Effect of Luseogliflozin, a Sodium-Glucose Cotransporter 2 Inhibitor, and Dipeptidyl-Peptidase 4 Inhibitors on the Quality-of-Life and Treatment Satisfaction of Patients With Type 2 Diabetes Mellitus: A Subanalysis of a Multicenter, Open-Label, Randomized-Controlled Trial (J-SELECT Study)

INTRODUCTION

The effects of dipeptidyl peptidase-4 inhibitors (DPP-4is) and sodium-glucose cotransporter 2 inhibitors (SGLT2is) on quality of life (QOL) and treatment satisfaction have not been directly compared. This sub-analysis of a randomized-controlled trial with an SGLT2i, luseogliflozin, and DPP-4is compared their effects on QOL and treatment satisfaction of patients.

METHODS

This study recruited 623 patients with type 2 diabetes mellitus who were drug-naïve or treated with antidiabetic agents other than SGLT2is and DPP-4is. The patients were randomized into luseogliflozin or DPP-4i group and followed for 52 weeks. This sub-analysis assessed QOL and treatment satisfaction using Oral Hypoglycemic Agent Questionnaire (OHA-Q) version 2 in the drug-naïve subgroup who were drug-naïve at baseline and with monotherapy with luseogliflozin or DPP-4i throughout the observation period (256 patients) at 24 and 52 weeks and in the add-on subgroup who were treated with OHAs other than SGLT2is and DPP-4is (204 patients) at baseline, 24 and 52 weeks.

RESULTS

In the drug-naïve subgroup, total (50.8 ± 8.2 in luseogliflozin group and 53.1 ± 10.0 in DPP-4i group, p = 0.048) and somatic symptom scores (22.4 ± 5.0 in luseogliflozin group and 24.4 ± 5.8 in DPP-4i group, p = 0.005) at 52 weeks (but not at 24 weeks) were significantly higher in DPP-4i group than in luseogliflozin group. In add-on subgroup, changes in total (3.3 ± 7.8 in luseogliflozin group and 0.9 ± 7.6 in DPP-4i group, p = 0.030) and treatment convenience (1.2 ± 3.9 in luseogliflozin group and - 0.6 ± 4.2 in DPP-4i group, p = 0.002) from baseline to 24 weeks (but not at 52 weeks) were significantly greater in luseogliflozin group than in DPP-4i group. The QOL related to safety or glycemic control was comparable between the groups.

CONCLUSIONS

Physicians should pay attention to side effects of SGLT2is to maintain the patients' QOL when SGLT2is are initiated or added-on. Add-on of luseogliflozin increased patients' QOL more than DPP-4is. Considering patients' QOL and treatment satisfaction is important for selecting SGLT2is or DPP-4is.

TRIAL REGISTRATION

UMIN000030128 and jRCTs031180241.

Redoxisome Update: TRX and TXNIP/TBP2-Dependent Regulation of NLRP-1/NLRP-3 Inflammasome

Recent studies have provided evidence for the direct binding of thioredoxin-1 (TRX1) to a component of inflammasome complex NLR family pyrin domain containing 1 (NLRP-1). This interaction suggests a potential role for TRX1 in the regulation of the NLRP-1 inflammasome. Furthermore, the NLRP-3 inflammasome is known to bind TRX1 and its inhibitor, TRX-binding protein-2/TRX-interacting protein/vitamin D3 upregulated protein-1 (TBP2/TXNIP/VDUP-1). This binding forms a redox-sensitive complex, termed the "Redoxisome," as described previously. However, the specific functions of NLRP-1 within the redoxisome complex remain undefined. Antioxid. Redox Signal. 40, 595-597.

Lysyl oxidase-like 4 promotes the invasiveness of triple-negative breast cancer cells by orchestrating the invasive machinery formed by annexin A2 and S100A11 on the cell surface

Background

Our earlier research revealed that the secreted lysyl oxidase-like 4 (LOXL4) that is highly elevated in triple-negative breast cancer (TNBC) acts as a catalyst to lock annexin A2 on the cell membrane surface, which accelerates invasive outgrowth of the cancer through the binding of integrin-β1 on the cell surface. However, whether this machinery is subject to the LOXL4-mediated intrusive regulation remains uncertain.

Methods

Cell invasion was assessed using a transwell-based assay, protein-protein interactions by an immunoprecipitation-Western blotting technique and immunocytochemistry, and plasmin activity in the cell membrane by gelatin zymography.

Results

We revealed that cell surface annexin A2 acts as a receptor of plasminogen via interaction with S100A10, a key cell surface annexin A2-binding factor, and S100A11. We found that the cell surface annexin A2/S100A11 complex leads to mature active plasmin from bound plasminogen, which actively stimulates gelatin digestion, followed by increased invasion.

Conclusion

We have refined our understanding of the role of LOXL4 in TNBC cell invasion: namely, LOXL4 mediates the upregulation of annexin A2 at the cell surface, the upregulated annexin 2 binds S100A11 and S100A10, and the resulting annexin A2/S100A11 complex acts as a receptor of plasminogen, readily converting it into active-form plasmin and thereby enhancing invasion.

DKK3 expression is correlated with poorer prognosis in head and neck squamous cell carcinoma: A bioinformatics study based on the TCGA database

OBJECTIVE

We previously reported that dickkopf WNT signaling pathway inhibitor 3 (DKK3) expression is correlated with poorer prognosis in head and neck squamous cell carcinoma (HNSCC). Here we investigated DKK3 expression by using The Cancer Genome Atlas (TCGA) public database and bioinformatic analyses.

METHODS

We used the RNA sequence data and divided the tumor samples into "DKK3-high" and "DKK3-low" groups according to median DKK3 expression. The correlations between DKK3 expression and the clinical data were investigated. Differentially expressed genes (DEGs) were detected using DESEq2 and analyzed by ShinyGO 0.77. A gene set enrichment analysis (GSEA) was also performed using GSEA software. The DEGs were also analyzed with TargetMine to establish the protein-protein interaction (PPI) network.

RESULTS

DKK3 expression was significantly increased in cancer samples, and a high DKK3 expression was significantly associated with shorter overall survival. We identified 854 DEGs, including 284 up-regulated and 570 down-regulated. Functional enrichment analyses revealed several Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with extracellular matrix remodeling. The PPI network identified COL8A1, AGTR1, FN1, P4HA3, PDGFRB, and CEP126 as the key genes.

CONCLUSIONS

These results suggested the cancer-promoting ability of DKK3, the expression of which is a promising prognostic marker and therapeutic target for HNSCC.

DKK3/CKAP4 axis is associated with advanced stage and poorer prognosis in oral cancer

OBJECTIVE

We previously reported that dickkopf WNT signaling inhibitor 3 (DKK3) would modulate malignant potential of oral squamous cell carcinoma (OSCC) via activating Akt. Recently, cytoskeleton associated protein 4 (CKAP4) functions as receptor of DKK3, which activates Akt in esophageal squamous cell carcinoma, but its expression and function in OSCC were unclear.

METHODS

We studied DKK3 and CKAP4 protein expression in OSCC tissue and investigated the correlation between protein expression and clinical data. We also investigated whether antibodies (Ab) for DKK3 or CKAP4 could suppress malignant potential of the cancer cells.

