Conformational change in ricin toxin A-Chain: A critical factor for inhibitor binding to the secondary pocket.

Ricin toxin A-chain (RTA), a toxic protein from Ricinus communis, inactivates ribosomes to induce toxicity. The active site of RTA consists of two binding pockets. Many studies have focused on developing RTA inhibitors that can simultaneously bind to these critical pockets; however, almost all the inhibitors developed so far interact with only one pocket. In the present study, we discovered that pterin-7-carboxamides with aromatic l-amino acid pendants interacted with the active site of the enzyme in a 2-to-1 mode, where one inhibitor molecule bound to the primary pocket and the second one entered the secondary pocket in the active site of RTA. X-ray crystallographic analysis of inhibitor/RTA complexes revealed that the conformational changes of Tyr80 and Asn122 in RTA were critical for triggering the entry of inhibitor molecules into the secondary pocket of the RTA active site.

Mutations of the EGFR, K-ras, EML4-ALK, and BRAF genes in resected pathological stage I lung adenocarcinoma.

BACKGROUND AND PURPOSE: The EGFR, K-ras, EML4-ALK, and BRAF genes are oncogenic drivers of lung adenocarcinoma. We conducted this study to analyze the mutations of these genes in stage I adenocarcinoma. METHODS: The subjects of this retrospective study were 256 patients with resected stage I lung adenocarcinoma. We analyzed mutations of the EGFR, K-ras, and BRAF genes, and the EML4-ALK fusion gene. We also assessed disease-free survival (DFS) to evaluate the prognostic value and overall survival (OS) to evaluate the predictive value of treatment after recurrence. RESULTS: Mutations of the EGFR, K-ras, EML4-ALK, and BRAF genes were detected in 120 (46.8 %), 14 (5.5 %), 6 (2.3 %), and 2 (0.8 %) of the 256 tumors. Two tumors had double mutations (0.8 %). The incidence of EGFR mutations was significantly higher in women than in men. The EML4-ALK fusion gene was detected only in younger patients. The DFS and OS of the K-ras mutant group were significantly worse than those of the EGFR mutant group, the EML4-ALK fusion gene group, and the wild-type group. Six of the seven patients with the EML4-ALK fusion gene are still alive without recurrent disease. CONCLUSIONS: In patients with stage I adenocarcinoma, mutation of the K-ras gene was a poor prognostic factor for recurrence. The presence of a mutation of the EGFR or EML4-ALK gene was not a prognostic factor.

Increase of bone morphogenetic protein-7 expressing pulmonary resident cells in pneumonectomized rats.

PURPOSE: Compensatory lung growth (CLG) is recognized in rodents subjected to major pulmonary resection; however, the source of cells constituting regenerated tissues during the CLG is still unknown. We investigated the differentiation of lung resident cells and the participation of bone marrow (BM)-derived cells in the remnant lung of pneumonectomized rats. METHODS: After left pneumonectomy, the right remnant lung of Wistar rats was subjected to morphologic and molecular experiments at several time points. We studied the expression of bone morphogenic protein 7 (BMP-7), an accelerator of epithelial differentiation, based on the gene expression profile data of the remnant lung. Next, we evaluated the presence of GFP-positive cells in the remnant lung of Wistar rats that had received BM transplantation from green fluorescent protein (GFP) gene-transgenic Wistar rats prior to left pneumonectomy. RESULTS: We observed progression of emphysematous change, modulation of gene expression profile, and proliferating cellular nuclear antigen-positive cells in the alveoli of the remnant lungs. BMP-7 protein positive cells were detected in the alveolar septa, which increased significantly over time with the progression of emphysematous change. No bone marrow-derived cells were detected in the right remnant lung of the GFP-BM transferred rats by fluorescence microscopy, immunohistochemistry, or polymerase chain reaction at any time. CONCLUSION: Lung resident cells appear to contribute to CLG, possibly via a trans-differentiation pathway.

Mutations of the EGFR and K-ras genes in resected stage I lung adenocarcinoma and their clinical significance.

