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The primary coordination sphere of the multinuclear cofactor (Mn4CaOx) in the oxygen-evolving complex (OEC) of photosystem II is absolutely conserved to maintain its structure and function. Recent time-resolved serial femtosecond crystallography identified large reorganization of the primary coordination sphere in the S-2 to S-3 transition, which elicits a cascade of events involving Mn oxidation and water molecule binding to a putative catalytic Mn site. We examined how the crystallographic fields, created by transient conformational states of the OEC at various time points, affect the thermodynamics of various isomers of the Mn cluster using DFT calculations, with an aim of comprehending the functional roles of the flexible primary coordination sphere in the S-2 to S-3 transition and in the recovery of the S-2 state. The results show that the relative movements of surrounding residues change the size and shape of the cavity of the cluster and thereby affect the thermodynamics of various catalytic intermediates as well as the ability to capture a new water molecule at a coordinatively unsaturated site. The implication of these findings is that the protein dynamics may serve to gate the catalytic reaction efficiently by controlling the sequence of Mn oxidation/reduction and water binding/release. This interpretation is consistent with EPR experiments; g similar to 5 and g similar to 3 signals obtained after near-infrared (NIR) excitation of the S-3 state at 4 K and a g similar to 5 only signal produced after prolonged incubation of the S-3 state at 77 K can be best explained as originating from water-bound S-2 clusters (S-total = 7/2) under a S-3 ligand field, i.e., the immediate one-electron reduction products of the oxyl-oxo (S-total = 6) and hydroxo-oxo (S-total = 3) species in the S-3 state.

The aim of this review is to elucidate geometric structures of the catalytic CaMn4Ox (x = 5, 6) cluster in the Kok cycle for water oxidation in the oxygen evolving complex (OEC) of photosystem II (PSII) based on the high-resolution (HR) X-ray diffraction (XRD) and serial femtosecond crystallography (SFX) experiments using the X-ray free-electron laser (XFEL). Quantum mechanics (QM) and QM/molecular mechanics (MM) computations are performed to elucidate the electronic and spin structures of the CaMn4Ox (x = 5, 6) cluster in five states S-i (i = 0 similar to 4) on the basis of the X-ray spectroscopy, electron paramagnetic resonance (EPR) and related experiments. Interplay between the experiments and theoretical computations has been effective to elucidate the coordination structures of the CaMn4Ox (x = 5, 6) cluster ligated by amino acid residues of the protein matrix of PSII, valence states of the four Mn ions and total spin states by their exchange-couplings, and proton-shifted isomers of the CaMn4Ox (x = 5, 6) cluster. The HR XRD and SFX XFEL experiments have also elucidated the biomolecular systems structure of OEC of PSII and the hydrogen bonding networks consisting of water molecules, chloride anions, etc., for water inlet and proton release pathways in PSII. Large-scale QM/MM computations have been performed for elucidation of the hydrogen bonding distances and angles by adding invisible hydrogen atoms to the HR XRD structure. Full geometry optimizations by the QM and QM/MM methods have been effective for elucidation of the molecular systems structure around the CaMn4Ox (x = 5, 6) cluster in OEC. DLPNO-CCSD(T-0) method has been applied to elucidate relative energies of possible intermediates in each state of the Kok cycle for water oxidation. Implications of these results are discussed in relation to the blueprint for developments of artificial catalysts for water oxidation.

Osimertinib is a standard of care therapy for previously untreated epidermal growth factor receptor mutation-positive non-small cell lung cancer. However, limited data exist regarding the efficacy and safety of osimertinib as a first-line therapy for elderly patients aged 75 years or older. To assess the potential clinical benefits of osimertinib in this population, this retrospective multi-institutional observational study included 132 patients with non-small cell lung cancer (age >= 75 years), who received osimertinib as first-line treatment. The proportion of patients with 1-year progression-free survival was 65.8% (95% confidence interval 57.1-73.5). The median progression-free survival was 19.4 (95% confidence interval 15.9-23.9) months. The median overall survival was not reached (95% confidence interval 24.6-not reached). The frequency of pneumonitis was 17.4%, with a grade 3 or higher rate of 9.1%. More than two-thirds of treatment discontinuations due to pneumonitis occurred within 3 months of starting osimertinib, and the prognosis of patients with pneumonitis was unsatisfactory. Osimertinib is one of the effective first-line therapeutic options for patients aged 75 years or older; however, special caution should be exercised due to the potential development of pneumonitis.