RESULTS

DKK3/CKAP4 protein expression was observed in majority of OSCC cases and was associated with significantly higher T-stage and TNM stage. Multivariate analysis revealed that DKK3 and CKAP4 were independent prognostic biomarkers for overall survival (OS) and disease-free survival (DFS), respectively. Survival analyses revealed that DKK3-positive cases and CKAP4-positive cases showed significantly shorter OS and DFS, respectively, and that DKK3/CKAP4 double-negative cases showed significantly favorable prognosis. Both anti-DKK3Ab and anti-CKAP4Ab could suppress cancer cell proliferation, migration, and invasion.

CONCLUSION

DKK3/CKAP4 axis is thought to be important in OSCC, and it would be a promising therapeutic target.

Overall Efficacy and Safety of Sodium-Glucose Cotransporter 2 Inhibitor Luseogliflozin Versus Dipeptidyl-Peptidase 4 Inhibitors: Multicenter, Open-Label, Randomized-Controlled Trial (J-SELECT study)

INTRODUCTION

Evidence of a direct comparison between dipeptidyl-peptidase 4 inhibitors (DPP-4is) and sodium-glucose cotransporter 2 inhibitors (SGLT2is) remains lacking, and no clear treatment strategy or rationale has been established using these drugs. This study aimed to compare the overall efficacy and safety of DPP-4is and the SGLT2i luseogliflozin in patients with type 2 diabetes mellitus (T2DM).

METHODS

Patients with T2DM who had not used antidiabetic agents or who had used antidiabetic agents other than SGLT2is and DPP-4is were enrolled in the study after written informed consent had been obtained. The enrolled patients were subsequently randomly assigned to either the luseogliflozin or DPP-4i group and followed up for 52 weeks. The primary (composite) endpoint was the proportion of patients who showed improvement in ≥ 3 endpoints among the following five endpoints from baseline to week 52: glycated hemoglobin (HbA1c), weight, estimated glomerular filtration rate (eGFR), systolic blood pressure, and pulse rate.

RESULTS

A total of 623 patients were enrolled in the study and subsequently randomized to either the luseogliflozin or DPP-4i groups. The proportion of patients who showed improvement in ≥ 3 endpoints at week 52 was significantly higher in the luseogliflozin group (58.9%) than in the DPP-4i group (35.0%) (p < 0.001). When stratified by body mass index (BMI) (< 25 or ≥ 25 kg/m²) or age (< 65 or ≥ 65 years), regardless of BMI or age, the proportion of patients who achieved the composite endpoint was significantly higher in the luseogliflozin group than in the DPP-4i group. Hepatic function and high-density lipoprotein-cholesterol were also significantly improved in the luseogliflozin group compared with the DPP-4i group. The frequency of non-serious/serious adverse events did not differ between the groups.

CONCLUSION

This study showed the overall efficacy of luseogliflozin compared with DPP-4is over the mid/long term, regardless of BMI or age. The results suggest the importance of assessing multiple aspects regarding the effects of diabetes management.

TRIAL REGISTRATION NUMBER

jRCTs031180241.

Abstract P2-05-02: Potential Empowerment and risk of Genetic Counseling with Genetic Breast cancer risk assessment in Personalized Health Care: Prospective Cohort Study using Genetic Counseling Outcome Scale (GCOS-24)

[Introduction] Personalized health care is recommended for the prevention and early detection of breast cancer. Advances in technology have made it possible to estimate genetic risk, PGV (pathogenic/likely-pathogenic germline variant) or PRS (polygenic risk score), in practice. However, linkage after risk assessment to personalized health care is still developing. One of the issues is how to tell the result especially in case of newly diagnosed PGV after Genetic Panel Testing or PRS. In this study, we evaluated genetic counseling (GC) using an established patient-reported outcome measure for clinical genetics services scale (Genetic Counseling Outcome Scale24 (GCOS24)) at genetic counseling for disclosure the results of the previous study, and examined the association with management after GC. [Method] We performed targeted sequencing for 11 breast cancer-related genes using peripheral blood DNA from 1995 female breast cancer patients. Of 1995 cases, 101 patients were PGV carriers, who were candidates of this study. Participants were referred to the Clinical Genetics unit, Kyoto University Hospital from 10 institutions (January 2018-March 2022). GCOS24 and relating questionaries were asked before and after GC. GCOS24 is a scale consisting of 24 items that assess five factors: decision control, cognitive control, behavioral control, emotional regulation, and hope. (In light of the current status of hereditary breast cancer care in Japan, 23 items were used.) Each item is rated on a scale of 1-7 points, for a total score of 23-161. In addition, we reviewed medical records to evaluate the post-GC management. [Results] Of the 101 cases, 38 cases were enrolled. The reasons of 63 not-enrolled cases were: 30 cases without follow-up (deaths or transfer to another hospital), 11 cases already diagnosed in clinical practice, 18 cases that did not wish to know their results, and 4 cases whose hospital were developing for hereditary breast cancer care. Median age at the time of genetic GC was 55 (min-max 30-83) years. Details of PGV cases were: BRCA2 23 cases, BRCA1 2, PALB2 4, PTEN 3, TP53 3, ATM 1, CHEK2 1 and NF1 1. GCOS24 after GC were improved than before GC. (Average 99 (min-max 17-124) vs 114 (91-138), Mean difference 23.9, 95% Confidence intervals (CI) 29.6 to 18.3). Thirty patients (79%) had higher increase in scores than 10.3, which was the previously reported Minimum Clinically Important Difference (MCID) of this scale. In all items except 4 items (#6,11,13,21), GCOS24 after GC were significantly improved than before GC. In post-GC management, 8 patients received or planned RRSO (risk reducing salpingo-oophorectomy) among 25 BRCA1/2 cases. There was a case with dysplastic cells detected in the resected ovary. After GC, average of GCOS24 in RRSO cases was 120 (95% CI 110 to 129), while average of GCOS24 of other BRCA1/2 cases was 110 (95% CI 104 to 116). On the other hand, two patients stopped visiting to the hospital because of fear after GC. Average of GCOS24 of 15 junior-high/high school graduate cases were 111 (95% CI 105 to 117), while average of GCOS24 of 23 college graduate cases were 117 (95% CI 111 to 122). [Discussion] In patients diagnosed with hereditary breast cancer by genetic panel testing, GC worked well except for 4 items. These 4 items (#6,11,13,21) were related to emotion. This study revealed there was also a risk to reject surveillance due to fear, suggesting that it is necessary to provide psychological support in some cases. Although the limitation of this study is the small number of cases, GCOS24 were high in RRSO cases, suggesting that GC played an important role when proceeding with intervention. We believe that the findings are helpful for the future implementation of genetic panel testing or PRS testing in healthy subjects for personalized health care.

Citation Format: Nobuko Kawaguchi-Sakita, Noriko Senda, Yukiko Inagaki-Kawata, Hiromi Murakami, Sayaka Honda, Takahiro Yamada, Yuki Kataoka, Shoko Takahara, Shigeru Tsuyuki, Kazuhiko Yamagami, Yoshio Moriguchi, Masae Torii, Tatsushi Kato, Hirofumi Suwa, Wakako Tsuji, Eiji Suzuki, Akira Yamauchi, Ryuji Okamura, Shinji Kosugi, Masakazu Toi. Potential Empowerment and risk of Genetic Counseling with Genetic Breast cancer risk assessment in Personalized Health Care: Prospective Cohort Study using Genetic Counseling Outcome Scale (GCOS-24) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-05-02.

