Use of CT to evaluate pleural invasion in non-small cell lung cancer: measurement of the ratio of the interface between tumor and neighboring structures to maximum tumor diameter.

PURPOSE: To develop a simple noninvasive technique for evaluating pleural invasion by using routine preoperative computed tomography (CT). MATERIALS AND METHODS: The institutional review board approved this retrospective study, and written informed consent was obtained for performing the initial and follow-up CT studies. Preoperative CT findings (169 patients with possible pleural invasion) and pathologic diagnoses after surgical resection were evaluated. The length of the interface between the primary tumor and neighboring structures (arch distance) and the maximum tumor diameter were measured on CT images, after which arch distance-to-maximum tumor diameter ratios were calculated. Receiver operating characteristic (ROC) curves were used to analyze the ratios. RESULTS: Median arch distance-to-maximum tumor diameter ratios for pleural invasion categories (pl1, pl2, pl3) assessed by using the Union Internationale Contre le Cancer TNM staging system were as follows: pl1, 0.206 (25th-75th percentile, 0-0.486); pl2, 0.638 (25th-75th percentile, 0.385-0.830); and pl3, 1.092 (25th-75th percentile, 1.045-1.214) (P < .001 between groups). On the basis of the ROC curves, the cut-off value for invasion was an arch distance-to-maximum tumor diameter ratio of 0.9. When the ratio was greater than 0.9, the sensitivity and specificity for thoracic invasion and area under the ROC curve were 89.7%, 96.0%, and 0.976, respectively, which represents an improvement over values obtained by using conventional criteria (radiologists A and B: 46.7% and 74.2% and 91.3% and 84.8%, respectively). CONCLUSION: When diagnosing T3 or T4 lung cancer based on arch distance-to-maximum tumor diameter ratios, a higher performance level was achieved than that with use of conventional criteria. Measurement of the ratios is a simple noninvasive technique for evaluating pleural invasion at CT.

Chemical synthesis of a very long oligoribonucleotide with 2-cyanoethoxymethyl (CEM) as the 2'-O-protecting group: structural identification and biological activity of a synthetic 110mer precursor-microRNA candidate.

A long RNA oligomer, a 110mer with the sequence of a precursor-microRNA candidate, has been chemically synthesized in a single synthesizer run by means of standard automated phosphoramidite chemistry. The synthetic method involved the use of 2-cyanoethoxymethyl (CEM), a 2'-hydroxyl protecting group recently developed in our laboratory. We improved the methodology, introducing better coupling and capping conditions. The overall isolated yield of highly pure 110mer was 5.5%. Such a yield on a 1-mumol scale corresponds to 1 mg of product and emphasizes the practicality of the CEM method for synthesizing oligomers of more than 100 nt in sufficient quantity for biological research. We confirmed the identity of the 110mer by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, as well as HPLC, electrophoretic methods, and RNase-digestion experiments. The 110mer also showed sense-selective specific gene-silencing activity. As far as we know, this is the longest chemically synthesized RNA oligomer reported to date. Furthermore, the identity of the 110mer was confirmed by both physicochemical and biological methods.

Metabolic Rather than Pathological Response to Preoperative Chemoradiotherapy Is a Stronger Predictor of Survival in cStage IIB-IV Esophageal Cancer.

AIM: We investigated which is the stronger predictor, pathological response or metabolic response, for survival outcome in patients treated with neoadjuvant chemoradiotherapy (NACRT) plus esophagectomy for thoracic esophageal squamous cell carcinoma (TESCC). PATIENTS AND METHODS: Fifty consecutive patients with cStage IIB-IV TESCC were enrolled. We analyzed the pathological response and metabolic response (fractional decrease in tumor maximum standardized uptake value) to NACRT. Independent prognostic factors predictive of 3-year survival were investigated using univariate and multivariate analyses. RESULTS: Among the 50 patients, 10 (20%) showed a pathological complete response (in both tumor and lymph nodes) and 36 (72%) showed grade 2-3 pathological response. Univariate analysis showed that age, gender, cT stage, pathological response and metabolic response to be significant prognostic factors. A subsequent multivariate analysis confirmed metabolic response and gender to be significant prognostic factors. CONCLUSION: Metabolic response for NACRT was an independent prognostic factor and a more powerful predictor of survival compared to pathological response.

A new RNA synthetic method with a 2'-O-(2-cyanoethoxymethyl) protecting group.

A novel method for the synthesis of RNA oligomers with 2-cyanoethoxymethyl (CEM) as the 2'-hydroxyl protecting group has been developed. The new method allows the synthesis of oligoribonucleotides with an efficiency and final purity comparable to that obtained in DNA synthesis. [structure: see text]

Antitumor activity of small interfering RNA/cationic liposome complex in mouse models of cancer.

PURPOSE: The RNA interference effect is an alternative to antisense DNA as an experimental method of down-regulating a specific target protein. Although the RNA interference effect, which is mediated by small interfering RNA (siRNA) or micro-RNA, has potential application to human therapy, the hydrodynamic method usually used for rapid administration of oligonucleotides is unsuitable for use in humans. In this study, we have investigated the antitumor activity of a synthetic siRNA, B717, which is sequence specific for the human bcl-2 oncogene, complexed with a novel cationic liposome, LIC-101. EXPERIMENTAL DESIGN: In a mouse model of liver metastasis, we administered B717/LIC-101 by bolus intravenous injection, adjusting the rate and volume of administration to what is feasible in human therapy. In a mouse model bearing prostate cancer in which the cells were inoculated under the skin, B717/LIC-101 was administered subcutaneously around the tumor. RESULTS: The B717/LIC-101 complex inhibited the expression of bcl-2 protein and the growth of tumor cell lines in vitro in a sequence-specific manner in the concentration range of 3 to 100 nmol/L. Furthermore, the complex had a strong antitumor activity when administered intravenously in the mouse model of liver metastasis. B717 (siRNA) was shown to be delivered to tumor cells in the mouse liver, but only when complexed with LIC-101. The complex also inhibited tumor cell growth in the mouse model bearing prostate cancer. CONCLUSIONS: By combining siRNA with our cationic liposome, we overcame the difficulty of administering siRNA to animals in ways that can be applied in human therapy. Although our siRNA/liposome complex is not yet in clinical trials, it is expected to provide a novel siRNA therapy for cancer patients.

