Effect of SIB-IMRT-based selective dose escalation of local tumor on the prognosis of patients with esophageal cancer.

BACKGROUND: To investigate the effect of SIB-IMRT-based selective dose escalation to local tumor on the prognosis of patients with esophageal cancer (EC). METHODS: A total of 302 EC patients were enrolled. The prognostic factors of the entire group were initially analyzed, and the composition ratios of the two groups and the different doses of each fraction for PTV were compared. The propensity-score matching (PSM) was carried out (1:1 ratio), and the prognostic factors for the two groups were analyzed according to the results of COX. RESULTS: The median overall survival (OS) for all patients was 30.0 months (23.495-36.505 months), and the median disease-free survival (DFS) was 21.3 months (7.698-24.902 months). In multivariate analysis, chemotherapy, cTNM stage and dose-per-fraction for the PTV were independent prognostic factors for OS (P = 0.013, 0.000, 0.028) and DFS (P = 0.033, 0.000, 0.047). Multivariate analysis of patients after PSM revealed that cTNM staging and dose-per-fraction were the independent prognostic factors for OS (P = 0.000, 0.015). Chemotherapy, cTNM staging and dose-per-fraction for the PTV were the independent prognostic factors for DFS (P = 0.025, 0.010, 0.015). There was no significant difference in grade ≥ 2 acute toxicities between the two groups. A subgroup analysis of patients with a single dose of 2 Gy and > 2 Gy in the SIB-IMRT group showed that OS and DFS of the latter were significantly better than those of the former. CONCLUSION: The selective dose escalation to local tumors based on SIB-IMRT technique can improve the survival of patients received radical radiotherapy without increasing toxicities.

Analysis of the causes of failure after radical surgery in patients with PT3N0M0 thoracic esophageal squamous cell carcinoma and consideration of postoperative radiotherapy.

BACKGROUND: Five-year overall survival rate of TESCC after surgery is low (approximately 30% to 60%), so it is meaningful to discuss the significance of PORT. METHODS: We retrospectively collected the data of 227 patients with PT3N0M0 esophageal cancer (EC). The failure pattern after surgery was analyzed. Difference of adjuvant PORT in patients with PT3N0M0 TESCC and the appropriate population were explored based on the relevant studies. RESULTS: There were 58 cases with intrathoracic locoregional recurrence (LRR) after radical surgery and 27 cases with distant metastasis, including 10 cases of recurrence. The recurrence rate of mediastinal lymph nodes in the thoracic cavity was 50.0%. Univariate analysis revealed that compared with patients with middle and lower thoracic EC, the 3/5-year survival rate of patients with upper thoracic EC was significantly lower, accompanied with remarkably higher thoracic LRR. Compared with those with moderately- and well-differentiated TESCC, the 3/5-year survival rate of patients with poorly differentiated TESCC was significantly lower, whereas the distant metastasis rate was notably higher. Multivariate analysis revealed that different lesion locations and different pathologic differentiation were the independent prognostic factors. The lesion location and degree of differentiation were the independent influencing factors for thoracic LRR and distant metastasis, respectively. CONCLUSION: The intrathoracic LRR is the major failure pattern for patients with PT3N0M0 TESCC after conventional two-field lymphadenectomy. In addition, recurrence rate of PT3N0M0 TESCC was significantly higher in upper thoracic EC than in middle and lower thoracic EC. PORT is recommended to patients with PT3N0M0 upper TESCC.

[Study on the Conformation of Soybean Selenoprotein Solution with Spectroscopy Methods].

The structure characteristic of soybean selenoprotein and soy protein isolate (SPI) were investigated with fluorescence, ultraviolet and Fourier transform infrared (FTIR) spectrum. The unfolding process of two proteins was analyzed with fluorescence phase diagram method. The stability of emulsion properties and the influence of concentration, temperature and pH on the conformation of soy selenoproteins were also determined. The results indicated that the covalent disulfide bond of soybean selenoprotein molecules was damaged; the hydrogen bonding become weak; the hydrophobic interactions were enhanced and the protein chain molecules were extended. Soybean selenoprotein displayed only "folding" and "loose" state in solution, which illustrated soybean selenoprotein more tend to hydrolysis when compared with soybean protein. With temperature increasing, the fluorescence quenching effect occurred and the hydrophobicity of soy selenoproteins was also gradually increased, which reflected the protein molecules tends to be folded. In the range of pH 2.8～8.0, the Trp residue of soybean selenoprotein was mainly distributed in the polarity of the external environment and presented different conformational change on both sides of the isoelectric point under different pH value. In acidic environment, the soybean selenoprotein was easy to appear conformational transition from loose to fold. But it was conducive for soybean selenoprotein to existence in loose structure in alkaline conditions. In addition, the emulsifying properties of soybean selenoprotein were analyzed based on UV spectral data. Results showed that lower temperature helps to enhancement the emulsification but unfavorable the stability of the soybean selenoprotein.

