Impact of time from diagnosis to chemotherapy on prognosis in advanced pancreatic cancer.

BACKGROUND: Due to the aggressive nature and poor prognosis of advanced pancreatic cancer, prompt initiation of treatment is critical. We investigated the effect of the interval between cancer diagnosis and initiation of chemotherapy on survival in patients with advanced pancreatic cancer. METHODS: In this retrospective, single-centre study, consecutive patients with advanced pancreatic cancer between April 2013 and March 2022 were analyzed. Data were extracted from the electronic medical records of patients who received chemotherapy for metastatic, locally advanced or resectable pancreatic cancer or who received chemotherapy due to either being intolerant of or declining surgery. We compared overall survival between two groups: the early waiting time group (waiting time ≤30 days from diagnosis to chemotherapy initiation) and the elective waiting time group (waiting time ≥31 days). Prognostic factors, including biliary drainage, were considered. The impact of waiting time on survival was assessed by univariate and multivariate analyses with Cox proportional hazard models. A 1:1 propensity score matching approach was used to balance bias, accounting for significant poor prognosis factors, age and sex. RESULTS: The study involved 137 patients. Overall survival exhibited no statistically significant difference between the early and elective waiting time groups (207 and 261 days, P = 0.2518). Univariate and multivariate analyses identified poor performance status and metastasis presence as predictors of worse prognosis. This finding persisted post propensity score matching (275 and 222 days, P = 0.8223). CONCLUSIONS: Our study revealed that initiating chemotherapy ˃30 days later does not significantly affect treatment efficacy compared to within 30 days of diagnosis.

Impact of Initial Body Weight Loss on Prognosis in Advanced Pancreatic Cancer: Insights From a Single-Center Retrospective Study.

BACKGROUND: Pancreatic cancer (PC) has a poor prognosis, with body weight loss commonly observed at diagnosis. However, the impact on PC prognosis of weight loss at the time of diagnosis on PC prognosis is unknown. METHODS: This retrospective, single-center study enrolled consecutively patients diagnosed with metastatic or locally advanced PC or resectable PC who were intolerant of or refused surgery. Patients who had lost more than 5% of their body weight or more than 2% and had a body mass index (BMI) of less than 20 kg/m2 at diagnosis were classified as experiencing body weight loss. Patients were subclassified into 2 groups: patients with and without weight loss. The study evaluated patient-related and PC-related factors affecting prognosis. Cox proportional hazards models were used to assess factors affecting prognosis. The primary endpoint was overall survival. Additionally, 1:1 propensity score matching was performed to reduce bias. RESULTS: In total, 220 patients were included in the study. The median age of the patients was 74 years, and 49.1% were male. Weight loss at diagnosis was observed in 43.2% of patients. There were no significant differences in clinical factors, except for anthropometric parameters, between the groups. The median survival time did not differ between the weight loss and no weight loss groups (149 and 173 days, respectively, P = .669). After matching, no significant differences in survival times were observed between the 2 groups. CONCLUSIONS: This study found no association between weight loss at diagnosis and prognosis in patients with advanced PC treated with best supportive care or chemotherapy.

NRF3 activates mTORC1 arginine-dependently for cancer cell viability.

Cancer cells coordinate the mTORC1 signals and the related metabolic pathways to robustly and rapidly grow in response to nutrient conditions. Although a CNC-family transcription factor NRF3 promotes cancer development, the biological relevance between NRF3 function and mTORC1 signals in cancer cells remains unknown. Hence, we showed that NRF3 contributes to cancer cell viability through mTORC1 activation in response to amino acids, particularly arginine. NRF3 induced SLC38A9 and RagC expression for the arginine-dependent mTORC1 recruitment onto lysosomes, and it also enhanced RAB5-mediated bulk macropinocytosis and SLC7A1-mediated selective transport for arginine loading into lysosomes. Besides, the inhibition of the NRF3-mTORC1 axis impaired mitochondrial function, leading to cancer cell apoptosis. Consistently, the aberrant upregulation of the axis caused tumor growth and poor prognosis. In conclusion, this study sheds light on the unique function of NRF3 in arginine-dependent mTORC1 activation and the pathophysiological aspects of the NRF3-mTORC1 axis in cancer development.

