Presence of Porphyromonas gingivalis in esophagus and its association with the clinicopathological characteristics and survival in patients with esophageal cancer

BACKGROUND: Mounting evidence suggests a causal relationship between specific bacterial infections and the development of certain malignancies. However, the possible role of the keystone periodontal pathogen, Porphyromonas gingivalis, in esophageal squamous cell carcinoma (ESCC) remains unknown. Therefore, we examined the presence of P. gingivalis in esophageal mucosa, and the relationship between P. gingivalis infection and the diagnosis and prognosis of ESCC. METHODS: The presence of P. gingivalis in the esophageal tissues from ESCC patients and normal controls was examined by immunohistochemistry using antibodies targeting whole bacteria and its unique secreted protease, the gingipain Kgp. qRT-PCR was used as a confirmatory approach to detect P. gingivalis 16S rDNA. Clinicopathologic characteristics were collected to analyze the relationship between P. gingivalis infection and development of ESCC. RESULTS: P. gingivalis was detected immunohistochemically in 61 % of cancerous tissues, 12 % of adjacent tissues and was undetected in normal esophageal mucosa. A similar distribution of lysine-specific gingipain, a catalytic endoprotease uniquely secreted by P. gingivalis, and P. gingivalis 16S rDNA was also observed. Moreover, statistic correlations showed P. gingivalis infection was positively associated with multiple clinicopathologic characteristics, including differentiation status, metastasis, and overall survival rate. CONCLUSION: These findings demonstrate for the first time that P. gingivalis infects the epithelium of the esophagus of ESCC patients, establish an association between infection with P. gingivalis and the progression of ESCC, and suggest P. gingivalis infection could be a biomarker for this disease. More importantly, these data, if confirmed, indicate that eradication of a common oral pathogen could potentially contribute to a reduction in the overall ESCC burden. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13027-016-0049-x) contains supplementary material, which is available to authorized users

Microarray Expression Profile Analysis of Long Non-Coding RNAs in Human Gastric Cardiac Adenocarcinoma

Background/Aims: Long noncoding RNAs (lncRNAs) are pervasively transcribed and have been shown to regulate key biological processes that maintain normal cellular functions. Abnormal regulation of these lncRNAs can promote tumorigenesis through resulting aberrant cellular essential functions. however, the roles of lncRNAs played in the development of gastric cardiac adenocarcinoma (GCA) remain unknown. With this work we aimed to show the expression profile of lncRNAs in GCA tissues compared with paired adjacent noncancerous tissue using microarray analysis in order to interrogate potential carcinogenesis molecular mechanisms of GCA from lncRNA level. Methods: In this study, total RNA was isolated from 15 pairs of GCA tissue, cancerous and non-cancerous, and hybridized to arraystar lncRNA V2.0 chips containing probes representing 33,000 lncRNA genes. Quantitative real-time polymerase chain reaction (PCR) was used to validate 6 up-regulated and 6 down-regulated lncRNAs. Bioinformatic analysis including gene ontology(GO) analysis, pathway analysis and network analysis was done for further investigation. Results: Pathway analysis indicated that 8 pathways corresponded to downregulated transcripts and that 20 pathways corresponded to up-regulated transcripts (p-value cut-off is 0.05). GO analysis showed that the highest enriched GOs targeted by up-regulated transcripts were tissue homeostasis and the highest esenriched GOs targeted by the downregulated transcripts were tissue homeostasis. Conclusion: Our study is the first to interrogate differentially expressed lncRNAs in human GCA tissues and indicates that lncRNAs may be used as novel candidate biomarkers for the clinical diagnosis of GCA and potential targets for further therapy

GASC1 Promotes Stemness of Esophageal Squamous Cell Carcinoma via NOTCH1 Promoter Demethylation