Characterization of missense mutations in the NADPH oxidase partner p22phox in the A22° subtype of chronic granulomatous disease

Defective superoxide production by NADPH oxidase 2 (Nox2) in phagocyte cells results in the development of chronic granulomatous disease (CGD), a hereditary disease characterized by recurrent and life-threatening infections. The partner protein p22^phox is a membrane-spanning protein which forms a stable heterodimer with Nox2 in the endoplasmic reticulum. This interaction ensures the stability of each protein and their accurate trafficking to the cell membrane. The present paper describes the characterization of p22^phox missense mutations that were identified in a patient with CGD who presented with undetectable levels of p22^phox . Using a reconstitution system, it was found that p22^phox expression decreased when R90Q, A117E, S118R, A124S, A124V, A125T, or E129K mutations were introduced, suggesting that these mutations destabilize the protein. In contrast, introducing an L105R mutation did not affect protein expression, but did inhibit p22^phox binding to Nox2. Thus, the missense mutations discussed here contribute to the development of CGD by either disrupting protein stability or by impairing the interaction between p22^phox and Nox2.

LOXL1 and LOXL4 are novel target genes of the Zn2+-bound form of ZEB1 and play a crucial role in the acceleration of invasive events in triple-negative breast cancer cells

Background

EMT has been proposed to be a crucial early event in cancer metastasis. EMT is rigidly regulated by the action of several EMT-core transcription factors, particularly ZEB1. We previously revealed an unusual role of ZEB1 in the S100A8/A9-mediated metastasis in breast cancer cells that expressed ZEB1 at a significant level and showed that the ZEB1 was activated on the MCAM-downstream pathway upon S100A8/A9 binding. ZEB1 is well known to require Zn²⁺ for its activation based on the presence of several Zn-finger motifs in the transcription factor. However, how Zn²⁺-binding works on the pleiotropic role of ZEB1 through cancer progression has not been fully elucidated.

Methods

We established the engineered cells, MDA-MB-231 MutZEB1 (MDA-MutZEB1), that stably express MutZEB1 (ΔZn). The cells were then evaluated in vitro for their invasion activities. Finally, an RNA-Seq analysis was performed to compare the gene alteration profiles of the established cells comprehensively.

Results

MDA-MutZEB1 showed a significant loss of the EMT, ultimately stalling the invasion. Inclusive analysis of the transcription changes after the expression of MutZEB1 (ΔZn) in MDA-MB-231 cells revealed the significant downregulation of LOX family genes, which are known to play a critical role in cancer metastasis. We found that LOXL1 and LOXL4 remarkably enhanced cancer invasiveness among the LOX family genes with altered expression.

Conclusions

These findings indicate that ZEB1 potentiates Zn²⁺-mediated transcription of plural EMT-relevant factors, including LOXL1 and LOXL4, whose upregulation plays a critical role in the invasive dissemination of breast cancer cells.

Lysyl oxidase-like 4 exerts an atypical role in breast cancer progression that is dependent on the enzymatic activity that targets the cell-surface annexin A2

Background

LOX family members are reported to play pivotal roles in cancer. Unlike their enzymatic activities in collagen cross-linking, their precise cancer functions are unclear. We revealed that LOXL4 is highly upregulated in breast cancer cells, and we thus sought to define an unidentified role of LOXL4 in breast cancer.

Methods

We established the MDA-MB-231 sublines MDA-MB-231-LOXL4 mutCA and -LOXL4 KO, which stably overexpress mutant LOXL4 that loses its catalytic activity and genetically ablates the intrinsic LOXL4 gene, respectively. In vitro and in vivo evaluations of these cells' activities of cancer outgrowth were conducted by cell-based assays in cultures and an orthotopic xenograft model, respectively. The new target (s) of LOXL4 were explored by the MS/MS analytic approach.

Results

Our in vitro results revealed that both the overexpression of mutCA and the KO of LOXL4 in cells resulted in a marked reduction of cell growth and invasion. Interestingly, the lowered cellular activities observed in the engineered cells were also reflected in the mouse model. We identified a novel binding partner of LOXL4, i.e., annexin A2. LOXL4 catalyzes cell surface annexin A2 to achieve a cross-linked multimerization of annexin A2, which in turn prevents the internalization of integrin β-1, resulting in the locking of integrin β-1 on the cell surface. These events enhance the promotion of cancer cell outgrowth.

Conclusions

LOXL4 has a new role in breast cancer progression that occurs via an interaction with annexin A2 and integrin β-1 on the cell surface.

Identification of anti-SARS-CoV-2 agents based on flavor/fragrance compositions that inhibit the interaction between the virus receptor binding domain and human angiotensin converting enzyme 2

Coronavirus disease 2019 (COVID-19) pandemic poses a threat to human beings and numerous cases of infection as well as millions of victims have been reported. The binding of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor binding domain (RBD) to human angiotensin converting enzyme 2 (hACE2) is known to promote the engulfment of the virus by host cells. Employment of flavor/fragrance compositions to prevent SARS-CoV-2 infection by inhibiting the binding of viral RBD (vRBD) to hACE2 might serve as a favorable, simple, and easy method for inexpensively preventing COVID-19, as flavor/fragrance compositions are known to directly interact with the mucosa in the respiratory and digestive systems and have a long history of use and safety assessment. Herein we report the results of screening of flavor/fragrance compositions that inhibit the binding of vRBD to hACE2. We found that the inhibitory effect was observed with not only the conventional vRBD, but also variant vRBDs, such as L452R, E484K, and N501Y single-residue variants, and the K417N+E484K+N501Y triple-residue variant. Most of the examined flavor/fragrance compositions are not known to have anti-viral effects. Cinnamyl alcohol and Helional inhibited the binding of vRBD to VeroE6 cells, a monkey kidney cell line expressing ACE2. We termed the composition with inhibitory effect on vRBD-hACE2 binding as "the molecularly targeted flavor/fragrance compositions". COVID-19 development could be prevented by using these compositions with reasonable administration methods such as inhalation, oral administration, and epidermal application.

Establishment of anti-DKK3 peptide for the cancer control in head and neck squamous cell carcinoma (HNSCC)

Background

Head and neck squamous cell carcinoma (HNSCC) is the most common malignant tumor of the head and neck. We identified cancer-specific genes in HNSCC and focused on DKK3 expression. DKK3 gene codes two isoforms of proteins (secreted and non-secreted) with two distinct cysteine rich domains (CRDs). It is reported that DKK3 functions as a negative regulator of oncogenic Wnt signaling and, is therefore, considered to be a tumor suppressor gene. However, our series of studies have demonstrated that DKK3 expression is specifically high in HNSCC tissues and cells, and that DKK3 might determine the malignant potentials of HNSCC cells via the activation of Akt. Further analyses strongly suggested that both secreted DKK3 and non-secreted DKK3 could activate Akt signaling in discrete ways, and consequently exert tumor promoting effects. We hypothesized that DKK3 might be a specific druggable target, and it is necessary to establish a DKK3 inhibitor that can inhibit both secreted and non-secreted isoforms of DKK3.

Methods

Using inverse polymerase chain reaction, we generated mutant expression plasmids that express DKK3 without CRD1, CRD2, or both CRD1 and CRD2 (DKK3ΔC1, DKK3ΔC2, and DKK3ΔC1ΔC2, respectively). These plasmids were then transfected into HNSCC-derived cells to determine the domain responsible for DKK3-mediated Akt activation. We designed antisense peptides using the MIMETEC program, targeting DKK3-specific amino acid sequences within CRD1 and CRD2. The structural models for peptides and DKK3 were generated using Raptor X, and then a docking simulation was performed using CluPro2. Afterward, the best set of the peptides was applied into HNSCC-derived cells, and the effects on Akt phosphorylation, cellular proliferation, invasion, and migration were assessed. We also investigated the therapeutic effects of the peptides in the xenograft models.