PURPOSE: This study retrospectively assessed the mutations of the epidermal growth factor receptor (EGFR) and K-ras genes and their clinical significance in patients with resected stage I adenocarcinomas. METHODS: A total of 354 patients with resected lung adenocarcinomas were included, and 256 patients with stage I disease were analyzed for the prognostic and predictive value of these mutations. RESULTS: Mutations of EGFR and K-ras genes were detected in 149 (41.1 %) and 23 (6.4 %) of all tumors, and in 122 (47.6 %) and 14 (5.5 %) of stage I tumors, respectively. There were no significant differences in the disease-free survival (DFS) and overall survival (OS) between the EGFR-mutant and wild-type groups. However, the DFS and OS were significantly shorter in patients with K-ras mutations than in those without (5-year DFS: 50.8 vs. 76.9 %, 5-year OS: 70.0 vs. 86.6 %, p < 0.01). A multivariate analysis showed that K-ras mutations were an independent poor prognostic factor. Twenty-four of the 41 patients with recurrent disease after surgery were treated with an EGFR-TKI. Fifteen EGFR-mutant patients treated with an EGFR-TKI had a better prognosis than did the nine EGFR-wild-type patients. CONCLUSION: The presence of an EGFR gene mutation was a predictive factor for the response to EGFR-TKI treatment in patients with resected stage I adenocarcinoma, but was not a prognostic factor. The presence of a K-ras gene mutation was a poor prognostic factor.

Regression of thymoma associated with a multilocular thymic cyst: report of a case.

A 28-year-old male was diagnosed with acute pericarditis after presenting with acute chest pain, fever and an abnormality in an electrocardiogram. No symptoms suggestive of myasthenia gravis were observed. Although the symptoms were alleviated by antibiotics, computed tomography (CT) showed an anterior mediastinal mass with bilateral pleural effusion. He was, therefore, diagnosed with thymoma and referred to our hospital. Surgery was performed, since the pleural effusion disappeared. The pathological examination revealed the mass to be a type B2 thymoma classified as pathological stage I (Masaoka's classification) with a multilocular thymic cyst.

Correction: Pterin-based small molecule inhibitor capable of binding to the secondary pocket in the active site of ricin-toxin A chain.

[This corrects the article DOI: 10.1371/journal.pone.0277770.].

Results of a surgical resection of pulmonary metastasis from hepatocellular carcinoma: prognostic impact of the preoperative serum alpha-fetoprotein level.

PURPOSE: Pulmonary metastasis is the most common type of extrahepatic recurrence of hepatocellular carcinoma (HCC). The outcome of pulmonary metastasectomy of HCC has not yet been thoroughly investigated. The outcomes of surgical treatment of pulmonary metastases from HCC were reviewed in order to analyze the postoperative survival and the relevant prognostic factors. METHODS: This study retrospectively reviewed 20 patients who underwent pulmonary metastasectomy from an HCC between 1990 and 2007 at two institutions. The surgical outcome was evaluated by both the overall survival and cancer-specific survival after pulmonary resection. The association between various clinico-pathological factors and the survival outcome was analyzed. RESULTS: The overall survival rate after the initial pulmonary metastasectomy was 46.9% at 5 years, and the cancer-specific 5-year survival rate was 63.2%. One patient died of surgery-related events 19 days after the pulmonary resection. The preoperative AFP (alpha-fetoprotein) level was found to be a significant prognostic factor for both overall and cancer-specific survival for patients undergoing pulmonary metastasectomy. Both the overall and cancer-specific survival rates were significantly worse for the patients with AFP ≥ 500 ng/ml in comparison to those with AFP < 500 ng/ml (p < 0.05). No other factors were associated with the survival after pulmonary metastasectomy. CONCLUSION: The serum level of AFP might be a valuable predictor for the outcome of pulmonary metastasectomy required for metastasis of HCC.

Pterin-based small molecule inhibitor capable of binding to the secondary pocket in the active site of ricin-toxin A chain.

The Ricin toxin A chain (RTA), which depurinates an adenine base at a specific region of the ribosome leading to death, has two adjacent specificity pockets in its active site. Based on this structural information, many attempts have been made to develop small-molecule RTA inhibitors that simultaneously block the two pockets. However, no attempt has been successful. In the present study, we synthesized pterin-7-carboxamides with tripeptide pendants and found that one of them interacts with both pockets simultaneously to exhibit good RTA inhibitory activity. X-ray crystallographic analysis of the RTA crystal with the new inhibitor revealed that the conformational change of Tyr80 is an important factor that allows the inhibitors to plug the two pockets simultaneously.

