To optimize a receptor-mediated and cell-selective gene transfer with polyethyleneimine (PEI)-based vector, we synthesized three galactosylated PEIs (Gal-PEI) with different molecular weights (PEI(1800), PEI(10,000), and PEI(70,000)) and investigated their potential as a targetable vector to asialoglycoprotein receptor-positive cells. All PEI derivatives formed complexes with plasmid DNA (pDNA), whereas the particle size of the complex became smaller on increasing the molecular weight of PEI. Transfection efficiency in HepG2 cells with PEI was highest with PEI(1800); efficiency was next highest with PEI(10,000), although the cellular association was similar. After galactosylation, Gal(19)-PEI(10,000)/pDNA and Gal(120)-PEI(70,000)/pDNA showed considerable agglutination with a galactose-recognizing lectin, but Gal(9)-PEI(1800) did not, suggesting that galactose units on the Gal(9)-PEI(1800)-pDNA complex are not sufficiently available for recognition. Gal(19)-PEI(10,000)-pDNA and Gal(120)-PEI(70,000)-pDNA complexes showed galactose-inhibitable transgene expression in HepG2 cells. Transfection efficiency was greatest with Gal(19)-PEI(10,000)/pDNA, a result that highlights the importance of obtaining a balance between the cytotoxicity and the transfection activity, both of which are found to be a function of the molecular weight of PEI. After intraportal injection, however, Gal(153)-PEI(70,000)/pDNA having a low N/P ratio was most effective, suggesting that additional variables, such as the size of the complex, are important for in vivo gene transfer to hepatocytes.

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Poly(vinyl alcohol) (PVA) of various molecular weight (MW=10,560-116,600) was successfully labeled with fluorescein isothiocyanate isomer I (FITC) according to the method of de Belder and Granath. A high-performance size-exclusion chromatographic procedure was developed for the quantitative analysis of FITC-labeled poly(vinyl alcohol) (F-PVA) in biological samples. F-PVA (80 K) disappeared slowly from the blood circulation according to the first-order kinetics (t1/2=7 h) after intravenous injection to rats. A dose-independent behavior of F-PVA (80 K) was observed in the blood circulation, in the tissue distribution and in the urinary and fecal excretions. This suggested that PVAs are eliminated exclusively by the mechanisms that do not involve saturable transport processes. Furthermore, it was found that PVAs are very stable in the body because no degradation product was detected in the urine and feces. 125I-labeled poly(vinyl alcohol) (125I-PVA) was prepared by introducing tyramine residues to the hydroxyl groups of PVA molecules by the 1,1'-cabonyldiimidazole (CDI) activation method. 125I-PVA (80 K) was retained in the blood circulation for several days after intravenous injection to mice. Although the tissue distribution of PVAs was small, a significant accumulation into the liver and the spleen was observed. Fluorescence microscopic examination of paraffin section of the liver revealed that F-PVA (80 K) was endocytosed by the liver parenchymal cells. 125I-PVA (80 K) captured by liver was slowly transported via the bile canaliculi and gall bladder to the intestine and excreted in the feces. It was suggested, therefore, a long time is necessary for 125I-PVA (80 K) to be excreted perfectly from the body.