The CNC-family transcription factor Nrf3 coordinates the melanogenesis cascade through macropinocytosis and autophagy regulation.

Melanin is a pigment produced from the amino acid L-tyrosine in melanosomes. The CNC-family transcription factor Nrf3 is expressed in the basal layer of the epidermis, where melanocytes reside, but its melanogenic function is unclear. Here, we show that Nrf3 regulates macropinocytosis and autophagy to coordinate melanogenesis cascade. In response to an exogenous inducer of melanin production, forskolin, Nrf3 upregulates the core melanogenic gene circuit, which includes Mitf, Tyr, Tyrp1, Pmel, and Oca2. Furthermore, Nrf3 induces the gene expression of Cln3, an autophagosome-related factor, for melanin precursor uptake by macropinocytosis. Ulk2 and Gabarapl2 are also identified as Nrf3-target autophagosome-related genes for melanosome formation. In parallel, Nrf3 prompts autolysosomal melanosome degradation for melanocyte survival. An endogenous melanogenic inducer αMSH also activates Nrf3-mediated melanin production, whereas it is suppressed by an HIV-1 protease inhibitor, nelfinavir. These findings indicate the significant role of Nrf3 in the melanogenesis and the anti-melanogenic potential of nelfinavir.

Exposure to a low concentration of methylmercury in neural differentiation downregulates NR4A1 expression with altered epigenetic modifications and inhibits neuronal spike activity in vitro.

Methylmercury (MeHg) is a well-known developmental neurotoxin. Our previous research showed that the inhibition of neurite extension by exposure to a low level of MeHg (1 nM) was attributed to the decrease of acetylation of histone H3 and the increase of DNA methylation. However, the target molecules responsible for the neurological dysfunctions caused by MeHg exposure have not been identified. This study focused on a nuclear receptor subfamily 4 group A member 1 (NR4A1), which is reported to be related to synaptic plasticity and neurite extension. LUHMES cells, which are derived from human fetal brain, were treated with 0.1 and 1 nM MeHg beginning at two days of differentiation and continued for 6 consecutive days. The present study showed that exposure to a 1 nM MeHg during neural differentiation inhibited neuronal spike activity and neurite extension. Furthermore, MeHg exposure increased DNA methylation, and altered histone modifications for transcriptional repression in the NR4A1 promoter region to decrease the levels of NR4A1 expression. In addition, MeHg exposure inhibited the mobilization of cAMP response element-binding protein (CREB) and CREB binding protein (CBP) in the NR4A1 promoter region. These results suggest that MeHg inhibits the recruitment of the CREB-CBP complex to the NR4A1 promoter region and impairs neuronal functions associated with NR4A1 repression via a decrease in acetylation of histone H3 lysine 14 levels. Conclusively, this study demonstrated that MeHg exposure during neuronal differentiation could induce neurological dysfunctions even at a low concentration in vitro. These dysfunctions could be associated with the transcriptional repression of NR4A1 by the dissociation of CREB and CBP from the NR4A1 promoter region due to the alterations of epigenetic modifications.

Nrf3 Functions Reversely as a Tumorigenic to an Antitumorigenic Transcription Factor in Obese Mice.

Tumor tissue includes cancer cells and their associated stromal cells, such as adipocytes, myocytes, and immune cells. Obesity modulates tumor microenvironment through the secretion of several inflammatory mediators by inducing adipogenesis and myogenesis. Previously, we indicated that tumor growth is promoted by a transcription factor nuclear factor erythroid 2-related factor 3 (NRF3) in human cancer cells. However, the impact of obesity on NRF3-mediated tumorigenesis remains unknown. Here we show that obesity reprograms the tumorigenic to the antitumorigenic function of Nrf3 using a diet-induced obese mouse model. Nrf3 knockdown decreased tumor growth in mice fed a normal diet (ND), whereas it reversely increased tumor growth in mice fed a high-fat diet (HFD). Then, the tumor tissues derived from Nrf3 knockdown or control cancer cells in ND- or HFD-fed mice were subjected to a DNA microarray-based analysis. Similar to the tumor formation results, the expressions of genes related to adipogenesis, myogenesis, and interferon-alpha response were reversed by obesity, implying an increase or recruitment (or both combined) of adipocytes, myocytes, and immune cells. Among these gene sets, we focused on adipocytes. We showed that Nrf3 knockdown reduced cancer cell growth in the preadipocyte culture medium, while the growth inhibitory effect of Nrf3 knockdown on cancer cells was abolished in the adipocyte culture medium. These results suggest the possibility that cancer-associated adipocytes secrete the potential reprogramming factor from the tumorigenic to the antitumorigenic function of Nrf3 in cancer cells.