[Interstitial pneumonitis].

The risk management of interstitial pneumonitis in cancer chemotherapy not only involves an adverse event by an anticancer drug, but there are four steps with the incidence of interstitial pneumonitis: 1 ) the time before chemotherapy treatment, selection of chemotherapy regimens and patients, 2 ) the time chemotherapy treatment is performed, 3 ) the time during following-up, 4 ) the time when interstitial pneumonitis occurs. It is necessary to decrease the risk of interstitial pneumonitis by several steps, cooperating with an entire medical staff.

Prospective observational study of nutritional/immunologic indices as predictive biomarkers for the response to anti-PD-1 drugs in non-small cell lung cancer (ICI-PREDICT study).

Immune checkpoint inhibitors (ICIs) targeting programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) have markedly improved the prognosis of many patients with advanced non-small cell lung cancer (NSCLC). However, the relationship between the patient's nutritional/immunologic status and the outcomes of ICI treatment remains unclear. In previous retrospective studies, we reported that the controlling nutritional status (CONUT) score, skeletal muscle area, and neutrophil-to-lymphocyte ratio were independent predictors of the response of NSCLC patients to anti-PD-1 drugs. The aim of this prospective multi-center study is to investigate the clinical impact of pre-treatment nutritional/immunologic indices and early post-treatment changes in the indices on treatment outcomes in advanced NSCLC. The main inclusion criteria are: (1) stage IV NSCLC, or stage III NSCLC not applicable for definitive chemoradiotherapy; (2) treatment with ICIs (monotherapy or combined with chemotherapy) as first-line therapy; and (3) available data on PD-L1 expression on tumor cells. A total of 300 patients will be enrolled prospectively. Enrollment will begin in 2020 and the final analyses will be completed by 2025.

Expression of an X-family DNA polymerase, pol lambda, in the respiratory epithelium of non-small cell lung cancer patients with habitual smoking.

DNA polymerase lambda, pol lambda, is a eukaryotic member of the X-family DNA polymerases that is involved in two modes of DNA repair, i.e. base excision repair (BER) or non-homologous end joining (NHEJ). Using immunohistochemical approaches, we have observed pol lambda expression in human tissues, particularly in the respiratory system of lung cancer patients. pol lambda proteins were distributed in the nuclei of the epithelial cells in the bronchi, bronchioles and alveoli. Intriguingly, the level of pol lambda expression in the bronchiolar epithelia significantly correlated with the amount of habitual smoking in the individuals. Conversely, pol lambda expression in cancer tissues did not correlate with the smoking status of the patients. Pol lambda expression was sometimes discrepant between the tumor tissues and adjacent bronchioles. More importantly, tumors without pol lambda expression that occurred in heavy smokers significantly tended to be at an advanced clinical stage. Pol lambda may thus be involved in the DNA repair processes counteracting DNA damage caused by tobacco smoke in the respiratory system.

Prognostic impact of the Controlling Nutritional Status score in patients with non-small cell lung cancer treated with pembrolizumab.

BACKGROUND: Pembrolizumab, an anti-programmed cell death-1 (PD-1) monoclonal antibody, has been shown to yield a durable response and significant survival benefit in some non-small cell lung cancer (NSCLC) patients. Recent studies have shown that the Controlling Nutritional Status (CONUT) score, a novel nutritional index, can be useful for predicting the prognosis in some malignancies. However, its usefulness in predicting the clinical outcome of immune-checkpoint inhibitor (ICI) treatment in patients with NSCLC has not been clarified. The aim of this study was to investigate the clinical significance of the CONUT score in NSCLC patients treated with pembrolizumab. METHODS: We conducted a retrospective analysis of the clinical data of 32 patients with advanced NSCLC who received pembrolizumab monotherapy. A cut-off CONUT score of 2 was used to categorize patients into low and high CONUT groups. We evaluated the relation between the clinicopathological factors including CONUT score and neutrophil-to-lymphocyte ratio (NLR) and the prognosis. RESULTS: Twenty-two patients were classified into the low CONUT score group, while 10 were classified into the high CONUT score group. In the univariate and multivariate analyses, the number of prior treatments and the CONUT score were found to independently predict progression-free survival (PFS) (P<0.05), while the CONUT score as well as NLR was an independent prognostic factor for overall survival (P<0.05). In addition, in patients who received pembrolizumab as a first-line treatment, a high CONUT score was associated with a significantly worse PFS and overall survival in comparison to a low CONUT score. CONCLUSIONS: The CONUT score has potential application as a predictor of the therapeutic effect and the prognosis of NSCLC patients treated with pembrolizumab. Our findings suggest that in addition to the programmed cell death ligand 1 expression level, the CONUT may also be a useful indicator for selecting NSCLC patients who may benefit from ICI treatment.