New CT criteria for nodal staging in non-small cell lung cancer.

OBJECTIVE: The purpose of our study was to develop a simple noninvasive technique for nodal staging using routine preoperative computed tomography (CT). MATERIALS AND METHODS: The institutional review board approved this retrospective study, and written informed consent to perform the initial and follow-up CT studies was obtained from all patients. Preoperative CT findings (n=218 patients with resectable non-small cell lung cancer) and pathological diagnoses after surgical resection were evaluated. Using CT images, lymph node section area, circumference, and lesion attenuation values (LAVs) were drawn freehand, and the short axis (SA) and long axis (LA) were measured using caliper software. Receiver operating characteristic (ROC) curves were then used to analyze the section area, circumference, and LAVs. RESULTS: Based on ROC curves, two cut-off values, lymph node section area >30 mm(2) and circumference >25 mm, showed greater sensitivity for nodal staging than the conventional criterion of lymph node SA ≥10 mm or the LA, SA/LA ratio or LAVs. Using lymph node section area >30 mm(2) for diagnosis, the sensitivity, specificity, and accuracy of nodal staging were 90.5%, 56.3%, and 58.3%, respectively. Using lymph node circumference >25 mm, the values were 76.2%, 70.4%, and 70.8%, respectively. CONCLUSION: Lymph node section area >30 mm(2) and circumference >25 mm can serve as supportive criteria used by radiologists and surgeons to determine nodal staging. If these CT criteria are met, use of a more sensitive procedure such as positron emission tomography or mediastinoscopy is recommended. CONCISE ABSTRACT: CT is used routinely during preoperative management of lung cancer. Based on ROC analyses, the cut-off values for surface area, circumference, the SA/LA ratio, and LAVs for diagnosis of lymph node metastasis were 30 mm(2), 25 mm, 0.65, and 50 Hounsfield units, respectively. Our findings indicate that lymph node surface area >30 mm(2) and circumference >25 mm are supportive criteria that can be used by radiologists and thoracic surgeons to determine nodal staging and surgical indications.

Chemical synthesis of a very long RNA oligomer, a 110mer precursor-miRNA candidate, with 2-cyanoethoxymethyl (CEM) as the 2'-O-protecting group.

A long RNA oligomer, a 110mer with the sequence of a precursor-miRNA candidate, has been chemically synthesized in a single synthesizer run by means of standard automated phosphoramidite chemistry. The synthetic method involved the use of 2-cyanoethoxymethyl (CEM), a 2'-hydroxyl protecting group recently developed in our laboratory. We confirmed the identity of the synthetic 110mer by MALDI-TOF mass spectrometry, as well as HPLC, electrophoretic methods, RNase-digestion experiments, and its in vitro gene-silencing activity. The chemical synthesis of RNA oligomers of more than 100 nucleotides, which has until now been extremely difficult, can be practically realized by the CEM method.

A novel RNA synthetic method with a 2'-O-(2-cyanoethoxymethyl) protecting group.

A novel method for the synthesis of RNA oligomers with 2-cyanoethoxymethyl (CEM) as the 2'-hydroxyl protecting group has been developed. The new method allows the synthesis of oligonucleotides with an efficiency and final purity comparable to that obtained in DNA synthesis.(1) In addition, the CEM method has the potential for application to the synthesis of very long RNA oligonucleotides.

Homo-N-oligonucleotides (N1/N9-C1' methylene bridge oligonucleotides): nucleic acids with left-handed helicity.

Oligonucleotides containing a methylene bridge between N1 or N9 of the heterocyclic base and C1' of the pentofuranosyl ring (homo-N-oligonucleotides) were synthesized. Melting curves revealed that such homo-type oligomers could cross-pair with complementary homo-type or natural oligomers. Circular-dichroic studies provide evidence that the homo-type dimers have a left-handed stacked conformation and further suggest that single-stranded and double-stranded homo-type oligomers adopt a left-handed conformation, while duplexes with natural oligomers or nucleic acids form RNA-like right-handed helices. NMR spectroscopy (NOESY) provides supporting evidence for a left-handed stacked conformation of the homo-type dimer, while atomic force microscopy indicates a left-handed helical conformation of homo-type dsDNA. Homo-type dimers and oligomers showed high resistance to digestion by snake-venom and calf-spleen phosphodiesterases and nuclease S1.

Novel nucleic acids with left-handed helicity.

Oligonucleotides containing a methylene bridge between Nl or N9 of the heterocyclic base and C1' of the pentofuranosyl ring (homo-N-oligonucleotides) were synthesized. Melting curves revealed that such homo-type oligomers could cross-pair with complementary homo-type or natural oligomers. Circular dichroism spectra provide evidence that the homo-type dimers have a left-handed stacked conformation and further suggest that single-stranded and double-stranded homo-type oligomers adopt a left-handed conformation, while duplexes with natural oligomers or nucleic acids form right-handed helices. NMR (NOESY) provides supporting evidence for a left-handed conformation of the homo-type dimer. Atomic force microscopy (AFM) indicates a left-handed helical conformation of homo-type dsDNA.