The highest incidence of esophageal squamous cell carcinoma (ESCC) occurs in China. Cancer stem cells play key roles for tumor progression. Gene amplified in squamous cell carcinoma 1 (GASC1) is essential to maintain self-renewal and differentiation potential of embryonic stem cells. This study aimed to reveal the effect and mechanism of GASC1 on ESCC stemness. The biological function of GASC1 in ESCC was evaluated both in vitro and in vivo. ChIP assay was performed to determine the molecular mechanism of GASC1 in epigenetic regulation of NOTCH1. We found that GASC1 expression was increased in poor differentiated ESCC cells and tissues. ESCC patients with a high level of GASC1 presented a significantly worse survival rate. GASC1 expression in purified ALDH+ ESCC cells was significantly higher than that in ALDH- cells. The stemness of ESCC was dramatically decreased after GASC1 blockade. Furthermore, blockade of GASC1 decreased NOTCH1 expression via increase of NOTCH1 promoter H3K9me2 and H3K9me3. Moreover, the impaired stemness after blockade of GASC1 could be reversed after transfection of NOTCH1 overexpression lentiviral vector. GASC1 promoted stemness in ESCC cells via NOTCH1 promoter demethylation. Therefore, GASC1/NOTCH1 signaling might be a potential therapeutic target for the treatment of ESCC patients

KDM4C, a H3K9me3 Histone Demethylase, is Involved in the Maintenance of Human ESCC-Initiating Cells by Epigenetically Enhancing SOX2 Expression

Our studies investigating the existence of tumor-initiating cell (TIC) populations in human esophageal squamous cell carcinoma (ESCC) had identified a subpopulation of cells isolated from ESCC patient-derived tumor specimens marked by an ALDHbri+ phenotype bear stem cell-like features. Importantly, KDM4C, a histone demethylase was enhanced in ALDHbri+ subpopulation, suggesting that strategies interfering with KDM4C may be able to target these putative TICs. In the present study, by genetic and chemical means, we demonstrated that, KDM4C blockade selectively decreased the ESCC ALDHbri+ TICs population in vitro and specifically targeted the TICs in ALDHbri+-derived xenograft, retarding engraftment. Subsequent studies of the KDM4C functional network identified a subset of pluripotency-associated genes (PAGs) and aldehyde dehydrogenase family members to be preferentially down-regulated in KDM4C inhibited ALDHbri+ TICs. We further supported a model in which KDM4C maintains permissive histone modifications with a low level of H3K9 methylation at the promoters of several PAGs. Moreover, ectopic expression of SOX2 restored KDM4C inhibition-dependent ALDHbri+ TIC properties. We further confirmed these findings by showing that the cytoplasmic and nuclear KDM4C staining increased with adverse pathologic phenotypes and poor patient survival. Such staining pattern of intracellular KDM4C appeared to overlap with the expression of SOX2 and ALDH1. Collectively, our findings provided the insights into the development of novel therapeutic strategies based on the inhibition of KDM4C pathway for the eliminating of ESCC TIC compartment

Chemoradiation versus oesophagectomy for locally advanced oesophageal cancer in Chinese patients: study protocol for a randomised controlled trial

Abstract Background Surgery is the gold standard treatment for local advanced disease, while definitive concurrent chemoradiotherapy (DCRT) is recommended for those who are medically unable to tolerate major surgery or medically fit patients who decline surgery. The primary aim of this trial is to compare the outcomes in Chinese patients with oesophageal squamous cell cancer with locally advanced resectable disease who have received either surgery or DCRT. Methods/design One hundred ninety-six patients with T1bN + M0 or T2-4aN0-2 M0 oesophageal squamous cell cancer will be randomised to the DCRT group or the surgery group. In the DCRT group, patients will be given intensity-modulated radiation therapy (IMRT) with 50 Gy/25 fractions and basic chemotherapy with 5-fluorouracil regimens. In the surgery group, patients will receive neoadjuvant chemoradiotherapy (NCRT) and standard oesophagectomy. Five years of follow-up will be scheduled for patients. The primary endpoints are 2-year/5-year overall survival; the secondary endpoints are 2-year/5-year progression-free survival, treatment-related adverse events and the patients’ quality of life. The main evaluation methods include oesophagoscopy, endoscopic ultrasonography and biopsy, oesophageal barium meal, computed tomography, positron emission tomography-computed tomography, blood tests and questionnaires. Discussion The preponderant oesophageal cancer pathology type is dramatically different in western Caucasian and Asian oesophageal cancer patients: Caucasian patients present with 80% adenocarcinomas, and Asians patients present with 95% squamous cell carcinomas. This phenomenon needs more in-depth studies to elucidate the differences in these populations. Based on the results of this study, we will show whether DCRT will benefit patients more than oesophagectomy. This study will contribute more evidence to the management of oesophageal squamous cell cancer. Trial registration ClinicalTrials.gov, NCT02972372. Registered on 26 November 2016