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Downregulation of lamin B1 has been recognized as a crucial step for development of full senescence. Accelerated cellular senescence linked to mechanistic target of rapamycin kinase (MTOR) signaling and accumulation of mitochondrial damage has been implicated in chronic obstructive pulmonary disease (COPD) pathogenesis. We hypothesized that lamin B1 protein levels are reduced in COPD lungs, contributing to the process of cigarette smoke (CS)–induced cellular senescence via dysregulation of MTOR and mitochondrial integrity. To illuminate the role of lamin B1 in COPD pathogenesis, lamin B1 protein levels, MTOR activation, mitochondrial mass, and cellular senescence were evaluated in CS extract (CSE)–treated human bronchial epithelial cells (HBEC), CS-exposed mice, and COPD lungs. We showed that lamin B1 was reduced by exposure to CSE and that autophagy was responsible for lamin B1 degradation in HBEC. Lamin B1 reduction was linked to MTOR activation through DEP domain–containing MTOR-interacting protein (DEPTOR) downregulation, resulting in accelerated cellular senescence. Aberrant MTOR activation was associated with increased mitochondrial mass, which can be attributed to peroxisome proliferator-activated receptor γ coactivator-1β–mediated mitochondrial biogenesis. CS-exposed mouse lungs and COPD lungs also showed reduced lamin B1 and DEPTOR protein levels, along with MTOR activation accompanied by increased mitochondrial mass and cellular senescence. Antidiabetic metformin prevented CSE-induced HBEC senescence and mitochondrial accumulation via increased DEPTOR expression. These findings suggest that lamin B1 reduction is not only a hallmark of lung aging but is also involved in the progression of cellular senescence during COPD pathogenesis through aberrant MTOR signaling.

Our previous study showed that tumor budding is a significant indicator of a poor prognosis in lung squamous cell carcinoma patients. Tumor budding-positive (Bud(+)) cases of lung squamous cell carcinoma (SqCC) showed locally aggressive growth, and the positivity was a useful indicator of the lymph node status and prognosis. The present study focused on the clinicopathologic significance of laminin-5γ2 chain expression for local aggressiveness in lung SqCC. Laminin-5γ2 chain immunohistochemical stains in tissue samples were divided into three distinct types: basement membrane (B type; laminin-5γ2 present in basement membrane), cytoplasmic (C type; laminin-5γ2 present in intracellular matrix), and invasive front (F type; laminin-5γ2 present in cytoplasm, and strongly in part of peripheral nest). The F type was more common in Bud(+) cases than tumor budding-negative (Bud(−)) cases; B and C types were less common in Bud(+) cases (P < 0.001). The F type was more closely associated with decreased overall survival than the B and C types (P < 0.001 for both). Univariate analysis showed that the F type could be used to predict tumor size, lymph node metastasis, lymphatic invasion, tumor infiltrative patterns, tumor budding, and laminin-5γ2 chain staining. Multivariate analysis showed that laminin-5γ2 chain staining and tumor budding could be used to predict patient mortality (P < 0.001 and P = 0.005, respectively). The overall survival rate after curative resection was lower in patients with the

Localized malignant pleural mesothelioma (LMPM) is a rare tumor; previously only 52 cases have been reported in the English literature. This type of tumor should be distinguished from diffuse malignant pleural mesothelioma, because a good outcome may be obtained by surgical resection. We report a case of LMPM which grew rapidly within 1 year. Surgical resection was performed, and at present, 6 months since the operation, the patient remains free of the disease.

Lung cancer has the highest mortality rate among all cancers in most developed countries. The number of elderly patients with lung cancer has been increasing, reflecting the global increase in aging population. Therefore, standard chemotherapeutic regimens for elderly patients with lung cancer need to be established. However, the effectiveness of chemotherapy in elderly patients with advanced non-small-cell lung cancer remains controversial because they are often excluded from clinical trials. Some clinical trials have shown that the therapeutic benefit of a third-generation anticancer drug alone was superior to best supportive care. In contrast, platinum-doublet was superior only in terms of overall survival and progression-free survival, and other trials reported an increased rate of treatment-related death in the elderly patients. In recent years, some novel treatment modalities for lung cancer have been developed and shown to significantly improve the therapeutic outcomes, including targeted therapy for lung cancer harboring driver mutation, combination therapy of angiogenesis inhibitor and cytotoxic agents, and immune checkpoint inhibitor. Although several clinical trials with these agents have shown favorable outcome regardless of age, their safety in the elderly patients has not been established. Herein, we discuss the current clinical status and future prospects in elderly patients with lung cancer.