Early Detection of Leukoplakic Oral Squamous Cell Carcinoma Using 4NQO-induced Rat Tongue Cancer Model: Study Utilizing Fluorescence Intensity and Histopathological Evaluation.

Early identification of leukoplakic oral squamous cell carcinoma (OSCC) is difficult. The purpose of this study was to determine whether it was possible to detect change from normal epithelium to leukoplakic OSCC using a fluorescence visualization (FV) device in a 4-nitroquinoline 1-oxide (4NQO) -induced rat tongue cancer model. If successful, this would facilitate early detection of OSCC. The rats (3 groups of 5) were administered 50 ppm 4NQO in their drinking water over a period of 10, 15, or 20 weeks. Five non-treated rats were used as a control group. Images of their tongues obtained by FV were analyzed for change in fluorescence intensity (FI) using image analysis software. Immunoreaction for anti-CK13, anti-CK17, and anti-E-cadherin antibodies was also histopathologically evaluated. Receiver operating characteristic (ROC) analysis was used to calculate the cut-off values, sensitivity, specificity, and area under the curve. The most marked change in FI was found between the control and 10-week groups, with an increase observed in its average value and range in the latter. These findings differed from those characteristic of leukoplakia. No significant difference was observed in the positive cell rate for immunoreaction for anti-CK13 or anti-CK17 antibodies between the control and 10-week groups. A significant decrease was observed in the positive pixel ratio of immunoreaction for anti-E-cadherin antibody in the 10-week group in comparison with in the control group (p <0.05). These results showed that disruption of intercellular adhesion could be observed at 10 weeks. In the ROC analysis, the FI cut-off value in the 10-week and control groups was 51.9, sensitivity 95.5%, and specificity 96.9%. This indicated that normal epithelium could be accurately distinguished from low-grade dysplasia with high probability. These results demonstrate that analysis of change in FI as measured by FV could facilitate early detection of leukoplakic OSCC.

Laminin ß2 variants associated with isolated nephropathy that impact matrix regulation.

Mutations in LAMB2, encoding laminin ß2, cause Pierson syndrome and occasionally milder nephropathy without extrarenal abnormalities. The most deleterious missense mutations that have been identified affect primarily the N-terminus of laminin ß2. On the other hand, those associated with isolated nephropathy are distributed across the entire molecule, and variants in the ß2 LEa-LF-LEb domains are exclusively found in cases with isolated nephropathy. Here we report the clinical features of mild isolated nephropathy associated with 3 LAMB2 variants in the LEa-LF-LEb domains (p.R469Q, p.G699R, and p.R1078C) and their biochemical characterization. Although Pierson syndrome missense mutations often inhibit laminin ß2 secretion, the 3 recombinant variants were secreted as efficiently as WT. However, the ß2 variants lost pH dependency for heparin binding, resulting in aberrant binding under physiologic conditions. This suggests that the binding of laminin ß2 to negatively charged molecules is involved in glomerular basement membrane (GBM) permselectivity. Moreover, the excessive binding of the ß2 variants to other laminins appears to lead to their increased deposition in the GBM. Laminin ß2 also serves as a potentially novel cell-adhesive ligand for integrin α4ß1. Our findings define biochemical functions of laminin ß2 variants influencing glomerular filtration that may underlie the pathogenesis of isolated nephropathy caused by LAMB2 abnormalities.

Human TRPA1 activation by terpenes derived from the essential oil of daidai, Citrus aurantium L. var. daidai Makino.