Results

Transfection of mutant expression plasmids and subsequent functional analyses revealed that it is necessary to delete both CRD1 and CRD2 to inhibit Akt activation and inhibition of proliferation, migration, and invasion. The inhibitory peptides for CRD1 and CRD2 of DKK3 significantly reduced the phosphorylation of Akt, and consequently suppressed cellular proliferation, migration, invasion and in vivo tumor growth at very low doses.

Conclusions

This inhibitory peptide represents a promising new therapeutic strategy for HNSCC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02783-9.

QTL analysis for sodium removal ability in rice leaf sheaths under salinity using an IR-44595/318 F2 population

Over-accumulation of salt in rice plants is an effect of salt stress which decreases growth and grain yield. Salt removal ability in leaf sheaths is a tolerance mechanism to decrease salt entry and accumulation in leaf blades and maintain photosynthesis under salinity. In this study, a QTL analysis of removal ability of sodium ions (Na⁺) in leaf sheaths and Na⁺ accumulation-related traits, was conducted using F₂ population between two rice varieties, IR-44595 with superior Na⁺ removal ability, and 318 with contrasting Na⁺ removal ability in leaf sheaths under salinity. Suggestive QTLs for Na⁺ removal ability in leaf sheaths were found on chromosomes 4 and 11. The suggestive QTL on chromosome 11 overlapped with other significant QTLs for Na⁺ concentration in shoots, leaf blades and leaf sheaths, and Na⁺/K⁺ ratio in leaf blades. Correlation analysis indicated that Na⁺ removal ability in leaf sheaths is important in reducing Na⁺ accumulation in leaf blades. The varietal difference of Na⁺ removal ability in leaf sheaths at the whole plant level was greater at lower NaCl concentrations and became smaller as the treatment NaCl concentration increased. Although the Na⁺ removal ability in leaf sheath was comparable between IR-44595 and 318 under high salinity at the whole plant level, the younger leaves of IR-44595 still showed a higher Na⁺ sheath-blade ratio than 318, which implied the Na⁺ removal ability functions in the younger leaves in IR-44595 to reduce Na⁺ entry in young leaf blades even under high salinity.

Regulation of Derlin-1-mediated degradation of NADPH oxidase partner p22phox by thiol modification

The transmembrane protein p22^phox heterodimerizes with NADPH oxidase (Nox) 1–4 and is essential for the reactive oxygen species-producing capacity of oxidases. Missense mutations in the p22^phox gene prevent the formation of phagocytic Nox2-based oxidase, which contributes to host defense. This results in chronic granulomatous disease (CGD), a severe primary immunodeficiency syndrome. In this study, we characterized missense mutations in p22^phox (L51Q, L52P, E53V, and P55R) in the A22° type (wherein the p22^phox protein is undetectable) of CGD. We demonstrated that these substitutions enhanced the degradation of the p22^phox protein in the endoplasmic reticulum (ER) and the binding of p22^phox to Derlin-1, a key component of ER-associated degradation (ERAD). Therefore, the L⁵¹-L⁵²-E⁵³-P⁵⁵ sequence is responsible for protein stability in the ER. We observed that the oxidation of the thiol group of Cys-50, which is adjacent to the L⁵¹-L⁵²-E⁵³-P⁵⁵ sequence, suppressed p22^phox degradation. However, the suppression effect was markedly attenuated by the serine substitution of Cys-50. Blocking the free thiol of Cys-50 by alkylation or C50S substitution promoted the association of p22^phox with Derlin-1. Derlin-1 depletion partially suppressed the degradation of p22^phox mutant proteins. Furthermore, heterodimerization with p22^phox (C50S) induced rapid degradation of not only Nox2 but also nonphagocytic Nox4 protein, which is responsible for redox signaling. Thus, the redox-sensitive Cys-50 appears to determine whether p22^phox becomes a target for degradation by the ERAD system through its interaction with Derlin-1.

•

Missense mutations in exon 3 of p22^phox enhance the binding of p22^phox to Derlin-1.

•

Oxidation of the thiol group of p22^phox Cys50 suppresses p22^phox degradation.

•

Serine substitution of Cys-50 increases the affinity of p22^phox for Derlin-1.

•

Stability of the p22^phox protein is regulated by redox-sensitive Cys-50.

Histidine-Rich Glycoprotein Suppresses the S100A8/A9-Mediated Organotropic Metastasis of Melanoma Cells

The dissection of the complex multistep process of metastasis exposes vulnerabilities that could be exploited to prevent metastasis. To search for possible factors that favor metastatic outgrowth, we have been focusing on secretory S100A8/A9. A heterodimer complex of the S100A8 and S100A9 proteins, S100A8/A9 functions as a strong chemoattractant, growth factor, and immune suppressor, both promoting the cancer milieu at the cancer-onset site and cultivating remote, premetastatic cancer sites. We previously reported that melanoma cells show lung-tropic metastasis owing to the abundant expression of S100A8/A9 in the lung. In the present study, we addressed the question of why melanoma cells are not metastasized into the brain at significant levels in mice despite the marked induction of S100A8/A9 in the brain. We discovered the presence of plasma histidine-rich glycoprotein (HRG), a brain-metastasis suppression factor against S100A8/A9. Using S100A8/A9 as an affinity ligand, we searched for and purified the binding plasma proteins of S100A8/A9 and identified HRG as the major protein on mass spectrometric analysis. HRG prevents the binding of S100A8/A9 to the B16-BL6 melanoma cell surface via the formation of the S100A8/A9 complex. HRG also inhibited the S100A8/A9-induced migration and invasion of A375 melanoma cells. When we knocked down HRG in mice bearing skin melanoma, metastasis to both the brain and lungs was significantly enhanced. The clinical examination of plasma S100A8/A9 and HRG levels showed that lung cancer patients with brain metastasis had higher S100A8/A9 and lower HRG levels than nonmetastatic patients. These results suggest that the plasma protein HRG strongly protects the brain and lungs from the threat of melanoma metastasis.

QTL mapping under salt stress in rice using a Kalarata-Azucena population

Salt stress is a major constraint across large rice production areas in Asia, because of the high sensitivity of modern rice varieties. To identify quantitative trait loci (QTL) associated with salt tolerance in rice, we developed an F₂ population from a cross between the salt-tolerant landrace, Kalarata, and the salt-sensitive parent, Azucena. F3 families from this population were screened and scored for salt tolerance using IRRI's Standard evaluation system (SES). Growth, biomass, Na⁺ and K⁺ concentrations in leaf tissues, and chlorophyll concentration were determined. A genetic linkage map was constructed with 151 SSRs and InDel markers, which cover 1463 cM with an average distance of 9.69 cM between loci. A total of 13 QTL were identified using Composite Interval Mapping for 16 traits. Several novel QTL were identified in this study, the largest is for root sodium concentration (LOD = 11.0, R² = 25.0) on chromosome 3, which also co-localize with a QTL for SES. Several QTL on the short arm of chromosome 1 coincide with the Saltol locus identified before. The novel QTL identified in this study constitute future targets for molecular breeding, to combine them with other QTL identified before, for higher tolerance and stable performance of rice varieties in salt affected soils.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10681-022-03026-8.