Objectives: Limited information is available on the appropriate treatment duration of immune checkpoint inhibitors (ICIs). We aimed to identify candidates who would benefit from ICI discontinuation after one year of treatment for metastatic non-small cell lung cancer (NSCLC). Materials and methods: This retrospective multi-institutional observational study examined medical records of all consecutive patients with advanced or recurrent NSCLC, who started ICI monotherapy at 15 institutions in Japan between December 2015 and December 2017. Patients who received initial ICI therapy for >1 year without progressive disease were defined as the long-term treatment (LT) group; others were defined as the non -longterm treatment (NLT) group. Primary outcomes included the prognostic factors in the LT group, whereas secondary outcomes included efficacy of ICI rechallenge, safety, and survival outcomes in the overall population. Results: In total, 676 patients were enrolled, and 114 (16.9 %) were assigned to the LT group. The median time interval from the start of initial ICI administration to data cutoff was 34.3 months (range, 24.1 & ndash;47.8); thus, all surviving patients were followed-up for at least 2 years from the start of initial ICI. Median progression-free survival (PFS) was longer in the LT than in the NLT group (33.6 months vs. 2.7 months; p < 0.001). On multivariate analysis, significantly better PFS was associated with smoking (hazard ratio [HR]=0.36, p = 0.04), and complete response (CR; HR=uncomputable, p < 0.001) in the LT group. Thirty-seven patients (5.5 %) received ICI rechallenge, including 10 in the LT group. Among patients receiving rechallenge treatment, the median PFS was 2.2 months, with no difference between the LT and NLT groups. Conclusions: In the LT group, smoking and achieving CR were significantly associated with better PFS. Since rechallenge treatment was not effective, careful consideration is required for discontinuing ICI. However, these pro

Objectives: Patients with concomitant advanced non-small cell lung cancer (NSCLC) and interstitial lung disease (ILD) are excluded from most clinical chemotherapy trials because of the high risk of exacerbating the latter condition. This study prospectively investigated the efficacy and safety of albumin-bound paclitaxel (nab-paclitaxel) in combination with carboplatin in patients with both advanced NSCLC and ILD. Patients and methods: The enrolled patients had treatment-naive, advanced NSCLC with ILD. Patients received 100 mg/m(2) nab-paclitaxel weekly and carboplatin at an area under the concentration-time curve of 6 once every 3 weeks for 4-6 cycles. The primary endpoint was the overall response rate (ORR); secondary endpoints included toxicity, progression-free survival (PFS), and overall survival (OS). Results: Thirty-six patients were enrolled between April 2014 and September 2017. Sixteen patients (44.4%) had adenocarcinoma, 15 (41.7%) had squamous cell carcinoma (Sq), and 5 (13.9%) had non-small cell carcinoma. The median number of cycles administered were 4 (range: 1-6). The ORR was 55.6% (95% confidence interval [CI]: 39.6-70.5). The median PFS and OS were 5.3 months (95% CI: 3.9-8.2) and 15.4 months (95% CI: 9.4-18.7), respectively. A greater proportion of patients with Sq experienced improvements than did those with non-Sq: ORRs, 66.7% (95% CI: 41.7-84.8) vs. 47.6% (95% CI: 28.3-67.6) (P = 0.254); median PFS, 8.2 months (95% CI: 4.0-10.2) vs. 4.1 months (95% CI: 3.3-5.4) (HR, 0.60 [95% CI, 0.30-1.20]; P = 0.15); and median OS, 16.8 months (95% CI: 9.8 not reached) vs. 11.9 months (95% CI: 7.3-17.4) (HR, 0.56 [95% CI, 0.24-1.28]; P = 0.17). Two patients (5.6%) experienced grade >= 2 pneumonitis and 1 patient (2.8%) died. Conclusion: Weekly nab-paclitaxel combined with carboplatin showed favorable efficacy with acceptable toxicity in patients with both advanced NSCLC and ILD.