Daidai (bitter orange, Citrus aurantium) is characterized by its fresh citrus scent. In Japanese cuisine, its juice is an important ingredient. As tons of industrial waste is obtained while processing the daidai juice, additional utilization of this waste has great social value. In our study, we prepared the essential oil from the waste obtained during daidai juice processing and demonstrated that the oil activates human TRPA1 (hTRPA1). This oil contains 10 types of terpenes, all of which activated hTRPA1 with an EC50 value of 6-167 µM. To our knowledge, this study is the first to show a hTRPA1 activation by five terpenes: linalyl acetate, geranyl acetate, osthole, geranyl propionate, and neryl acetate. Because physiological benefits of TRPA1 agonists, such as enhancement of energy metabolism and promotion of skin barrier recovery, have been reported, the oil could be a promising ingredient for anti-obesity food products and cosmetics.

Morphology of GNAT3-immunoreactive chemosensory cells in the rat larynx.

The upper airways play important roles in respiratory defensive reflexes. Although solitary chemosensory cells and chemosensory cell clusters have been reported in the laryngeal mucosa of mammalian species, the distribution and cellular morphology of chemosensory cells remain unclear. In the present study, the distribution and morphology of solitary chemosensory cells and chemosensory cell clusters were examined by immunofluorescence for GNAT3 on whole-mount preparations of the rat laryngeal mucosa. Electrophysiological experiments were performed to analyze the respiratory reflexes evoked by bitter stimuli to the laryngeal cavity. In the whole area of the laryngeal mucosa, the numbers of GNAT3-immunoreactive solitary chemosensory cells and chemosensory clusters were 421.0 ± 20.3 and 62.7 ± 6.9, respectively. GNAT3-immunoreactive solitary chemosensory cells were mainly distributed in the mucosa overlying epiglottic and arytenoid cartilage, and chemosensory clusters were mainly distributed on the edge of the epiglottis and aryepiglottic fold. GNAT3-immunoreactive solitary chemosensory cells were slender with elongated processes or had a flask-like/columnar shape. The number of GNAT3-immunoreactive cells in chemosensory clusters was 6.1 ± 0.4, ranging between 2 and 14 cells. GNAT3-immunoreactive cells in the cluster were variform and the tips of apical processes gathered at one point at the surface of the epithelium. The tips of apical cytoplasmic processes in solitary chemosensory cells and cells in the cluster were immunoreactive for espin, and faced the laryngeal cavity. Physiological experiments showed that the application of 10 mm quinine hydrochloride to the laryngeal cavity decreased respiratory frequency. The present results revealed the chemosensory field of the larynx and the morphological characteristics of the laryngeal chemosensory system for respiratory depression.

Optimum second screening point for detection of coronary artery disease in hemodialysis patients without advanced coronary artery disease.

BACKGROUND: Screening for coronary artery disease (CAD) at the initiation of dialysis is a K/DOQI recommendation. However, it remains unclear when screening for CAD should be repeated in patients without significant disease at the time of starting dialysis. The objectives of this study were to determine: (1) the survival of hemodialysis (HD) patients without CAD at the initiation of dialysis, (2) the major predictors of CAD events, and (3) the best time to repeat screening for CAD after the initiation of HD. METHODS: In order to assess the occurrence of de novo major adverse cardiac events (MACE) in HD patients without CAD, we prospectively followed patients who were normal according to screening tests for CAD performed at the initiation of HD. To detect CAD, 177 of 305 new HD patients underwent coronary angiography and/or pharmacologic stress thallium-201 single photon emission computed tomography within 1 month after starting HD. Among these 177 patients, 100 did not have significant CAD and they were followed for a median of 24 months. RESULTS: Five MACE occurred during follow-up, but no events were observed within 1 year after starting HD. All 5 events occurred during the second year of HD (two events occurred immediately after the end of the first year). An increased level of C-reactive protein (CRP) was the only independent predictor of MACE (hazard ratio: 1.39; 95% CI: 1.03-1.78, p = 0.008) according to Cox regression analysis. The optimum cut-off value of CRP for predicting MACE was 3.5 mg/l. The MACE-free rate at 2 years (99 vs. 79%, p = 0.0008) was significantly higher in patients with a CRP level (3.5 mg/l than in those with a level <3.5 mg/l). CONCLUSION: One year after the initiation of HD could be the optimum time to repeat screening for CAD in patients without disease at the initiation of HD. If the serum CRP level is less than 3.5 mg/l, postponing repeat screening for CAD could be considered.