The downregulation of NADPH oxidase Nox4 during hypoxia in hemangioendothelioma cells: a possible role of p22phox on Nox4 protein stability

NADPH oxidase (Nox) 4 produces H₂O₂ by forming a heterodimer with p22^phox and is involved in hemangioendothelioma development through monocyte chemoattractant protein-1 (MCP-1) upregulation. Here, we show that Nox4 protein levels were maintained by p22^phox in hemangioendothelioma cells and Nox4 protein stability was dependent on p22^phox coexpression. Conversely, the degradation of Nox4 monomer was enhanced by p22^phox knockdown. Under hypoxic conditions in hemangioendothelioma cells, p22^phox was downregulated at the mRNA and protein levels. Downregulation of p22^phox protein resulted in the enhanced degradation of Nox4 protein in hypoxia-treated hemangioendothelioma cells. In contrast, Nox2, a Nox isoform, was not altered at the protein level under hypoxic conditions. Nox2 exhibited a higher affinity for p22^phox compared with Nox4, suggesting that when coexpressed with Nox4 in the same cells, Nox2 acts as a competitor. Nox2 knockdown restored Nox4 protein levels partially reduced by hypoxic treatment. Thus, Nox4 protein levels were attenuated in hypoxia-treated cells resulting from p22^phox depletion. MCP-1 secretion was decreased concurrently with hypoxia-induced Nox4 downregulation compared with that under normoxia.

Coculture in vitro with endothelial cells induces cytarabine resistance of acute myeloid leukemia cells in a VEGF-A/VEGFR-2 signaling-independent manner

An interaction between acute myeloid leukemia (AML) cells and endothelial cells in the bone marrow seems to play a critical role in chemosensitivity on leukemia treatment. The endothelial niche reportedly enhances the paracrine action of the soluble secretory proteins responsible for chemoresistance in a vascular endothelial growth factor A (VEGF-A)/VEGF receptor 2 (VEGFR-2) signaling pathway-dependent manner. To further investigate the contribution of VEGF-A/VEGFR-2 signaling to the chemoresistance of AML cells, a biochemical assay system in which the AML cells were cocultured with human endothelial EA.hy926 cells in a monolayer was developed. By coculture with EA.hy926 cells, this study revealed that the AML cells resisted apoptosis induced by the anticancer drug cytarabine. SU4312, a VEGFR-2 inhibitor, attenuated VEGFR-2 phosphorylation and VEGF-A/VEGFR-2 signaling-dependent endothelial cell migration; thus, this inhibitor was observed to block VEGF-A/VEGFR-2 signaling. Interestingly, this inhibitor did not reverse the chemoresistance. When VEGFR-2 was knocked out in EA.hy926 cells using the CRISPR-Cas9 system, the cytarabine-induced apoptosis of AML cells did not significantly change compared with that of wild-type cells. Thus, coculture-induced chemoresistance appears to be independent of VEGF-A/VEGFR-2 signaling. When the transwell, a coculturing device, separated the AML cells from the EA.hy926 cells in a monolayer, the coculture-induced chemoresistance was inhibited. Given that the migration of VEGF-A/VEGFR-2 signaling-dependent endothelial cells is necessary for the endothelial niche formation in the bone marrow, VEGF-A/VEGFR-2 signaling contributes to chemoresistance by mediating the niche formation process, but not to the chemoresistance of AML cells in the niche.

Crucial contribution of GPR56/ADGRG1, expressed by breast cancer cells, to bone metastasis formation

From a mouse triple-negative breast cancer cell line, 4T1, we previously established 4T1.3 clone with a high capacity to metastasize to bone after its orthotopic injection into mammary fat pad of immunocompetent mice. Subsequent analysis demonstrated that the interaction between cancer cells and fibroblasts in a bone cavity was crucial for bone metastasis focus formation arising from orthotopic injection of 4T1.3 cells. Here, we demonstrated that a member of the adhesion G-protein-coupled receptor (ADGR) family, G-protein-coupled receptor 56 (GPR56)/adhesion G-protein-coupled receptor G1 (ADGRG1), was expressed selectively in 4T1.3 grown in a bone cavity but not under in vitro conditions. Moreover, fibroblasts present in bone metastasis sites expressed type III collagen, a ligand for GPR56/ADGRG1. Consistently, GPR56/ADGRG1 proteins were detected in tumor cells in bone metastasis foci of human breast cancer patients. Deletion of GPR56/ADGRG1 from 4T1.3 cells reduced markedly intraosseous tumor formation upon their intraosseous injection. Conversely, intraosseous injection of GPR56/ADGRG1-transduced 4T1, TS/A (mouse breast cancer cell line), or MDA-MB-231 (human breast cancer cell line) exhibited enhanced intraosseous tumor formation. Furthermore, we proved that the cleavage at the extracellular region was indispensable for GPR56/ADGRG1-induced increase in breast cancer cell growth upon its intraosseous injection. Finally, inducible suppression of Gpr56/Adgrg1 gene expression in 4T1.3 cells attenuated bone metastasis formation with few effects on primary tumor formation in the spontaneous breast cancer bone metastasis model. Altogether, GPR56/ADGRG1 can be a novel target molecule to develop a strategy to prevent and/or treat breast cancer metastasis to bone.

Optimization of prediction methods for risk assessment of pathogenic germline variants in the Japanese population

Predicting pathogenic germline variants (PGVs) in breast cancer patients is important for selecting optimal therapeutics and implementing risk reduction strategies. However, PGV risk factors and the performance of prediction methods in the Japanese population remain unclear. We investigated clinicopathological risk factors using the Tyrer‐Cuzick (TC) breast cancer risk evaluation tool to predict BRCA PGVs in unselected Japanese breast cancer patients (n = 1,995). Eleven breast cancer susceptibility genes were analyzed using target‐capture sequencing in a previous study; the PGV prevalence in BRCA1, BRCA2, and PALB2 was 0.75%, 3.1%, and 0.45%, respectively. Significant associations were found between the presence of BRCA PGVs and early disease onset, number of familial cancer cases (up to third‐degree relatives), triple‐negative breast cancer patients under the age of 60, and ovarian cancer history (all P < .0001). In total, 816 patients (40.9%) satisfied the National Comprehensive Cancer Network (NCCN) guidelines for recommending multigene testing. The sensitivity and specificity of the NCCN criteria for discriminating PGV carriers from noncarriers were 71.3% and 60.7%, respectively. The TC model showed good discrimination for predicting BRCA PGVs (area under the curve, 0.75; 95% confidence interval, 0.69‐0.81). Furthermore, use of the TC model with an optimized cutoff of TC score ≥0.16% in addition to the NCCN guidelines improved the predictive efficiency for high‐risk groups (sensitivity, 77.2%; specificity, 54.8%; about 11 genes). Given the influence of ethnic differences on prediction, we consider that further studies are warranted to elucidate the role of environmental and genetic factors for realizing precise prediction.

