Precise structure control of three-state nanomechanical DNA origami devices.

Precise structure switching between all of the three forms of three-state nanomechanical DNA origami devices has been accomplished. A nanomechanical DNA origami device called DNA origami pliers, which consists of two levers of 170-nm long, 20-nm wide, and 2-nm thick connected at a Holliday-junction fulcrum, takes three conformations: closed parallel, closed antiparallel, and open cross forms. They were previously applied to construct detection systems for biomolecules in single-molecular resolution by observing the structure switching between cross form and one of the other two forms under atomic force microscope (AFM). We redesigned DNA origami pliers in this study to let them freely switch between all of the three states including parallel-antiparallel direct switching without taking cross form. By the addition of appropriate switcher strands to the solution, hybridization and dehybridization of particular binder strands that fix the levers into predetermined state were selectively triggered as programmed in their sequence. Circuit structure switching through all of the three states in both of the two opposite direction was even successful with the new design.

Successful salvage surgery followed by second ALK-TKI after alectinib failure in a patient with ALK-positive NSCLC.

BACKGROUND: Anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors (TKIs) have been approved for the therapy of locally advanced non-small cell lung cancer (NSCLC) caused by ALK rearrangement. However, its treatment after failure of initial ALK-TKI therapy remains controversial. CASE PRESENTATION: A 47-year-old woman with a hemosputum was diagnosed with adenocarcinoma of the left lung (cT2bN3M0, stage IIIB). Gene mutation analysis indicated positive ALK translocation. Alectinib was selected as the first-line treatment. Although the treatment effect was determined as a partial response, the main tumor regrew. Alectinib was discontinued, and salvage surgery was performed without causing morbidity. The pathological diagnosis was pleomorphic carcinoma without lymph node metastasis (yp-T2bN0). After surgery, lorlatinib was administered as the second-line treatment for 8 months until the patient could not tolerate continuation. Computed tomography scan revealed no lung cancer recurrence 14 months after discontinuation. CONCLUSIONS: Our experience with this case suggests that salvage surgery after alectinib treatment followed by lorlatinib therapy may be effective for initially unresectable ALK-positive NSCLC.

Aberrant mediastinal mediobasal segmental pulmonary artery in a patient with lung cancer undergoing right lower lobectomy: a case report.

BACKGROUND: A mediastinal mediobasal segmental pulmonary artery (A7) from the right main pulmonary artery is extremely rare. CASE PRESENTATION: We report the case of a 71-year-old woman with an aberrant mediastinal A7 who underwent right lower lobectomy for lung cancer (cT1bN0M0, stage IA2). Preoperative three-dimensional computed tomography (CT) angiography revealed an aberrant mediastinal A7 in the right main pulmonary artery. Right lower lobectomy and mediastinal lymph node dissection were performed. Intraoperatively, A7 was observed between the superior and inferior pulmonary veins and in the front of the lower bronchus near the anterior hilum. The artery was carefully dissected from the caudal side after inferior pulmonary vein dissection. The lung parenchyma, which was within the fissure due to poor lobulation between the middle and lower lobes, was safely divided. CONCLUSIONS: Thoracic surgeons need to carefully evaluate CT angiography or enhanced multidetector CT findings at preoperative conferences and always keep this anomaly in mind.

Tumor Spread Through Air Spaces Is a Predictor of Occult Lymph Node Metastasis in Clinical Stage IA Lung Adenocarcinoma.

INTRODUCTION: In patients with stage IA lung adenocarcinoma (ADC), sublobar resection and tumor spread through air spaces (STAS) are associated with high rates of locoregional recurrence, half of which occur within the regional lymph nodes (LNs). Our objectives were to investigate the association between occult LN metastasis (ONM) and STAS and to assess their prognostic value in patients with clinical stage IA lung ADC. METHODS: The association between STAS and ONM was analyzed in patients who underwent lobectomy and LN dissection for clinical stage IA lung ADC (n = 809). Multivariable logistic regression analysis was carried out to identify predictors of ONM. Site-specific recurrence by surgical procedure was investigated in patients with pathologic node-negative disease (n = 1055) using a competing risk approach. RESULTS: ONM was identified in 129 patients (16%)-one-third of ONMs were located only in intrapulmonary nodes. STAS was more common in patients with ONM than in those without ONM (67% versus 39%; p < 0.001) and in patients with multiple ONMs than in those with a single ONM (86%-89% versus 60%-67%). STAS was a significant predictor of ONM (p = 0.004) on multivariable analysis, independent of tumor size, maximum standardized uptake value, and lymphovascular invasion. In patients with STAS-positive ADC (high ONM risk), the risk of recurrence in the treated lobe and regional LNs increased as the extent of resection decreased (recurrence risk: lobectomy < segmentectomy < wedge resection). In patients with STAS-negative ADC, the risk of locoregional recurrence did not differ by procedure type. CONCLUSIONS: Presence of STAS predicts ONM in patients with clinical stage IA lung ADC and can help stratify risk of recurrence by extent and type of resection.