Genome-wide searching of single-nucleotide polymorphisms among eight distantly and closely related rice cultivars (Oryza sativa L.) and a wild accession (Oryza rufipogon Griff.).

We searched the genomes of eight rice cultivars (Oryza sativa L. ssp. japonica and ssp. indica) and a wild rice accession (Oryza rufipogon Griffith) for nucleotide polymorphisms, and identified 7805 polymorphic loci, including single-nucleotide polymorphisms (SNPs) and insertions/deletions (InDels), in predicted intergenic regions. Polymorphisms are useful as DNA markers for genetic analysis or positional cloning with segregating populations of crosses. Pairwise comparison between cultivars and a neighbor-joining tree calculated from SNPs agreed very well with relationships between rice strains predicted from pedigree data or calculated with other DNA markers such as p-SINE1 and simple sequence repeats (SSRs), suggesting that whole-genome SNP information can be used for analysis of evolutionary relationships. Using multiple SNPs to identify alleles, we drew a map to illustrate the alleles shared among the eight cultivars and the accession. The map revealed that most of the genome is mono- or di-allelic among japonica cultivars, whereas alleles well conserved among modern japonica paddy rice cultivars were often shared with indica cultivars or wild rice, suggesting that the genome structure of modern cultivars is composed of chromosomal segments from various genetic backgrounds. Use of allele-sharing analysis and association analysis were also tested and are discussed.

Positional cloning of rice semidwarfing gene, sd-1: rice "green revolution gene" encodes a mutant enzyme involved in gibberellin synthesis.

A rice semidwarfing gene, sd-1, known as the "green revolution gene," was isolated by positional cloning and revealed to encode gibberellin 20-oxidase, the key enzyme in the gibberellin biosynthesis pathway. Analysis of 3477 segregants using several PCR-based marker technologies, including cleaved amplified polymorphic sequence, derived-CAPS, and single nucleotide polymorphisms revealed 1 ORF in a 6-kb candidate interval. Normal-type rice cultivars have an identical sequence in this region, consisting of 3 exons (558, 318, and 291 bp) and 2 introns (105 and 1471 bp). Dee-Geo-Woo-Gen-type sd-1 mutants have a 383-bp deletion from the genome (278-bp deletion from the expressed sequence), from the middle of exon 1 to upstream of exon 2, including a 105-bp intron, resulting in a frame-shift that produces a termination codon after the deletion site. The radiation-induced sd-1 mutant Calrose 76 has a 1-bp substitution in exon 2, causing an amino acid substitution (Leu [CTC] to Phe [TTC]). Expression analysis suggests the existence of at least one more locus of gibberellin 20-oxidase which may prevent severe dwarfism from developing in sd-1 mutants.

Lateral root formation is blocked by a gain-of-function mutation in the SOLITARY-ROOT/IAA14 gene of Arabidopsis.

Lateral root development is a post-embryonic organogenesis event that gives rise to most of the underground parts of higher plants. Auxin promotes lateral root formation, but the molecular mechanisms involved are still unknown. We have isolated a novel Arabidopsis mutant, solitary-root (slr), which has reduced sensitivity to auxin. This dominant slr-1 mutant completely lacks lateral roots, and this phenotype cannot be rescued by the application of exogenous auxin. Analysis with cell-cycle and cell-differentiation markers revealed that the slr-1 mutation blocks cell divisions of pericycle cells in lateral root initiation. The slr-1 mutant is also defective in root hair formation and in the gravitropic responses of its roots and hypocotyls. Map-based positional cloning and isolation of an intragenic suppressor mutant revealed that SLR encodes IAA14, a member of the Aux/IAA protein family. Green fluorescent protein-tagged mutant IAA14 protein was localized in the nucleus, and the gain-of-function slr-1/iaa14 mutation decreased auxin-inducible BA-GUS gene expression in the root, suggesting that SLR/IAA14 acts as a transcriptional repressor. These observations indicate that SLR/IAA14 is a key regulator in auxin-regulated growth and development, particularly in lateral root formation.