Mutation of OUR1/OsbZIP1, which encodes a member of the basic leucine zipper transcription factor family, promotes root development in rice through repressing auxin signaling

A well-developed root system is essential for efficient water uptake, particularly in drought-prone environments. However, the molecular mechanisms underlying the promotion of root development are poorly understood. We identified and characterized a rice mutant, outstanding rooting1 (our1), which exhibited a well-developed root system. The our1 mutant displayed typical auxin-related phenotypes, including elongated seminal root and defective gravitropism. Seminal root elongation in the our1 mutant was accelerated via the promotion of cell division and elongation. In addition, compared with the wild type, the density of short and thin lateral roots (S-type LRs) was reduced in the our1 mutant, whereas that of long and thick LRs (L-type LRs) was increased. Expression of OUR1, which encodes OsbZIP1, a member of the basic leucine zipper transcription factor family, was observed in the seminal root tip and sites of LR emergence, wherein attenuation of reporter gene expression levels controlled by the auxin response promoter DR5 was also observed in the our1 mutant. Taken together, our results indicate that the our1 gene promotes root development by suppressing auxin signaling, which may be a key factor contributing to an improvement in root architecture.

Morpho-physiological and molecular mechanisms of phenotypic root plasticity for rice adaptation to water stress conditions

Different types of water stress severely affect crop production, and the plant root system plays a critical role in stress avoidance. In the case of rice, a cereal crop cultivated under the widest range of soil hydrologic conditions, from irrigated anaerobic conditions to rainfed conditions, phenotypic root plasticity is of particular relevance. Recently, important plastic root traits under different water stress conditions, and their physiological and molecular mechanisms have been gradually understood. In this review, we summarize these plastic root traits and their contributions to dry matter production through enhancement of water uptake under different water stress conditions. We also discuss the physiological and molecular mechanisms regulating the phenotypic plasticity of root systems.

The promoted lateral root 1 (plr1) mutation is involved in reduced basal shoot starch accumulation and increased root sugars for enhanced lateral root growth in rice

Lateral roots (LRs) are indispensable for plant growth, adaptability and productivity. We previously reported a rice mutant, exhibiting a high density of thick and long LRs (L-type LRs) with long parental roots and herein referred to as promoted lateral root1 (plr1). In this study, we describe that the mutant exhibited decreased basal shoot starch accumulation, suggesting that carbohydrates might regulate the mutant root phenotype. Further analysis revealed that plr1 mutation gene regulated reduced starch accumulation resulting in increased root sugars for the regulation of promoted LR development. This was supported by the exogenous glucose application that promoted L-type LRs. Moreover, nitrogen (N) application was found to reduce basal shoot starch accumulation in both plr1 mutant and wild-type seedlings, which was due to the repressed expression of starch biosynthesis genes. However, unlike the wild-type that responded to N treatment only at seedling stage, the plr1 mutant regulated LR development under low to increasing N levels, both at seedling and higher growth stages. These results suggest that plr1 mutation gene is involved in reduced basal shoot starch accumulation and increased root sugar level for the promotion of L-type LR development, and thus would be very useful in improving rice root architecture.

A GWAS approach to find SNPs associated with salt removal in rice leaf sheath

BACKGROUND AND AIMS

The ability for salt removal at the leaf sheath level is considered to be one of the major mechanisms associated with salt tolerance in rice. Thus, understanding the genetic control of the salt removal capacity in leaf sheaths will help improve the molecular breeding of salt-tolerant rice varieties and speed up future varietal development to increase productivity in salt-affected areas. We report a genome-wide association study (GWAS) conducted to find single nucleotide polymorphisms (SNPs) associated with salt removal in leaf sheaths of rice.

METHODS

In this study, 296 accessions of a rice (Oryza sativa) diversity panel were used to identify salt removal-related traits and conduct GWAS using 36 901 SNPs. The sheath:blade ratio of Na+ and Cl- concentrations was used to determine the salt removal ability in leaf sheaths. Candidate genes were further narrowed via Gene Ontology and RNA-seq analysis to those whose putative function was likely to be associated with salt transport and were up-regulated in response to salt stress.

KEY RESULTS

For the association signals of the Na+ sheath:blade ratio, significant SNPs were found only in the indica sub-population on chromosome 5. Within candidate genes found in the GWAS study, five genes were upregulated and eight genes were downregulated in the internal leaf sheath tissues in the presence of salt stress.

CONCLUSIONS

These GWAS data imply that rice accessions in the indica variety group are the main source of genes and alleles associated with Na+ removal in leaf sheaths of rice under salt stress.

Tissue-specific expression analysis of Na+ and Cl- transporter genes associated with salt removal ability in rice leaf sheath

BACKGROUND

A significant mechanism of salt-tolerance in rice is the ability to remove Na⁺ and Cl^- in the leaf sheath, which limits the entry of these toxic ions into the leaf blade. The leaf sheath removes Na⁺ mainly in the basal parts, and Cl^- mainly in the apical parts. These ions are unloaded from the xylem vessels in the peripheral part and sequestered into the fundamental parenchyma cells at the central part of the leaf sheath.

RESULTS

This study aimed to identify associated Na⁺ and Cl^- transporter genes with this salt removal ability in the leaf sheath of rice variety FL 478. From 21 known candidate Na⁺ and Cl^- transporter rice genes, we determined the salt responsiveness of the expression of these genes in the basal and apical parts, where Na⁺ or Cl^- ions were highly accumulated under salinity. We also compared the expression levels of these transporter genes between the peripheral and central parts of leaf sheaths. The expression of 8 Na⁺ transporter genes and 3 Cl^- transporter genes was up-regulated in the basal and apical parts of leaf sheaths under salinity. Within these genes, OsHKT1;5 and OsSLAH1 were expressed highly in the peripheral part, indicating the involvement of these genes in Na⁺ and Cl^- unloading from xylem vessels. OsNHX2, OsNHX3, OsNPF2.4 were expressed highly in the central part, which suggests that these genes may function in sequestration of Na⁺ and Cl^- in fundamental parenchyma cells in the central part of leaf sheaths under salinity. Furthermore, high expression levels of 4 candidate genes under salinity were associated with the genotypic variation of salt removal ability in the leaf sheath.

CONCLUSIONS

These results indicate that the salt removal ability in rice leaf sheath may be regulated by expressing various Na⁺ or Cl^- transporter genes tissue-specifically in peripheral and central parts. Moreover, some genes were identified as candidates whose expression levels were associated with the genotypic variation of salt removal ability in the leaf sheath. These findings will enhance the understanding of the molecular mechanism of salt removal ability in rice leaf sheath, which is useful for breeding salt-tolerant rice varieties.

Nanoparticle-Mediated Delivery of 2-Deoxy-D-Glucose Induces Antitumor Immunity and Cytotoxicity in Liver Tumors in Mice

BACKGROUND & AIMS

Immune checkpoint inhibitors have shed light on the importance of antitumor immunity as a therapeutic strategy for hepatocellular carcinoma (HCC). The altered glucose metabolism known as the Warburg effect recently has gained attention as a cancer immune-resistance mechanism. Considering glycolysis inhibitors as therapeutic agents, their specific delivery to cancer cells is critical not to induce adverse effects. Thus, we investigated antitumor effects of a glycolysis inhibitor, consisting of 2-deoxy-D-glucose (2DG)-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (2DG-PLGA-NPs), against hepatocellular carcinoma in mice.

METHODS

The antitumor effects of 2DG-PLGA-NPs were examined using hepatoma cell lines, xenograft tumors, and hepatocarcinogenic and syngeneic mouse models.