Construction of a predictive model of abdominal lymph node metastasis in thoracic esophageal squamous cell carcinoma and preliminary analysis of its effect on target for postoperative radiotherapy.

Purpose: To investigate the influencing factors of abdominal lymph node metastasis in thoracic esophageal squamous cell carcinoma (TESCC), and to construct its predictive model, in order to analyze the targets for postoperative radiotherapy. Methods and materials: From January 2008 to December 2014, the clinicopathological data of 479 patients who underwent radical resection for esophageal cancer in the Fourth Hospital of Hebei Medical University were collected and retrospectively analyzed. The influencing factors of postoperative abdominal lymph node metastasis were analyzed, and a predictive model was constructed based on their independent influencing factors. Receiver operating characteristic (ROC) curve was utilized to analyze the predictive value of this model; in the meantime, the postoperative locoregional recurrence (LRR) of this group was analyzed. Results: The postoperative pathology of all patients showed that the lymph node metastasis rate (LNR) was 39.7%, of which the abdominal lymph node metastasis rate was 22.0%. Logistic regression analysis revealed that the patient's lesion location, pN stage, vascular invasion, LND and mediastinal lymph node metastasis were independent risk factors for the positive rate of abdominal lymph nodes after surgery (P = 0.000, 0.000, 0.033, 0.000, 0.000). The probability of abdominal lymph node metastasis was Y = ex/(1 + ex), and X = -5.502 + 1.569 × lesion location + 4.269 × pN stage + 1.890 × vascular invasion + 1.950 × LND-4.248 × mediastinal lymph node metastasis. The area under the ROC curve (AUC) of this model in predicting abdominal lymph node metastasis was 0.962 (95% CI, 0.946-0.977). This mathematical model had a high predictive value for the occurrence of abdominal lymph node metastasis (P = 0.000), and the sensitivity and specificity of prediction were 94.6% and 88.3% respectively. The overall survival rate was significantly higher (X2 = 29.178, P = 0.000), while abdominal lymph node recurrence rate was lower in patients with negative abdominal lymph nodes than in those with negative lymph nodes (1.4%&7.7%, X2 = 12.254, P = 0.000). Conclusion: The lesion location, pN stage, vascular invasion, LND and mediastinal lymph node metastasis are independent influencing factors of abdominal lymph node metastasis in patients with TESCC. The mathematical model constructed by these indicators can accurately predict abdominal lymph node metastasis, which can help clinicians to choose the targets for postoperative radiotherapy.

Preliminary analysis of the benefits of different irradiation types on patients with postoperative locoregional recurrence of esophageal cell squamous carcinoma.

