Extracellular volume fraction determined by equilibrium contrast-enhanced CT for the prediction of the pathological complete response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

OBJECTIVES: To determine the extracellular volume (ECV) fraction derived from equilibrium contrast-enhanced CT for predicting pathological complete response (pCR) after neoadjuvant chemoradiotherapy (NCRT) in locally advanced rectal cancer (LARC). METHODS: The ECV fraction before NCRT (ECVpre) and/or ECV after NCRT (ECVpost) of rectal tumors was assessed, and ECVΔ was calculated as ECVpost - ECVpre. The histopathologic tumor regression grading (TRG) was assessed. pCR (TRG 0 grade) was defined as the absence of viable tumor cells in the primary tumor and lymph nodes. Demographic and clinicopathological characteristics and ECV fraction were compared between the pCR and non-pCR groups. A mixed model was constructed by logistic regression. The performance for predicting pCR was assessed with the area under the receiver-operator curve (AUC). The AUCs of the different methods were compared by the method proposed by DeLong et al. RESULTS: Seventy-five patients were included; 17 achieved pCR, and 58 achieved non-pCR. The ECVpost (17.05 ± 2.36% vs. 29.94 ± 1.20%; p < 0.001) and ECVΔ (- 17.01 ± 3.01% vs. 0.44 ± 1.45%; p < 0.001) values in the pCR group were significantly lower than those in the non-pCR group. The mixed model that combined ECVpost with ECVΔ achieved an AUC of 0.92 (95% confidence interval (CI) = 0.81-0.98), which was higher than that of ECVpost (AUC, 0.91 (95% CI = 0.80-0.97); p = 0.60) or ECVΔ (AUC, 0.90 (95% CI = 0.79-0.97); p = 0.61). CONCLUSIONS: ECVpost and ECVΔ determined by using equilibrium contrast-enhanced CT were useful in distinguishing between pCR and non-pCR patients with LARC who received NCRT. KEY POINTS: • ECVpost and ECVΔ (ECVpost - ECVpre) differed significantly between the non-pCR and pCR groups. • ECVpre cannot be used to predict the efficacy of neoadjuvant chemoradiotherapy. • ECVpost combined with ECVΔ had the best performance with an AUC of 0.92 for predicting pCR after NCRT in LARC.

Efficacy and safety of apatinib in recurrent/metastatic nasopharyngeal carcinoma: A pilot study.

BACKGROUND: There is no standard-of-care for recurrent, metastatic nasopharyngeal carcinoma (rmNPC) after first-line chemotherapy. Here, we report the efficacy and safety data of apatinib in rmNPC patients. METHODS: Thirty-five biopsy-proven rmNPC patients received apatinib at 500 mg/day under a compassionate access programme. Primary end-point was objective response rate (ORR; RECIST v1.1). Kaplan-meier method was used to estimate progression-free survival (PFS) and overall survival (OS). Toxicity was assessed by CTCAE v4.0. RESULTS: 82.9% (29 of 35) of patients had poly-metastatic rmNPC. All patients, except five, were platinum-refractory; 37.1% (13 of 35) received ≥ 2 lines. Median number of apatinib cycles was 4.0 (IQR: 2.0-8.0). ORR was 31.4% (11 of 35 [95% CI: 16.9-49.3]) and disease control rate was 74.3% (26 of 35 [95% CI: 56.7-87.5]); 11 (31.4%) and 4 (11.4%) patients demonstrated response for ≥ 6 and ≥ 12 months, respectively. Median PFS and OS was 3.9 (95% CI: 3.1-5.5) months and 5.8 (95% CI: 4.5-8.0) months, respectively. Among the ≥ 12-month responders, all patients had pre-apatinib EBV DNA titer of <700 (range: 353-622) copies/ml; this was consistent with the association of PFS with pre-apatinib EBV DNA titer (adjusted HR 3.364 [95% CI: 1.428-7.923] for ≥ 4000 copies/ml, P = 0.006). 42.9% (15 of 35) of patients required dose reduction. Nonetheless, only five (14.3%) patients suffered from G3 toxicities (two haematological, one hypertension, one hand-foot syndrome and one elevated aminotransferases). CONCLUSION: Our data suggests potential efficacy of apatinib in rmNPC patients. Although incidence of severe toxicities was low, dose modification was required in 42.9% of patients.

[Preparation and characterization of human phage display antibody against peroxiredoxin I of lung adenocarcinoma].