RESULTS

The 2DG-PLGA-NPs induced cytotoxic effects and antitumor immunity through enhanced T-cell trafficking. In addition, 2DG-PLGA-NPs induced decreased lactate production and increased interferon-γ-positive T cells in liver tumors. Human CD8⁺ T cells cocultured with 2DG-PLGA-NP-treated Huh7 cells showed their increased interferon-γ production and glucose uptake compared with the CD8⁺ T cells co-cultured with PLGA-NP-treated Huh7 cells. Chemotaxis of CD8⁺ T cells was suppressed by lactate and enhanced by glucose. Interferon-γ enhanced CD8⁺ T-cell chemotaxis in both an autocrine and paracrine manner. Notably, the 2DG-PLGA-NPs augmented chemokine (CXCL9/CXCL10) production in liver tumors via interferon-γ-Janus kinase-signal transducers and activator of transcription pathway and 5' adenosine monophosphate-activated protein kinase-mediated suppression of histone H3 lysine 27 trimethylation. These 2DG-PLGA-NPs not only amplified antitumor effects induced by sorafenib or an anti-programmed death-1 antibody, but also suppressed anti-programmed death-1-resistant tumors.

CONCLUSIONS

The newly developed 2DG-PLGA-NPs showed antitumor immunity and cytotoxicity in liver tumors in mice, suggesting the potential of 2DG-PLGA-NPs for future clinical applications.

Genetic and clinical landscape of breast cancers with germline BRCA1/2 variants

The genetic and clinical characteristics of breast tumors with germline variants, including their association with biallelic inactivation through loss-of-heterozygosity (LOH) and second somatic mutations, remain elusive. We analyzed germline variants of 11 breast cancer susceptibility genes for 1,995 Japanese breast cancer patients, and identified 101 (5.1%) pathogenic variants, including 62 BRCA2 and 15 BRCA1 mutations. Genetic analysis of 64 BRCA1/2-mutated tumors including TCGA dataset tumors, revealed an association of biallelic inactivation with more extensive deletions, copy neutral LOH, gain with LOH and younger onset. Strikingly, TP53 and RB1 mutations were frequently observed in BRCA1- (94%) and BRCA2- (9.7%) mutated tumors with biallelic inactivation. Inactivation of TP53 and RB1 together with BRCA1 and BRCA2, respectively, involved LOH of chromosomes 17 and 13. Notably, BRCA1/2 tumors without biallelic inactivation were indistinguishable from those without germline variants. Our study highlights the heterogeneity and unique clonal selection pattern in breast cancers with germline variants.

Yukiko Inagaki-Kawata et al. report an analysis of germline variants in breast cancer susceptibility genes in 1,995 Japanese breast cancer patients. They find that 5.1% of the patients carry germline variants in cancer-linked genes and investigate the characteristics of patients with germline mutations in BRCA1/2.

Inhibitory Effect of Eicosapentaenoic Acid on the Migration of the Esophageal Squamous Cell Carcinoma Cell Line TE-1

BACKGROUND/AIM

Eicosapentaenoic acid (EPA) inhibits NF-ĸB activation and IL-6 production in TE-1 esophageal cancer cells. NF-ĸB is related to cancer cell migration. The aim of this study is to evaluate whether EPA has a metastasis suppressing effect. Herein, we investigated EPA-treated TE-1 cell migration using TAXIScan.

MATERIALS AND METHODS

EZ-TAXIScan® was used to verify whether EPA inhibits cancer cell chemotaxis.

RESULTS

Using 50% fetal bovine serum (chemoattractant) without EPA (positive control), average velocity was 0.306±0.084 μm/min compared to 0.162±0.067 μm/min without chemoattraction (negative control). Directionalities of positive and negative controls were 1.039±0.152 and 0.488±0.251 radians, respectively, indicating a significant increase in migration of the positive control compared to that of the negative control. Average velocities were 0.306±0.084 (no EPA), 0.288±0.078 (100 μM EPA), and 0.240±0.054 200 μM (EPA) μm/min, indicating that EPA reduced velocity dose-dependently. Average directionalities were 1.039±0.152 (no EPA), 0.967±0.164 (100 μM EPA), and 0.901±0.146 (200 μM EPA) radians, indicating that EPA also inhibited directionality dose-dependently.

CONCLUSION

EPA suppresses directional migration of TE-1 cells.

Constitutive activity of NADPH oxidase 1 (Nox1) that promotes its own activity suppresses the colon epithelial cell migration

Superoxide producing NADPH oxidase 1 (Nox1), abundantly expressed in the colon epithelium, plays a crucial role in mucosal host defenses. In this study, we found that pre-treatment of cells with edaravone, a free radical scavenger, inhibited Nox1 constitutive activity even after washout without affecting Nox1 trafficking to the plasma membrane and membrane recruitment of the cytosolic regulators Noxo1 and Noxa1. These results suggest that a Nox1-derived product is involved in the step that initiates the electron transfer reaction after the formation of the Nox1-Noxo1-Noxa1 complex. Furthermore, we show that the mean migration directionality and velocity of epithelial cells were significantly enhanced by the inhibition of constitutive Nox1 activity. Thus, the constitutive Nox1 activity limits undesired cell migration in resting cells while participating in a positive feedback loop toward its own oxidase activity.

The rRNA synthesis inhibitor CX-5461 may induce autophagy that inhibits anticancer drug-induced cell damage to leukemia cells

Autophagy induced in cancer cells during chemotherapy is classified into two types, which differ depending on the kind of cells or anticancer drugs. The first type of autophagy contributes to the death of cells treated with drugs. In contrast, the second type plays a crucial role in preventing anticancer drug-induced cell damages; the use of an autophagy inhibitor is considered effective in improving the efficacy of chemotherapy. Thus, it is important to determine which type of autophagy is induced during chemotherapy. Here, we showed that a novel inhibitor of RNA polymerase I, suppresses growth, induces cell cycle arrest and promotes apoptosis in leukemia cell lines. The number of apoptotic cells induced by co-treatment with CX-5461 and chloroquine, an autophagy inhibitor, increased compared with CX-5461 alone. Thus, the autophagy which may be induced by CX-5461 was the second type.

The NADPH oxidase NOX4 promotes the directed migration of endothelial cells by stabilizing vascular endothelial growth factor receptor 2 protein

Directed migration of endothelial cells (ECs) is an important process during both physiological and pathological angiogenesis. The binding of vascular endothelial growth factor (VEGF) to VEGF receptor-2 (VEGFR-2) on the EC surface is necessary for directed migration of these cells. Here, we used TAXIScan, an optically accessible real-time horizontal cell dynamics assay approach, and demonstrate that reactive oxygen species (ROS)-producing NADPH oxidase 4 (NOX4), which is abundantly expressed in ECs, mediates VEGF/VEGFR-2-dependent directed migration. We noted that a continuous supply of endoplasmic reticulum (ER)-retained VEGFR-2 to the plasma membrane is required to maintain VEGFR-2 at the cell surface. siRNA-mediated NOX4 silencing decreased the ER-retained form of VEGFR-2, resulting in decreased cell surface expression levels of the receptor. We also found that ER-localized NOX4 interacts with ER-retained VEGFR-2 and thereby stabilizes this ER-retained form at the protein level in the ER. We conclude that NOX4 contributes to the directed migration of ECs by maintaining VEGFR-2 levels at their surface.

