Background : Various mitotic events are controlled by Cdc2-cyclin B and other mitotic kinases. Aurora/ Ipl1-related mitotic kinases were proved to play key roles in mitotic progression in diverse lower organisms. Aurora-A is a mammalian counterpart of aurora/Ipl1-related kinases and is thought to be a potential oncogene. However, the regulation of aurora-A activation and the commitment of aurora-A in the progression of G2-M phase are largely unknown in mammalian cells.

Neurofibromin is a neurofibromatosis type 1 (NF1) tumor suppressor gene product with a domain that acts as a GTPase-activating protein and functions, in part, as a negative regulator of Ras. Loss of neurofibromin expression in NF1 patients is associated with elevated Ras activity and increased cell proliferation, predisposing to a variety of tumors of the peripheral and central nervous systems. We show here, using the small interfering RNA (siRNA) technique, that neurofibromin dynamically regulates actin cytoskeletal reorganization, followed by enhanced cell motility and gross cell aggregation in Matrigel matrix. NF1 siRNA induces characteristic morphological changes, such as excessive actin stress fiber formation, with elevated negative phosphorylation levels of cofilin, which regulates actin cytoskeletal reorganization by depolymerizing and severing actin filaments. We found that the elevated phosphorylation of cofilin in neurofibromin-depleted cells is promoted by activation of a Rho-ROCK-LIMK2 pathway, which requires Ras activation but is not transduced through three major Ras-mediated downstream pathways via Raf, phosphatidylinositol 3-kinase, and RalGEF. In addition, the exogenous expression of the NF1-GTPase-activating protein-related domain suppressed the NF1 siRNA-induced phenotypes. Neurofibromin was demonstrated to play a significant role in the machinery regulating cell proliferation and in actin cytoskeletal reorganization, which affects cell motility and adhesion. These findings may explain, in part, the mechanism of multiple neurofibroma formation in NF1 patients.Neurofibromatosis type 1 (NF1), 2 also called von Recklinghausen disease, is autosomal dominant and one of the most common inherited disorders, affecting 1 in 3500 individuals (1). The phenotype of NF1 is highly variable, with several organ systems being affected, including bones, skin, irises, and central and peripheral nervous systems. The disease commonly manifests with "café au lait" macules in the skin, iris Lisch nodules, and learning disability (2, 3). The hallmark of NF1 is benign tumors that develop in the peripheral nervous system accompanied by an increased risk of malignancies.The NF1 gene lies on chromosome 17q11.2 and encodes a large 2818-amino acid protein, termed neurofibromin. Sequence analysis of neurofibromin revealed that a region centered around the 360 amino acids encoded by the NF1 gene shows significant homology to the known catalytic domains of mammalian Ras GTPase-activating protein (p120GAP), which interacts with Ras and promotes hydrolysis of Rasbound GTP (active form) to GDP (inactive form), resulting in inactivation of the Ras protein. Accordingly, loss and/or mutations of neurofibromin elevate Ras activity and are followed by activation of various Ras effectors. Ras activation has been considered to be the causative event for tumor formation and other clinical manifestations in NF1 patients (2, 3).Recent studies have suggested that neurofibromin has additional functions besides regulating cell proliferation ...

While mRNA vaccines against SARS-CoV-2 are exceedingly effective in preventing symptomatic infection, their immune response features remain to be clarified. In the present prospective study, 225 healthy individuals in Japan, who received two BNT162b2 doses, were enrolled. Correlates of BNT162b2-elicited SARS-CoV-2-neutralizing activity (50% neutralization titer: NT50; assessed using infectious virions) with various determinants were examined and the potency of sera against variants of concerns was determined. Significant rise in NT50s was seen in sera on day 28 post-1st dose. A moderate inverse correlation was seen between NT50s and ages, but no correlation seen between NT50s and adverse effects. NT50s and SARS-CoV-2-S1-binding-IgG levels on day 28 post-1st dose and pain scores following the 2nd dose were greater in women than in men. The average half-life of NT50s was ~ 68 days, and 23.6% (49 out of 208 individuals) failed to show detectable neutralizing activity on day 150. While sera from elite-responders (NT50s > 1,500: the top 4% among the participants) potently to moderately blocked all variants of concerns examined, some sera with low NT50s failed to block the B.1.351-beta strain. Since BNT162b2-elicited immunity against SARS-CoV-2 is short, an additional vaccine or other protective measures are needed.

