 47 HER2-positive patients who received chemotherapy only; group C was a matched group of 251 HER2-negative patients who received chemotherapy. All the patients were enrolled at Sun Yat-sen University Cancer Center or Zhongshan Hospital, Fudan University between January 2010 and December 2012. The primary endpoint was overall survival (OS). The Kaplan-Meier method and log-rank test were used for survival analysis. The median duration of follow-up was 13.5 months (range 5-18.6 months). The median OS of these three groups of patients was 14.8 months, 11.3 months and 14.4 months respectively (p < 0.001). The survival difference between group A and B was significant, p < 0.001. Similarly, there was significant difference between group B and C, p < 0.001. Moreover the survival between group A and C was comparable, p 5 0.281. The median progression-free survival for these three groups was 7.4, 6.0 and 7.2 months. Multivariate analysis confirmed that trastuzumab treatment was an independent prognostic factor in group A and B patients (p 5 0.017). HER2 positive was an independent adverse prognostic factor in group B and C patients (p 5 0.013).In 2008, approximately one million new gastric cancer patients (7.8% of global cancer totals), and 7,38,000 deaths (9.7% of global cancer totals) occurred, making it the fourth most common malignancy and the second leading cause of cancer related death worldwide.1 The incidence rate of gastric carcinoma varies dramatically from one part of the world to another and it is particularly common in Eastern Asia, especially in China.2 Advanced gastric cancer (AGC) patients accounts for 40% of new Chinese gastric cancer patients and had a worse prognosis than early stage diseases. Though first-line chemotherapy for AGC prolongs overall survival (OS) and improves quality of life compared with best supportive care (BSC); the median survival of AGC patients who received palliative chemotherapy is approximately 7-11