Expressions of ATF6, XBP1, and GRP78 in normal tissue, atypical adenomatous hyperplasia, and adenocarcinoma of the lung.

Little is known about the association between the atypical adenomatous hyperplasia (AAH)-adenocarcinoma in situ sequence of the lung and endoplasmic reticulum-stress responders such as ATF6, XBP1, and GRP78. Using stored tissues, we examined (i) the percentage of a splicing form (active form) of XBP1 messenger RNA in normal lung tissue (NLT) and adenocarcinoma (ACA; using reverse-transcription polymerase chain reaction); (ii) ATF6 and GRP78 protein expressions in NLT and ACA (using Western blotting analysis); (iii) ATF6, XBP1, and GRP78 protein expressions in NLT, AAH, and ACA, including some adenocarcinoma in situ (using immunohistochemistry); and (iv) the incidence of nuclear translocation of the 3 proteins in these lesions. The percentage of the splicing form of XBP1 messenger RNA showed a borderline difference between NLT and ACA (P = .068). In the Western blotting analysis, the nuclear fractions of ATF6 (including the active form) and GRP78 proteins were higher in ACA than in NLT. In the immunohistochemistry, the values obtained for the incidence of the nuclear translocation of ATF6, XBP1, and GRP78 proteins were as follows, respectively: 13.3%, 2.2%, and 0.5% in low-grade AAH; 37.9%, 2.3%, and 2.2% in high-grade AAH; and 47.2%, 10.6%, and 4.4% in ACA. A significant difference was detected between low-grade AAH and ACA for ATF6. In terms of nuclear translocation, high-grade AAH seemed intermediate between low-grade AAH and ACA. These results support endoplasmic reticulum-stress responses, such as nuclear translocation of these 3 proteins (including their active forms), being in parallel with the progression of the adenoma-carcinoma sequence in the lung.

Lobectomy Is Associated with Better Outcomes than Sublobar Resection in Spread through Air Spaces (STAS)-Positive T1 Lung Adenocarcinoma: A Propensity Score-Matched Analysis.

INTRODUCTION: Spread through air spaces (STAS) is a form of invasion wherein tumor cells extend beyond the tumor edge within the lung parenchyma. In lung adenocarcinoma (ADC), we investigated the (1) association between STAS and procedure-specific outcomes (sublobar resection and lobectomy), (2) effect of surgical margin-to-tumor diameter ratio in STAS-positive patients, and (3) potential utility of frozen sections (FSs) for detecting STAS intraoperatively. METHODS: We investigated 1497 patients who underwent lobectomy (n = 970) or sublobar resection (n = 527) for T1N0M0 lung ADC after propensity score matching. Outcomes were analyzed by using a competing risks approach. The effect of margin-to-tumor ratio on recurrence pattern (locoregional and distant) was investigated in patients who underwent sublobar resection. Five pathologists evaluated the feasibility of intraoperatively identifying STAS by using FSs (sensitivity, specificity, and interrater reliability). RESULTS: On multivariable analysis after propensity score matching (349 pairs/procedure), sublobar resection was significantly associated with recurrence (subhazard ratio = 2.84 [p < 0.001]) and lung cancer-specific death (subhazard ratio = 2.63 [p = 0.021]) in patients with STAS but not in those without STAS. Patients with STAS who underwent sublobar resection had a higher risk of locoregional recurrence regardless of margin-to-tumor ratio (for a margin-to-tumor ratio of ≥1 versus <1, the 5-year cumulative incidence of recurrence rates were 16% and 25%, respectively); among patients without STAS, locoregional recurrences occurred in patients with margin-to-tumor ratio lower than 1 (a 5-year cumulative incidence of recurrence rate of 7%). The sensitivity and specificity for detecting STAS by use of FSs were 71% and 92%, with substantial interrater reliability (Gwet's AC1, 0.67). CONCLUSIONS: In patients with T1 lung ADC with STAS, lobectomy was associated with better outcomes than sublobar resection was. Pathologists can recognize STAS on FSs.

Implications of the Eighth Edition of the TNM Proposal: Invasive Versus Total Tumor Size for the T Descriptor in Pathologic Stage I-IIA Lung Adenocarcinoma.

