Enediyne-activated, EGFR-targeted human ß-defensin 1 has therapeutic efficacy against non-small cell lung carcinoma.

Human ß-defensins contain an oncolytic motif that binds to tumor cell membranes and mediate permeabilization, rapid induction of cytolysis, and apoptosis. Previous studies have indicated that a fragment of the mature human ß-defensin-1 (HBD1) peptide (DF) has antitumor properties. While targeted drug treatments using fusion proteins have been shown to increase drug efficacy, this phenomenon has not been studied for this defensin. Thus, in this study, we designed and prepared a fusion protein containing this HBD1 fragment and an epidermal growth factor receptor (EGFR)-targeting oligopeptide (Ec) as well as lidamycin (LDM), an extremely potent cytotoxic antitumor antibiotic, which consists of an apoprotein (LDP) and a highly active enediyne (AE). The fusion protein (Ec-LDP-DF) and its enediyne-integrated fusion protein (Ec-LDP(AE)-DF) were then purified and used to treat lung carcinoma cells in culture as well as lung carcinoma xenograft mouse models. The multifunctional fusion protein Ec-LDP-DF was shown to effectively bind to EGFR-expressing tumor cells. Furthermore, the enediyne-energized Ec-LDP(AE)-DF analog exhibited extremely potent cytotoxicity in NSCLC cell lines and an IC50 less than 10-10 mol/L. Ec-LDP(AE)-DF also significantly inhibited the growth of human carcinoma A549 and H460 xenografts in athymic mice at well-tolerated doses. Treatment resulted in cell cycle arrest and apoptosis in a dose-dependent manner. EGF-stimulated EGFR phosphorylation was also abolished by Ec-LDP(AE)-DF. In summary, our understanding of the role of defensins in cancer development and progression is continually expanding, and Ec-LDP(AE)-DF is a promising cancer cell-targeting agent for NSCLC.

[Correlation of VEGF and Ki67 expression with sensitivity to neoadjuvant chemoradiation in rectal adenocarcinoma].

OBJECTIVE: To investigate the correlation of expression of vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (Ki67) with sensitivity to neoadjuvant chemoradiation in rectal adenocarcinoma. METHODS: Samples of pretreatment biopsies and the resected specimens after neoadjuvant therapy in 32 patients with rectal adenocarcinoma were collected, and the expression of Ki67 and VEGF were detected by immunohistochemistry using specific antibodies. The correlation of Ki67 and VEGF expression with clinicopathological factors were analyzed. RESULTS: The level of VEGF expression was significantly correlated with lymph node metastasis (P = 0.033), depth of tumor invasion (P = 0.007) and TNM stage (P = 0.016), but not with histological type, tumor size, age and gender of the patients (P > 0.05). However, VEGF expression was found to be negatively and significantly correlated with the sensitivity to neoadjuvant chemoradiation (P = 0.016), and a transient increase of VEGF expression was detected in the resected specimens after neoadjuvant therapy (P = 0.035). Ki67 labeling index (Ki67-LI) was found to be significantly correlated with lymph node metastasis (P = 0.028), but not with tumor size, age and gender of the patients (P > 0.05). It was also found that tumors with lower Ki67-LI expression were more sensitive to neoadjuvant therapy than that with higher expression of Ki67-LI (P = 0.032). In contrast with VEGF, the Ki67 expression level decreased after neoadjuvant therapy, but no statistical significance was found between pretreatment and posttreatment specimens (P > 0.05). CONCLUSION: The preliminary results of this study demonstrate that the expression of VEGF and Ki67 in pretreatment biopsy of rectal adenocarcinoma may be used as a biomarker to predict tumor response to neoadjuvant chemoradiation.

PDCD4 as a predictor of sensitivity to neoadjuvant chemoradiotherapy in locally advanced rectal cancer patients.

OBJECTIVE: The purpose of this study was to examine the role of programmed cell death 4 (PDCD4) expression in predicting tumor response to neoadjuvant chemoradiotherapy and outcomes for patients with locally advanced rectal cancer. METHODS: Clinicopathological factors and expression of PDCD4 were evaluated in 92 patients with LARC treated with nCRT. After the completion of therapy, 4 cases achieved clinical complete response (cCR), and thus the remaining 88 patients underwent a standardized total mesorectal excision procedure. There were 38 patients (41.3%) with a good response (TRG 3-4) and 54 (58.7%) with a poor one (TRG 0-2). RESULTS: Immunohistochemical staining analyses showed that patients with high expression of PDCD4 were more sensitive to nCRT than those with low PDCD4 expression (P=0.02). High PDCD4 expression before nCRT and good response (TRG3-4) were significantly associated with improved 5-year disease-free survival and 5-year overall survival (P<0.05). Multivariate analysis demonstrated that the pretreatment PDCD4 expression was an independent prognostic factor. CONCLUSION: Our study demonstrated that high expression of PDCD4 protein is a useful predictive factor for good tumor response to nCRT and good outcomes in patients with LARC.

Circulating lymphocytes as predictors of sensitivity to preoperative chemoradiotherapy in rectal cancer cases.