Short progression-free survival of ALK inhibitors sensitive to secondary mutations in ALK-positive NSCLC patients.

BACKGROUND: Most non-small cell lung cancer (NSCLC) patients relapse on anaplastic lymphoma kinase-tyrosine kinase inhibitor (ALK-TKI) therapy because of acquired resistance. Rebiopsy is recommended to provide optimal therapy after relapse for some ALK-TKI therapies; however, little clinical data exists on the clinical efficacy of ALK-TKI tailored to secondary mutation. METHODS: A retrospective study was conducted to analyze the patterns of ALK-TKI treatment and clinical outcomes, including progression free survival (PFS), of ALK-positive NSCLC patients who received rebiopsy. Based on the rebiopsy results, secondary mutations in the ALK gene that were shown to be associated with the efficacy of ALK-TKI therapy in the preclinical or clinical setting were defined as "sensitive mutations (SM)". RESULTS: Among 71 patients who received ALK-TKI for NSCLC at our institution, 20 patients received rebiopsy, and secondary SM were found in eight patients. The objective response rate (ORR) of the cases with SM who received ALK-TKI therapy was 88.9%, while the ORR of the patients without SM who received ALK TKI or chemotherapy was 20.0%; however, the PFS of the patients with SM was relatively short (with SM vs. without SM: 5.6 months vs. 5.1 months). CONCLUSIONS: The selection of ALK-TKI based on the rebiopsy result was associated with a high ORR and relatively short PFS. The mechanism responsible for the short PFS of sensitive ALK-TKI to secondary mutation should be clarified.

Expression of mismatch repair proteins, hMLH1/hMSH2, in non-small cell lung cancer tissues and its clinical significance.

BACKGROUND: hMLH1 and hMSH2 have been implicated to be involved in the DNA mismatch repair (MMR) system. The purpose of this study is to investigate the expression of hMLH1 and hMSH2 DNA MMR proteins in non-small cell lung cancer (NSCLC) tissue and to elucidate their clinical significance. METHODS: The hMLH1 and hMSH2 protein expression was evaluated by immunohistochemistry for a consecutive series of 113 NSCLC patients. The expressions of each protein were examined for an association with the clinicopathological variables, including genetic alterations analyzed by high resolution fluorescent microsatellite analysis. RESULTS: Regarding the hMLH1 expression, the MSI-positive patients showed significantly lower scores than the MSI-negative patients. For hMSH2 expression, the patients with a 20 or higher pack-year index (PYI) showed significantly higher scores than the patients with a PYI less than 20. The expression status of proteins did not affect both the disease free and overall survival of the patients. No significant correlation was observed among the scores for the proteins. CONCLUSIONS: The expressions of hMLH1 and hMSH2 are independently regulated and play different roles in NSCLC. The genetic instability is possibly due to the reduced expression of hMLH1 protein, and hMSH2 expression is associated with smoking status.

Relationship between the loss of heterozygosity and tobacco smoking in pulmonary adenocarcinoma.