Background Delta-like protein 3 (DLL3) is a Notch ligand that has an important role in the tumorigenesis of small cell lung cancer (SCLC). Recently, rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibody-drug conjugate, has been developed for treating SCLC. DLL3 is a transcriptional target of the achaete-scute homolog-1 (ASCL1) transcription factor, which is involved in pulmonary neuroendocrine cell development. However, the relationship between DLL3 and/or ASCL1 expression and the clinical features of SCLC remains unknown, especially for early-stage resected SCLC. This study aimed to investigate the expression of DLL3 and ASCL1 in resected SCLC samples using immunohistochemical analysis. Materials and Methods We collected 95 surgically resected SCLC samples, which were formalin fixed and paraffin embedded. Immunohistochemistry staining was performed to investigate the correlation between the expression of either DLL3 or ASCL1 and clinicopathological features of study patients. Results Seventy-seven (83%) of 93 immunohistochemically evaluable samples were positive for DLL3 (expression in >= 1% of tumor cells), and DLL3-high expression (>= 75%) was observed in 44 samples (47%). Sixty-one (64%) of 95 samples were positive for ASCL1 (expression in >= 5% of tumor cells). A positive correlation was observed between DLL3 and ASCL1 expression. DLL3 and ASCL1 expression were not associated with survival in SCLC patients. DLL3 was more prevalent in patients with advanced clinical disease. Conclusion DLL3 and ASCL1 were highly expressed in patients with surgically resected SCLC. DLL3 and ASCL1 may be targets for the treatment of SCLC. Implications for Practice This article examines the relationship between delta-like protein 3 (DLL3) and achaete-scute homolog-1 (ASCL1) protein expression with the clinical features of 95 surgically resected small cell lung cancer (SCLC). DLL3 is attracting attention because rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibod

Background Delta-like protein 3 (DLL3) is a Notch ligand that has an important role in the tumorigenesis of small cell lung cancer (SCLC). Recently, rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibody-drug conjugate, has been developed for treating SCLC. DLL3 is a transcriptional target of the achaete-scute homolog-1 (ASCL1) transcription factor, which is involved in pulmonary neuroendocrine cell development. However, the relationship between DLL3 and/or ASCL1 expression and the clinical features of SCLC remains unknown, especially for early-stage resected SCLC. This study aimed to investigate the expression of DLL3 and ASCL1 in resected SCLC samples using immunohistochemical analysis. Materials and Methods We collected 95 surgically resected SCLC samples, which were formalin fixed and paraffin embedded. Immunohistochemistry staining was performed to investigate the correlation between the expression of either DLL3 or ASCL1 and clinicopathological features of study patients. Results Seventy-seven (83%) of 93 immunohistochemically evaluable samples were positive for DLL3 (expression in >= 1% of tumor cells), and DLL3-high expression (>= 75%) was observed in 44 samples (47%). Sixty-one (64%) of 95 samples were positive for ASCL1 (expression in >= 5% of tumor cells). A positive correlation was observed between DLL3 and ASCL1 expression. DLL3 and ASCL1 expression were not associated with survival in SCLC patients. DLL3 was more prevalent in patients with advanced clinical disease. Conclusion DLL3 and ASCL1 were highly expressed in patients with surgically resected SCLC. DLL3 and ASCL1 may be targets for the treatment of SCLC. Implications for Practice This article examines the relationship between delta-like protein 3 (DLL3) and achaete-scute homolog-1 (ASCL1) protein expression with the clinical features of 95 surgically resected small cell lung cancer (SCLC). DLL3 is attracting attention because rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibody-drug co