BACKGROUND: To explore the benefits of different types of irradiation on patients with postoperative locoregional recurrence (LRR) of thoracic esophageal squamous cell carcinoma (ESCC). METHODS: We analyzed the medical records of 344 patients with recurrent esophageal cancer (EC) at the Fourth Hospital of Hebei Medical University. All patients met an inclusion criteria that included having postoperative LRR (without distant metastasis), and having received either chemotherapy, radiotherapy, or chemoradiotherapy after LRR. Patients either received elective nodal irradiation (ENI) or involved field irradiation (IFI), with a stratified analysis performed on both groups. SPSS 19.0 software (IBM Corporation, Armonk, NY USA) was then used for statistical analysis. RESULTS: The median overall survival time of all patients after surgery was 33 months [95% confidence interval (CI): 28.3-37.7 months]; the median overall survival time of patients after recurrence after radiotherapy was 12.8 months (95% CI: 11.3-14.3 months). There were 276 cases (80.2%) of single local recurrence after surgery, and 68 cases (19.8%) of multiple local recurrence (≥2). The results of our multivariate analysis showed that the patient's gender, log odds of positive lymph nodes (LODDS), and the number of courses of chemotherapy were all independent factors affecting the patient's prognosis (P=0.003, P<0.001, and P<0.001). The results of stratified analysis showed that patients with esophageal lesion length <5.0 cm, stage N0, ≤9 surgically dissected lymph nodes, no positive regional lymph node metastasis (LNM), and LODDS ≤0.030 could benefit from ENI treatment (X2=4.208, P=0.032; X2=6.262, P=0.012; X2=10.359, P=0.001; X2=6.327, P=0.012; X2=6.026, P=0.014); and patients with ≥16 surgically dissected lymph nodes could benefit from IFI treatment (X2=4.429, P=0.035). CONCLUSIONS: Chemotherapy, radiotherapy, and chemoradiotherapy are all effective modes of treatment for patients with postoperative LRR of EC. Patients with shorter esophageal lesions determined by preoperative esophagography, earlier postoperative pathological N staging, lower LODDS scores, and fewer surgically dissected lymph nodes might benefit more from ENI treatment than from IFI. However, patients with a larger number of lymph nodes dissected during surgery might benefit more from IFI treatment. To further confirm this study's conclusions, multiple prospective studies should be undertaken in the future.

CytoSVM: an advanced server for identification of cytokine-receptor interactions.

The interactions between cytokines and their complementary receptors are the gateways to properly understand a large variety of cytokine-specific cellular activities such as immunological responses and cell differentiation. To discover novel cytokine-receptor interactions, an advanced support vector machines (SVMs) model, CytoSVM, was constructed in this study. This model was iteratively trained using 449 mammal (except rat) cytokine-receptor interactions and about 1 million virtually generated positive and negative vectors in an enriched way. Final independent evaluation by rat's data received sensitivity of 97.4%, specificity of 99.2% and the Matthews correlation coefficient (MCC) of 0.89. This performance is better than normal SVM-based models. Upon this well-optimized model, a web-based server was created to accept primary protein sequence and present its probabilities to interact with one or several cytokines. Moreover, this model was applied to identify putative cytokine-receptor pairs in the whole genomes of human and mouse. Excluding currently known cytokine-receptor interactions, total 1609 novel cytokine-receptor pairs were discovered from human genome with probability approximately 80% after further transmembrane analysis. These cover 220 novel receptors (excluding their isoforms) for 126 human cytokines. The screening results have been deposited in a database. Both the server and the database can be freely accessed at http://bioinf.xmu.edu.cn/software/cytosvm/cytosvm.php.

TKTL1 promotes cell proliferation and metastasis in esophageal squamous cell carcinoma.

Transketolase-like-1 (TKTL1), which is a rate-limiting enzyme in the non-oxidative part of the pentose-phosphate pathway, has been demonstrated to promote carcinogenesis through enhanced aerobic glycolysis. Dysregulation of TKTL1 expression also leads to poor prognosis in patients with urothelial and colorectal cancer. However, the expression pattern and underlying cellular functions in human esophageal squamous cell carcinoma (ESCC) remain largely unexplored. In this study, we measured TKTL1 expression in ESCC cell lines and paraffin-embedded ESCC tumor tissues. Our results revealed that TKTL1 expression was upregulated in all of the four ESCC cell lines and in 61.25% (98/160) of ESCC specimens detected, while only 27.5% (11/40) in normal epithelium. Silencing of TKTL1 expression decreased cell proliferation through inhibiting the expression of MKI67 and cyclins including Ccna2, Ccnb1, Ccnd1 and Ccne1. Meanwhile, down-regulation of TKTL1 also associated with increased apoptotic ratio and altered protein expression of Bcl-2 family in ESCC cells. Furthermore, knockdown of TKTL1 significantly reduced the invasive potential of ESCC cells through up-regulation of anti-metastasis genes (MTSS1, TIMP2 and CTSK) and down-regulation of pr-metastasis genes (MMP2, MMP9, MMP10 and MMP13). Taken together, our results indicate that TKTL1 is associated with a more aggressive behavior in ESCC cells and suppresses its expression or enzyme activity might represents a potential target for developing novel therapies in human ESCCs.