A loss of heterozygosity (LOH) is a major cause of lung carcinogenesis, and it is considered to be related to tobacco smoking in central type lung cancer. We investigated the relationship between LOH in lung adenocarcinoma and tobacco smoking. In a consecutive series of 50 patients with lung adenocarcinoma who underwent a surgical resection, cancer tissue specimens and corresponding normal peripheral lung and central bronchial tissue specimens were analyzed for LOH at the regions of D3S1234 (FHIT), D3S1300 (FHIT), D9S171 (CDKN2), and D17S796 (p53) by polymerase chain reaction using four fluorescence-labeled dinucleotide markers. To examine how cells are influenced by smoking, the A549 cell line was exposed to benzo[a]pyrene (B[a]P) for 24 weeks and then was subjected to the above analysis. The LOH in cancer tissue was thus detected in four (17%) patients at D3S1234, six (14%) at D3S1300, and seven (18%) at D17S796, but no LOH was detected in any normal tissue specimens. The incidence of LOHs in cancer tissue specimens from active smokers was 21% at D3S1234, 11% at D3S1300, and 19% at D17S796, whereas that of LOHs from nonactive smokers was 0% at D3S1234, 19% at D3S1300, and 14% at D17S796. Analyzing the relationship between the pack-year index and the presence of LOH, a significant difference was found among the active smokers. Besides, in the A549 cell line exposed to B[a]P, LOH was de novo detected in one (D2S123) of the nine regions examined. The incidence of LOH could be influenced by tobacco smoking in lung adenocarcinoma, thus suggesting the presence of an important event in the carcinogenesis of this disease.

Preoperative concurrent chemoradiotherapy of S-1/cisplatin for stage III non-small cell lung cancer.

BACKGROUND: Concurrent chemoradiotherapy using S-1 containing tegafur, an oral 5-FU prodrug, plus cisplatin has been reported to show promising efficacy against locally advanced non-small cell lung cancer with acceptable toxicity. The purpose of this study is to assess the impact of this induction treatment followed by surgery on survival for those patients. METHODS: Potentially resectable locally advanced non-small cell lung cancer patients were eligible. The concurrent phase consisted of S-1 (orally at 40 mg/m² twice a day on days 1 to 14 and 22 to 36) and cisplatin (60 mg/m² on days 1 and 22) with radiation of 40 Gy/20 fractions beginning on day 1 followed by surgical resection. RESULTS: Forty-two consecutive patients, between June 2005 and February 2011, were retrospectively analyzed. The median age was 59 (42 to 77) years, there were 34 males and 8 females, 26 cStage IIIA and 16 IIIB, each 21 adenocarcinomas and others. There were 26 partial responses and 16 stable disease cases after current induction treatment without uncontrollable toxicity. Of the 42 patients, 39 underwent surgical resection; 27 underwent a lobectomy and 12 pneumonectomies. One patient died due to thoracic empyema 65 days after surgery. The median follow-up time was 32.0 months. Three- and 5-year disease-free survival rates in all 39 resected patients were 52.0% and 44.0%, respectively, and 3- and 5-year overall survival rates were 77.4% and 61.7%, respectively. CONCLUSIONS: Concurrent chemoradiotherapy using S-1 plus cisplatin followed by surgery may provide a better prognosis for locally advanced non-small cell lung cancer patients. Further prospective clinical investigation should be required.

Signet ring cell adenocarcinoma of the lung with an EML4-ALK fusion gene mimicking mucinous (colloid) adenocarcinoma: a case report.

We herein report a case of signet ring cell adenocarcinoma of the lung with an EML4-ALK fusion gene mimicking mucinous (colloid) adenocarcinoma. A 79-year-old female presented with a pulmonary tumor located in the right lower lobe measuring 21 mm in size. A right lower lobectomy was performed. The postoperative pathological examination revealed signet ring cell carcinoma with abundant mucin pools, and a multiplex RT-PCR analysis revealed the variant 2 inversion of the EML4-ALK gene.

Effects of excision repair cross-complementation group 1 (ERCC1) single nucleotide polymorphisms on the prognosis of non-small cell lung cancer patients.