Objectives: Patients with concomitant advanced non-small cell lung cancer (NSCLC) and interstitial lung disease (ILD) are excluded from most clinical chemotherapy trials because of the high risk of exacerbating the latter condition. This study prospectively investigated the efficacy and safety of albumin-bound paclitaxel (nab-paclitaxel) in combination with carboplatin in patients with both advanced NSCLC and ILD. Patients and methods: The enrolled patients had treatment-naive, advanced NSCLC with ILD. Patients received 100 mg/m(2) nab-paclitaxel weekly and carboplatin at an area under the concentration-time curve of 6 once every 3 weeks for 4-6 cycles. The primary endpoint was the overall response rate (ORR); secondary endpoints included toxicity, progression-free survival (PFS), and overall survival (OS). Results: Thirty-six patients were enrolled between April 2014 and September 2017. Sixteen patients (44.4%) had adenocarcinoma, 15 (41.7%) had squamous cell carcinoma (Sq), and 5 (13.9%) had non-small cell carcinoma. The median number of cycles administered were 4 (range: 1-6). The ORR was 55.6% (95% confidence interval [CI]: 39.6-70.5). The median PFS and OS were 5.3 months (95% CI: 3.9-8.2) and 15.4 months (95% CI: 9.4-18.7), respectively. A greater proportion of patients with Sq experienced improvements than did those with non-Sq: ORRs, 66.7% (95% CI: 41.7-84.8) vs. 47.6% (95% CI: 28.3-67.6) (P = 0.254); median PFS, 8.2 months (95% CI: 4.0-10.2) vs. 4.1 months (95% CI: 3.3-5.4) (HR, 0.60 [95% CI, 0.30-1.20]; P = 0.15); and median OS, 16.8 months (95% CI: 9.8 not reached) vs. 11.9 months (95% CI: 7.3-17.4) (HR, 0.56 [95% CI, 0.24-1.28]; P = 0.17). Two patients (5.6%) experienced grade >= 2 pneumonitis and 1 patient (2.8%) died. Conclusion: Weekly nab-paclitaxel combined with carboplatin showed favorable efficacy with acceptable toxicity in patients with both advanced NSCLC and ILD.

Background: This study evaluated the efficacy and safety of switch maintenance erlotinib and bevacizumab after induction therapy with carboplatin/pemetrexed/bevacizumab for non-squamous non-small cell lung cancer (NSCLC) with wild-type EGFR. Methods: Enrolled patients had treatment-naive, advanced non-squamous NSCLC with wild-type EGFR. Carboplatin [area under the curve (AUC) 5.0], pemetrexed (500 mg/m2) and bevacizumab (15 mg/kg) were administered on day 1 every 3 weeks for 4-6 cycles. Maintenance therapy with erlotinib (150 mg/body) on day 1 through 21 plus bevacizumab on day 1 every 3 weeks was continued until disease progression or unacceptable toxicity. The primary endpoint was 6-month progression-free survival (PFS); secondary endpoints included overall survival (OS), overall response rate (ORR), toxicity, and quality of life (QOL). Results: Fifty-one patients were enrolled between September 2011 and June 2014. The median number of cycles for induction and maintenance therapy was 4 (range 1-6) and 4 (range 1-20). Twenty-nine patients (58%) received maintenance therapy. The 6-month PFS rate was 59.5% [95% confidence interval (CI) 45.0-72.6%]. The ORR was 48.0% (95% CI 34.8-61.5%), and disease control rate was 86.0% (95% CI 73.8-93.0%). The median PFS and OS were 6.5 months (95% CI 5.8-7.2 months) and 21.4 months (95% CI 15.9-26.9 months), respectively. Although grades ≥ 3 adverse events were observed in 33 patients (66.0%), most were hematologic; there was no febrile neutropenia. QOL was maintained throughout treatment. Conclusions: Carboplatin/pemetrexed/bevacizumab followed by erlotinib and bevacizumab maintenance showed modest efficacy and was well tolerated in non-squamous NSCLC patients with wild-type EGFR.