OBJECTIVE: To construct a human phage antibody library and screen the single chain variable fragment (ScFv) antibudies to peroxiredoxin I (Prx I) of lung adenocarcinoma. METHODS: The total RNA was isolated from the lymph nodes of lung cancer patients to amplify V(H) and V(L) genes by RT-PCR. V(H) and V(L) were linked with a DNA linker by SOE-PCR to construct the single chain variable fragment gene. The ScFvs were coloned into the phage vector pCANTAB5E. The insert ratio of the ScFv antibody library was identified by PCR, and the products were digested by SfiI/NotI and analyzed with 1% agarose gel electrophoresis. Three rounds of panning against lung adenocarcinoma cell line A549 and Prx I were performed, and the positive clones were identified for soluble expression. The soluble antibodies were identified by SDS-PAGE and Western blotting, and ELISA and immunocytochemistry were used to characterize the activity of the antibodies. RESULTS: A recombination phage antibody library was constructed. The insert ratio of ScFv gene was 77% (23/30), and enzyme digestion identified the target product. The sixth phage harvest resulted in a yield 180 folds of that of the first one. Positive reactions to A549 cells were detected in 6 of 10 random clones, with a positivity rate of 60%. The soluble human ScFvs against Prx I of lung adenocarcinoma were expressed in E. coli HB2151 and confirmed by SDS-PAGE and Western blotting. ELISA and immunocytochemistry demonstrated a relative specific affinity of the soluble antibodies to A549 cells. CONCLUSION: ScFv antibodies against lung adenocarcinoma have been acquired by phage display antibody library technique, and the soluble antibodies have a relative avidity specific to human lung adenocarcinoma A549 cells overexpressing PrxI.

[Inhibitory effect of novel internalized fully human phage antibody fragments on proliferation of lung adenocarcinoma cell line overexpressing peroxiredoxin I].

BACKGROUND AND OBJECTIVE: Previous researches have implicated the close relationship between peroxiredoxin I (Prx I) and cancer progression. A lung adenocarcinoma-related human phage antibody library has been constructed by using phage display techniques. This study was to screen out the single chain variable fragment (scFv) antibodies from the library against a lung adenocarcinoma cell line overexpressing Prx I and to analyze their anti-proliferation ability. METHODS: The insertion ratio of scFv gene was identified by polymerase chain reaction (PCR). The products were digested by Sfi I and Not I, and analyzed on 1% agarose gel. Three rounds of panning against lung adenocarcinoma cell line A549 and Prx I were performed separately, and the positive clones were chosen for soluble expression. The internalization of radiolabeled scFv fragments was then quantified. The proliferation and apoptosis of A549 cells were detected by MTT assay and flow cytometry (FCM). The protein expression of Prx I in A549 cells was analyzed by Western blot. RESULTS: The insertion ratio of scFv gene was 77% (23/30) and enzyme digestion showed the target products. The sixth phage harvest yielded 180 times as much as that of the first one. Positive reactions with A549 cells were detected in six (60%) of ten random clones. The human scFv fragments against Prx I of lung adenocarcinoma were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent assay (ELISA). The internalized scFvs mediated cell apoptosis and Prx I expression down-regulation. CONCLUSIONS: The scFv fragments against Prx I of lung adenocarcinoma are acquired by screening the phage antibody library. The soluble antibodies have specific avidity and inhibitory effect on proliferation of human lung adenocarcinoma cells.

Production and radioimmunoimaging of novel fully human phage display recombinant antibodies and growth inhibition of lung adenocarcinoma cell line overexpressing Prx I.

The Peroxiredoxin I (Prx I) is a member of the Peroxiredoxin family, which is overexpressed in many diverse tumor types and is an anti-apoptosis protein for tumor cell proliferation and survival. Therapeutic strategies targeting the Prx I may therefore be effective broad-spectrum anticancer agents. We constructed a phage display single-chain variable fragment (scFv) antibody library and sieve out the fully human, lung adenocarcinoma-sepcific monoclonal antibodies. The selection on Prx I was performed using above-mentioned lung adenocarcinoma-sepcific monoclonal antibodies with high affinity to Prx I overexpressing lung adenocarcinoma cells. The candidate scFv sequences, based on enzyme-linked immunosorbent assay (ELISA) screening data, were chosen for soluble expression, and a 30 kDa band was observed on polyacrylamide gel electrophoresis as predicted. The purified antibodies were characterized by immunoblotting and showed high specificity to Prx I-overexpressing lung adenocarcinoma cells A549. Radioimmunoimaging was taken to evaluate specificity and distribution of antibodies in vivo. The radiolocalization index (RI) of tumor/serum and tumor/muscle gradually increased, reaching its peak (4.06 +/- 0.13 and 5.17 +/- 0.97, respectively) at 48 h postadministration. Single photon emission computed tomography (SPECT) imaging showed the radioactivity was aggregated in tumor locations and tumor imaging was clearly observed. The internalized scFv resulted in antibody-mediated cell apoptosis and downregulation of Prx I expression. These results demonstrate that the scFv possesses strong antitumor activity on lung adenocarcinoma and may therefore be an effective therapeutic candidate for the treatment of cancers that are dependent on Prx I for growth and survival.