INTRODUCTION: The eighth edition of the TNM staging system included the proposal that the T descriptor be determined according to the invasive component, excluding lepidic component, for nonmucinous lung adenocarcinomas. We sought to conduct a clinicopathologic comparative analysis of the newly proposed classification using invasive size versus total tumor size. METHODS: Patients who underwent lung resection for primary lung adenocarcinoma with pathologic stage (p-Stage) I-IIA (based on total size [t]) were reviewed (n = 1704). Pathologic invasive size was measured, and tumors were reclassified using invasive size (i). Cumulative incidence of recurrence and lung cancer-specific cumulative incidence of death were analyzed using a competing-risks approach. Prognostic discrimination by p-Stage(t) and p-Stage(i) was evaluated using a concordance index (C-index). RESULTS: The use of invasive size resulted in downstaging in 377 of 1704 patients (22%), with twice as many patients with p-Stage IA1 (IA1[i] versus IA1[t]: 389 [23%] versus 195 [11%]). However, outcomes were similar between the two groups (IA1[i] versus IA1[t]: 5-year cumulative incidence of recurrence, 11% versus 13%; 5-year lung cancer-specific cumulative incidence of death, 5% versus 7%). Prognostic discrimination by p-Stage(i) was better than by p-Stage(t) (C-index for p-Stage[i] versus p-Stage[t]: recurrence, 0.614 versus 0.593; lung cancer-specific death, 0.634 versus 0.621). CONCLUSIONS: When invasive size, rather than total size, was used for the T descriptor, a larger number of patients were classified with a favorable prognosis (p-Stage IA1) and better prognostic discrimination of p-Stage I-IIA nonmucinous lung adenocarcinomas was achieved.

Histologic subtyping in pathologic stage I-IIA lung adenocarcinoma provides risk-based stratification for surveillance.

BACKGROUND: We hypothesize that recurrence hazard following resection for stage I-IIA lung adenocarcinoma (ADC) varies according to histologic subtype, which may provide risk stratification for surveillance better than the current uniform follow-up protocol. RESULTS: Presence (≥5%) of high-grade histologic subtypes (MIP and/or SOL) was associated with a significantly higher recurrence hazard: (1) presence of either MIP or SOL was associated with a significant increase in recurrence hazard during the first two years after surgery; (2) presence of SOL was associated with an increase in recurrence hazard-in particular, distant recurrence hazard-during the first year after surgery; (3) absence of high-grade subtypes (515/1,572 patients) was associated with a very low recurrence hazard (<2% risk/year) during the first ten years after surgery. METHODS: All hematoxylin and eosin-stained tumor slides from pathologic stage I-IIA lung ADC (n = 1572) were reviewed for quantification of the percentage of each histological subtype. Recurrence hazard was estimated using the Kernel-Epanechnikov smoothing procedure. The association between recurrence hazard and high-grade histologic subtypes (micropapillary [MIP] and solid [SOL]) was assessed. CONCLUSIONS: Our findings suggest that histologic subtyping has utility for identifying recurrence hazard for surgically resected stage I-IIA lung ADC patients and provide rationale for establishing risk-based surveillance.

Expressions of Thyroid Transcription Factor-1, Napsin A, p40, p63, CK5/6 and Desmocollin-3 in Non-Small Cell Lung Cancer, as Revealed by Imprint Cytology Using a Malinol-Based Cell-Transfer Technique.

BACKGROUND: The introduction of new therapies has made it important to differentiate between adenocarcinoma and squamous cell carcinoma. To allow the use of various immunocytochemical stains on limited materials, we tried transferring cells from a given smear to multiple slides. Using touch-preparation samples of 215 surgically resected non-small cell lung carcinomas of confirmed histologic classification (adenocarcinoma,n = 101; squamous cell carcinoma,n = 114), we performed immunocytochemistry for thyroid transcription factor-1, napsin A, p40, p63, CK5/6 and desmocollin-3, and compared cytologic staining results with the corresponding resection. METHODS: We examined: (a) the expressions of the above 6 antibodies on cells transferred from touch imprints of resected specimens, the extent of staining being considered positive if more than 5% of the area was stained, and (b) the sensitivity, specificity, positive predictive value and negative predictive value for each antibody. RESULTS: The histologic corresponding rate with Papanicolaou staining was only 73%. Regarding the differentiation of adenocarcinoma from squamous cell carcinoma, the sensitivity and specificity for napsin A in adenocarcinoma were 80 and 97%, respectively, while those for p40 in squamous cell carcinoma were 84 and 98%, respectively. CONCLUSION: The immunocytochemical expressions of napsin A and p40 in imprint cytology seem to be of great utility for the accurate histological differentiation of lung cancers.