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Background Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer. Approximately 80% of patients initially diagnosed with locally advanced or metastatic disease survive only 4–11 months after diagnosis. Tremendous efforts have been made toward understanding the biology of PDAC. Results In this study, we first utilized next-generation sequencing technique and existing microarray datasets to identify significant differentially expressed genes between PDAC and non-tumor adjacent tissue. By comparing top significant survival genes in PDAC Gene Expression Profiling Interactive Analysis database and PDAC transcriptome data from patients, our integrated analysis discovered five potential central genes (i.e., MYEOV, KCNN4, FAM83A, S100A16, and DDX60L). Subsequently, we analyzed the cellular functions of the potential novel oncogenes MYEOV and DDX60L, which are highly expressed in PDAC cells. Notably, the knockdown of MYEOV and DDX60L significantly inhibited the metastasis of cancer cells and induced apoptosis. Further RNA sequencing analyses showed that massive signaling pathways, particularly the TNF signaling pathway and nuclear factor-kappa B (NF-κB) signaling pathway, were affected in siRNA-treated cancer cells. The siDDX60L and siMYEOV significantly inhibited the expression of chemokine CXCL2, which may potentially affect the tumor microenvironment in PDAC tissues. Conclusions The present findings identified the novel oncogene DDX60L, which was highly expressed in PDAC. Transcriptome profiling through siRNA knockdown of DDX60L uncovered its functional roles in the PDAC in humans.

Background: Chemotherapy-related adverse events may restrain taxane/cisplatin administration as a regimen for patients with esophageal squamous cell carcinoma. Genetic polymorphisms may contribute to adverse event susceptibility. Method & results: The authors genotyped ten SNPs from five genes (rs1045642, rs2032582 and rs3213619 of ABCB1; rs2231137 and rs2231142 of ABCG2; rs246221 of ABCC1; rs3740066 of ABCC2; and rs10771973, rs12296975 and rs1239829 of FGD4) in 219 patients with esophageal squamous cell carcinoma treated with taxane/cisplatin. Patients with severe toxicities were compared with those with minor or no adverse events by unconditional logistic regression models and semi-Bayesian shrinkage. After adjustment for age and sex, with the null prior, FGD4 rs1239829 was statistically significantly related to grade 3–4 leukopenia (odds ratio [95% CI] in dominant model = 1.77 [1.04–3.03]). Conclusion: The minor allele of FGD4 rs1239829 was related to grade 3–4 leukopenia in patients with esophageal squamous cell carcinoma treated with taxane/cisplatin, with unclear biological mechanism.

Esophageal squamous cell carcinoma (ESCC) is a tumor composed of heterogeneous cells that easily become radioresistant, which leads to tumor recurrence. The most commonly used treatment for ESCC is fractionated irradiation (FIR) therapy that utilizes ionizing radiation to directly induce cytotoxic cell death. However, this treatment may not be able to eliminate all cancer cells due to high adaptive evolution. To determine whether the transcriptome dynamics during ESCC recurrence formation are associated with FIR response, an in vitro cell culture model for ESCC radioresistance that mimics the common radiotherapy process in patients with ESCC was established in the present study. High-throughput sequencing analysis of in vitro cultured ESCC cells was performed using different cumulative irradiation doses, as well as tumor samples from FIR-treated patients with ESCC before and after the development of radioresistance. Radioresistance-associated genes and signaling pathways that were aberrantly expressed in radioresistant ESCC cells were identified, including autophagy-related 9B (regulation of autophagy), DNA damage-inducible transcript 4, myoglobin and plasminogen activator tissue type, which are associated with response to hypoxia, Bcl2-binding component 3, tumor protein P63 and interferon γ-inducible protein 16, which are associated with DNA damage response. The heterogeneity and dynamic gene expression of ESCC cells during acquired radioresistance were further studied in primary (41 single cells), 12 Gy FIR-treated (87 single cells) and 30 Gy FIR-treated (89 single cells) cancer cells using a single-cell RNA sequencing approach. The results of the present study comprehensively characterized the transcriptome dynamics during acquired radioresistance in an in vitro model of ESCC and patient tumor samples at the population and single cell level. Single-cell RNA sequencing revealed the heterogeneity of irradiated ESCC cells and an increase in the radioresistant ESCC cell subpopulation during acquired radioresistance. Overall, these results are of potential clinical relevance as they identify a number of signaling molecules associated with radioresistance, as well as opportunities for the development of novel therapeutic options for the treatment of ESCC.