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The epidermal growth factor receptor (EGFR) variant type III (variously called EGFRvIII, de2-7 EGFR or ∆ ∆ ∆ ∆EGFR) has an in-frame deletion of the extracellular domain and is found in numerous types of human tumors. Since EGFRvIII has been reported to be tumorspecific and has oncogenic potential, it is being investigated as a potential therapeutic target. Because the cell-specific expression of EGFRvIII in lung has not been well documented, we examined the expression of EGFRvIII in 76 non-small cell lung cancers (NSCLCs) and 10 non-neoplastic lung tissues by immunohistochemistry using a new monoclonal antibody specific for this variant receptor. We found a higher incidence (30 of 76, 39%) of enhanced EGFRvIII expression in NSCLC than previously described. Interestingly, the presence of EGFRvIII was also observed in several normal tissue components of lung (e.g., normal bronchial epithelium). Given the high prevalence of EGFRvIII in NSCLC, a newly he epidermal growth factor receptor (EGFR) has been implicated in the pathogenesis of several human tumors, including those of the brain, breast, lung and head and neck, and is being actively studied as a target for therapy.1-6) Overexpression of the EGFR in multiple human tumors has been extensively documented, and it has become increasingly apparent that alterations within the EGFR gene may be as important as overexpression for oncogenic effect. 7,8) Several different types of alterations that result in aberrant protein products have been identified. [9][10][11] The most common variant, EGFRvIII (also referred to as ∆EGFR, or de2-7 EGFR), is characterized by an inframe deletion of exons 2-7 of the coding sequence, which has been found to be generated by gene rearrangement or aberrant mRNA splicing. [12][13][14][15] This deletion removes 267 amino acids from the extracellular domain of the normal EGFR, creating a unique epitope at the fusion junction. A number of functional differences between EGFRvIII and EGFR have been characterized. [15][16][17][18] Although EGFRvIII fails to bind EGF, the tyrosine kinase in the intracellular portion is constitutively activated, so that the receptor undergoes tyrosine (Tyr) autophosphorylation. 13,16,19,20) We have previously shown that overexpression of EGFRvIII in NIH3T3 cells causes a highly transformed phenotype as a result of the ligand-independent activation of the receptor kinase.16) Furthermore, we have demonstrated the frequent expression of EGFRvIII in a variety of human tumors with or without EGFR amplification, suggesting that EGFRvIII confers a growth advantage upon tumor cells in vivo. [21][22][23][24][25][26] EGFRvIII has also been shown to be an extremely attractive target for anticancer therapy.15) In a rodent model, vaccination with a peptide corresponding to the alteration present in EGFRvIII could both prevent tumor formation and induce the regression of tumors expressing this receptor.27) More recently, it has been shown that systemic treatment of mice bearing tumors expressing EGFRvIII with monoclonal antibodi...

Background It is known that peritoneal mesothelial cells (PMCs) are denuded in patients undergoing long-term continuous ambulatory peritoneal dialysis (CAPD); the mechanism of damage is not well known. A high quantity of glucose loaded onto PMCs in these patients may generate toxic radicals during the mitochondrial metabolism, leading to mitochondrial DNA damage that accumulates due to the incomplete repair system of this DNA. Objective To study damage to the PMCs of long-term CAPD patients, and to examine whether glucose overload accelerates this damage in vitro. Design Descriptive clinical and in vitro study. Participants Stable CAPD patients and nonuremic patients undergoing elective abdominal surgery. Methods ( 1 ) Clinical Samples: 13 peritoneal tissue samples from CAPD patients and 5 omental tissue samples from patients with normal renal function were investigated. PMCs in dialysate effluent were collected from another 13 stable CAPD patients. ( 2 ) In Vitro Samples: Primary cultured PMCs were incubated for up to 144 hours in medium containing one of the following: 5.6 mmol/L glucose (control), 56 mmol/L glucose (G), 222 mmol/L glucose (high G), or 222 mmol/L mannitol (high M; osmolar control for high G). The tissues and cells of clinical and in vitro samples were stained for light and immunoelectron microscopy with anti–8-hydroxy-2'-deoxyguanosine (anti–8-OH-dG) antibody, a marker of oxidative DNA damage. In vitro cells were also studied using transmission electron microscopy. Cellular ATP content, mitochondrial membrane potential, and intracellular generation of reactive oxygen species (ROS) were analyzed by luciferase–luciferin system, or by flow cytometry using rhodamine 123 and 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). Results Biopsy specimens showed strong cytoplasmic staining with 8-OH-dG in patients on long-term CAPD, but only faint staining in patients with end-stage renal disease before the initiation of CAPD, and no staining in patients with normal renal function. Dialysate effluent showed strong granular staining with 8-OH-dG in most PMCs in all long-term CAPD patients, but only faint and focal staining in patients at the start and after 3 – 5 months of CAPD. In vitro experiments also showed strong granular staining by 8-OH-dG in most PMCs cultured in high G, weak staining in G and high M, and no staining in the control. Immunoelectron microscopy revealed the localization of 8-OH-dG to mitochondria. Transmission electron microscopy showed swelling of mitochondria, with decreased cristae, in PMCs cultured in high G. However, only partial expansion of mitochondria was seen in G and high M, and no changes were seen in the control. Cellular ATP content and mitochondrial membrane potential were reduced early, followed by an increase when cultured in high G. Intracellular ROS production was also increased in PMCs cultured in high G and high M. Conclusions These data suggest that high-glucose peritoneal dialysate may promote oxidative mitochondrial DNA damage in PMCs in CAPD patients.

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While mRNA vaccines against SARS-CoV-2 are exceedingly effective in preventing symptomatic infection, their immune response features remain to be clari ed. In the present prospective study, 225 healthy individuals in Japan, who received two BNT162b2 doses, were enrolled. Correlates of BNT162b2-elicited SARS-CoV-2-neutralizing activity (50% neutralization titer: NT 50 ; assessed using infectious virions) with various determinants were examined and the potency of serums against variants of concerns was determined. Signi cant rise in NT 50 s was seen in serums on day 28 post-1st dose. A moderate inverse correlation was seen between NT 50 s and ages, but no correlation seen between NT 50 s and adverse effects. NT 50 s and SARS-CoV-2-S1-binding-IgG levels on day 28 post-1st dose and pain scores following the 2nd shot were greater in women than in men. The average half-life of NT 50 s was ~ 68 days and the estimated average time length till the total disappearance of neutralizing activity was ~ 198 days. While serums from elite-responders (NT 50 s > 1,500-fold: the top 4% among the participants) potently to moderately blocked all variants of concerns examined, some serums with low NT 50 s failed to block the B.1.351-beta strain. Since BNT162b2-elicited immunity against SARS-CoV-2 is short, an additional vaccine or other protective measures are needed.