OBJECTIVE: The objective of this study was to identify clinical predictive factors for tumor response after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). METHODS: All factors were evaluated in 88 patients with LARC treated with nCRT. After a long period of 4-8 weeks of chemoradiotherapy, 3 patients achieved clinical complete response (cCR) and thus aggressive surgery was avoided, and the remaining 85 patients underwent a curative-intent operation. The response to nCRT was evaluated by tumor regression grade (TRG) system. RESULTS: There were 32 patients (36.4%) with good tumor regression (TRG 3-4) and 56 (63.6%) with poor tumor regression (TRG 0-2). Lymphocyte counts and ratios were higher in good response cases (P=0.01, 0.03, respectively) while neutrophil ratios and N/L ratios were higher in poor response cases (P=0.04, 0.02, respectively). High lymphocyte ratios before nCRT and good tumor regression (TRG3-4) were significantly associated with improved 5-year disease-free survival (P<0.05). Pretreatment nodal status was also significantly associated with 5-year disease-free survival and 5-year overall survival (P<0.05). Multivariate analysis confirmed that the pretreatment lymphocyte ratio and lymph nodal status were independent prognostic factors. CONCLUSION: Our study suggested that LARC patients with high lymphocyte ratios before nCRT would have good tumor response and high 5-year DFS and OS.

Cytokeratin 19 fragment antigen 21-1 as an independent predictor for definitive chemoradiotherapy sensitivity in esophageal squamous cell carcinoma.

BACKGROUND: Patients with esophageal squamous cell carcinoma (ESCC) undergoing definitive chemoradiotherapy (CRT) seem to have a disparity in therapeutic response. The identification of CRT sensitivity-related clinicopathological factors would be helpful for selecting patients most likely to benefit from CRT. Cytokeratin 19 fragment antigen 21-1 (CYFRA21-1) and carcinoembryonic antigen (CEA) have been reported as useful tumor markers for esophageal cancer. The aim of this study was to examine the predictive value of CYFRA21-1 in comparison with CEA and other clinicopathological factors in patients with ESCC treated with definitive CRT. METHODS: Pretreatment serum CYFRA21-1 and CEA levels were measured by immunoradiometric assays. The relationships between pretreatment clinicopathological factors and the efficacy of CRT were analyzed. Overall survival (OS) was estimated by univariate and multivariate analysis. RESULTS: The results from a univariate analysis indicated that the efficacy of CRT was significantly associated with the serum levels of CYFRA21-1 and CEA before treatment (P = 0.001 and P = 0.023, respectively). It also indicated that the efficacy of CRT was significantly associated with the pretreatment tumor location (P = 0.041). By Logistic regression analysis, the independent predictive factor associated with efficacy of CRT was CYFRA21-1 (P = 0.002). The OS of the patients with high CYFRA 21-1 levels was worse than that of those with low CYFRA21-1 levels (P = 0.001). In multivariate analysis, a low level of CYFRA21-1 was the most significant independent predictor of good OS (P = 0.007). CONCLUSIONS: CEA and tumor location may be useful in predicting the sensitivity of ESCC to CRT. CYFRA21-1 may be an independent predictor for definitive CRT sensitivity in ESCC.

Prognostic significance of CYFRA21-1, CEA and hemoglobin in patients with esophageal squamous cancer undergoing concurrent chemoradiotherapy.

PURPOSE: To evaluate the prognostic value of serum CYFRA21-1, CEA and hemoglobin levels regarding long-term survival of patients with esophageal squamous cell carcinoma (ESCC) treated with concurrent chemoradiotherapy (CRT). METHODS: Age, gender, Karnofsky Performance Status (KPS), tumor location, tumor length, T stage, N stage and serum hemoglobin, and CYFRA21-1 and CEA levels before concurrent CRT were retrospectively investigated and related to outcome in 113 patients receiving 5-fluorouracil and cisplatin combined with radiotherapy for ESCC. The Kaplan-Meier method was used to analyze prognosis, the log-rank to compare groups, the Cox proportional hazards model for multivariate analysis, and ROC curve analysis for assessment of predictive performance of biologic markers. RESULTS: The median survival time was 20.1 months and the 1-, 2-, 3-, 5- year overall survival rates were 66.4%, 43.4%, 31.9% and 15.0%, respectively. Univariate analysis showed that factors associated with prognosis were KPS, tumor length, T-stage, N-stage, hemoglobin, CYFRA21-1 and CEA level. Multivariate analysis showed T-stage, N-stage, hemoglobin, CYFRA21-1 and CEA level were independent predictors of prognosis. By ROC curve, CYFRA21-1 and hemoglobin showed better predictive performance for OS than CEA (AUC= 0.791, 0.704, 0.545; P=0.000, 0.000, 0.409). CONCLUSIONS: Of all clinicopathological and molecular factors, T stage, N stage, hemoglobin, CYFRA21-1 and CEA level were independent predictors of prognosis for patients with ESCC treated with concurrent CRT. Among biomarkers, CYFRA21-1 and hemoglobin may have a better predictive potential than CEA for long-term outcomes.