BACKGROUND: Excision repair cross-complementation group 1 (ERCC1) is the lead enzyme in the nucleotide excision repair process. Two polymorphisms of ERCC1, T19007C (rs11615) and C8092A (rs3212986), have been reported to affect both the carcinogenesis and the survival of the patients who received platinum-based chemotherapy, but the mechanism by which these polymorphisms influence the survival is unclear. In this study, we determined the function of these ERCC1 polymorphisms in the survival of NSCLC patients. METHOD: The ERCC1 T19007C and C8092A single nucleotide polymorphisms (SNPs) were evaluated in 122 Japanese non-small cell lung cancer (NSCLC) patients who underwent a complete resection and analyzed the clinicopathological significance of these SNPs. None of the patients received peri-operative platinum-based chemotherapy. The relationship between these SNPs and ERCC1 protein expression and the platinum sensitivity of the primary tumors were also examined. RESULT: Regarding T19007C SNP, the distribution of the CC, CT, and TT genotypes was 45%, 48% and 7%, respectively. As for C8092A SNP, the distribution of CC and CA genotypes was 70% and 30%, respectively. The patients with C8092A CA genotype were significantly poorer disease-free survival (DFS) and overall survival (OS) than those with the CC genotype (p=0.037 and 0.004). In addition, no relationship was observed between T19007C SNP and DFS or OS. These two SNPs also did not correlate with either ERCC1 protein expression or platinum sensitivity. CONCLUSION: The ERCC1 C8092A polymorphism may influence the NSCLC prognosis regardless of the ERCC1 protein expression and platinum sensitivity.

Benzo[a]pyrene promotes proliferation of human lung cancer cells by accelerating the epidermal growth factor receptor signaling pathway.

Smoking is an independent prognostic factor of lung adenocarcinoma. Benzo[a]pyrene (B[a]P) is one of the strongest carcinogens and it is present in both the environment and cigarette smoke. In this study, the effect of B[a]P on the proliferative activity of lung adenocarcinoma cells was investigated. A lung adenocarcinoma cell line, A549, was cultured with B[a]P for various periods, and its proliferative activity was examined by an MTS assay. To investigate the intracellular events related to the proliferative activity, the gene expression profile was investigated by a microarray analysis and a quantitative RT-PCR, and the protein expression and activation status of Akt, ERK 1/2 and the epidermal growth factor receptor (EGFR) were examined by a western blot analysis. Following the culture with B[a]P for 24 weeks, the serum-independent proliferative activity was increased. A microarray analysis revealed that a reversible upregulation of the EGFR and epiregulin genes was recognized in the B[a]P treated cells, in which the overexpression of the phosphorylated EGFR protein was also recognized. The EGFR tyrosine kinase inhibitor reduced the cellular proliferation and the level of phosphorylation of ERK1/2, which is a downstream signal of the EGFR, in the B[a]P-treated A549 cells. Moreover, the B[a]P treatment increased the mRNA expressions of the ligands for EGFR such as amphiregulin and epiregulin. B[a]P increases the proliferative potential of lung adenocarcinoma cells through the EGFR signaling pathway.

Upregulation of hypoxia-inducible factor-1alpha mRNA and its clinical significance in non-small cell lung cancer.

BACKGROUND: Hypoxia-inducible factor 1alpha (HIF-1alpha) is a transcription factor that plays an important role in tumor growth by regulating the energy metabolism and angiogenesis. We herein investigated the mRNA expression level of HIF-1alpha in non-small cell lung cancer (NSCLC) tissues to clarify the impact on the clinical aspects of NSCLC patients. EXPERIMENTAL DESIGN: HIF-1alpha mRNA derived from either a tumor or an adjacent lung tissue was quantified using quantitative reverse transcription polymerase chain reaction in 66 patients with NSCLC. The relationship between the mRNA expression level of HIF-1alpha and clinicopathological factors was investigated. RESULTS: The expression level of HIF-1alpha mRNA, which correlated with its protein level, was significantly higher in tumor tissue than in the corresponding nontumor-bearing lung tissue (4.22 x 10(4) +/- 4.99 x 10(4) versus 1.24 x 10(4) +/- 1.15 x 10(4); p < 0.001). The level of HIF-1alpha mRNA showed a significantly positive correlation with the mRNA levels of vascular endothelial growth factor and type II hexokinase in tumors (p < 0.0001 for each). In node-negative patients, high expression levels of HIF-1alpha mRNA in tumors were associated with a poor prognosis (p = 0.0401), but not in the node-positive cases. CONCLUSION: The expression of HIF-1alpha mRNA is associated with disease progression in NSCLC tissues, and is expected as a biomarker or therapeutic target.