Neuroplastinβ-mediated upregulation of solute carrier family 22 member 18 antisense (SLC22A18AS) plays a crucial role in the epithelial-mesenchymal transition, leading to lung cancer cells' enhanced motility

Our recent study revealed an important role of the neuroplastin (NPTN)β downstream signal in lung cancer dissemination in the lung. The molecular mechanism of the signal pathway downstream of NPTNβ is a serial activation of the key molecules we identified: tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) adaptor, nuclear factor (NF)IA/NFIB heterodimer transcription factor, and SAM pointed-domain containing ETS transcription factor (SPDEF). The question of how dissemination is controlled by SPDEF under the activated NPTNβ has not been answered. Here, we show that the NPTNβ-SPDEF-mediated induction of solute carrier family 22 member 18 antisense (SLC22A18AS) is definitely required for the epithelial-mesenchymal transition (EMT) through the NPTNβ pathway in lung cancer cells. In vitro, the induced EMT is linked to the acquisition of active cellular motility but not growth, and this is correlated with highly disseminative tumor progression in vivo. The publicly available data also show the poor survival of SLC22A18AS-overexpressing lung cancer patients. Taken together, these data highlight a crucial role of SLC22A18AS in lung cancer dissemination, which provides novel input of this molecule to the signal cascade of NPTNβ. Our findings contribute to a better understanding of NPTNβ-mediated lung cancer metastasis.

WEG1, which encodes a cell wall hydroxyproline-rich glycoprotein, is essential for parental root elongation controlling lateral root formation in rice

Lateral roots (LRs) determine the overall root system architecture, thus enabling plants to efficiently explore their underground environment for water and nutrients. However, the mechanisms regulating LR development are poorly understood in monocotyledonous plants. We characterized a rice mutant, wavy root elongation growth 1 (weg1), that produced higher number of long and thick LRs (L-type LRs) formed from the curvatures of its wavy parental roots caused by asymmetric cell growth in the elongation zone. Consistent with this phenotype, was the expression of the WEG1 gene, which encodes a putative member of the hydroxyproline-rich glycoprotein family that regulates cell wall extensibility, in the root elongation zone. The asymmetric elongation growth in roots is well known to be regulated by auxin, but we found that the distribution of auxin at the apical region of the mutant and the wild-type roots was symmetric suggesting that the wavy root phenotype in rice is independent of auxin. However, the accumulation of auxin at the convex side of the curvatures, the site of L-type LR formation, suggested that auxin likely induced the formation of L-type LRs. This was supported by the need of a high amount of exogenous auxin to induce the formation of L-type LRs. These results suggest that the MNU-induced weg1 mutated gene regulates the auxin-independent parental root elongation that controls the number of likely auxin-induced L-type LRs, thus reflecting its importance in improving rice root architecture.

Anti-Allergic and Anti-Inflammatory Effects and Molecular Mechanisms of Thioredoxin on Respiratory System Diseases

Significance: The pathogenesis and progression of allergic inflammation in the respiratory system are closely linked to oxidative stress. Thioredoxin (TRX) is an essential redox balance regulator in organisms and is induced by various oxidative stress factors, including ultraviolet rays, radiation, oxidation, viral infections, ischemia reperfusion, and anticancer agents. Recent Advances: We demonstrated that systemic administration and transgenic overexpression of TRX is useful in a wide variety of in vivo inflammatory respiratory diseases models, such as viral pneumonia, interstitial lung disease, chronic obstructive pulmonary disease, asthma, acute respiratory distress syndrome, and obstructive sleep apnea syndrome, by removing reactive oxygen species, blocking production of inflammatory cytokines, inhibiting migration and activation of neutrophils and eosinophils, and regulating the cellular redox status. In addition, TRX's anti-inflammatory mechanism is different from the mechanisms associated with anti-inflammatory agents, such as glucocorticoids, which regulate the inflammatory reaction in association with suppressing immune responses. Critical Issues: Understanding the molecular mechanism of TRX is very helpful for understanding the role of TRX in respiratory diseases. In this review, we show the protective effect of TRX in various respiratory diseases. In addition, we discuss its anti-allergic and anti-inflammatory molecular mechanism in detail. Future Directions: The application of TRX may be useful for treating respiratory allergic inflammatory disorders. Antioxid. Redox Signal. 32, 785-801.

Efficacy and safety of once-weekly exenatide after switching from twice-daily exenatide in patients with type 2 diabetes

AIMS/INTRODUCTION

To evaluate the efficacy and safety of once-weekly (q.w.) extended-release exenatide after switching from twice-daily (b.i.d.) exenatide in patients with type 2 diabetes.

MATERIALS AND METHODS

This was an investigator-initiated, prospective, single-arm, multicenter study. Individuals with type 2 diabetes who had been treated with exenatide b.i.d. for at least 3 months were enrolled and switched to exenatide q.w. for 24 weeks. The primary end-point was change in HbA1c at week 24 to test the glucose-lowering effect of exenatide q.w. versus exenatide b.i.d.

RESULTS

A total of 58 Japanese individuals with type 2 diabetes completed the study. Glycated hemoglobin was reduced by 0.2% at week 24 (7.2 ± 1.2% vs 7.0 ± 1.2% [56 ± 13 vs 53 ± 13 mmol/mol], 95% confidence interval -0.4 to -0.03%, P < 0.005 for non-inferiority, P = 0.01 for superiority). Fasting plasma glucose was reduced by 12 mg/dL at week 24 (154 ± 46 vs 142 ± 46 mg/dL, P = 0.02). β-Cell function assessed by homeostasis model assessment of β-cell function and C-peptide index was significantly improved at week 24. The incidence of self-reported hypoglycemia was reduced, and treatment satisfaction assessed by the Diabetes Treatment Satisfaction Questionnaire and Diabetes Medication Satisfaction Questionnaire was improved at week 24, with no change in body weight. There was no serious adverse event related to the study drug.

CONCLUSIONS

Switching from exenatide b.i.d. to exenatide q.w. resulted in a reduction in glycated hemoglobin, fasting plasma glucose and the incidence of hypoglycemia, and improvement in β-cell function and treatment satisfaction in patients with type 2 diabetes. These findings will be useful for selecting optimal treatment in individuals with type 2 diabetes.

Abstract P2-10-12: Relationship between predicted risks of carrying breast cancer susceptibility genes and the presence of germline variants in Japanese patients with primary breast cancer

Background: Breast cancer risk models are used to predict the risk of carrying a variant, for one of the most common breast cancer susceptibility genes such as BRCA1 and BRCA2, and the lifetime risk of developing breast cancer. The prediction of harboring a germline variant of the BRCA gene and the development of breast or ovarian cancer over time affects the decision-making for undergoing genetic testing and screening using imaging techniques as the common practice. For instance, the American Cancer Society and the National Comprehensive Cancer Network (NCCN) recommends screening using MRI in women with 20% or greater lifetime risk of having breast cancer. We aimed to investigate the prediction of these risks in Japanese women, particularly on the relationship between the presence of pathogenic germline variants and breast cancer susceptibility genes, using a cohort of 1016 primary breast cancer patients.

Patients and Methods: We analyzed a cohort of Japanese patients with primary breast cancer who were treated at the Kyoto University Hospital and the related institutions or hospitals from the period of 2011 to 2016. The germline variants were examined for a set of 13 breast cancer susceptibility genes, using targeted-capture sequencing of pooled DNA, and it was found that 66 out of 1016 patients had pathogenic variants. These included 11 functionally well-established genes (BRCA1, BRCA2, TP53, PTEN, CDH1, STK11, NF1, PALB2, ATM, CHEK2, and NBN) and two additional genes (BARD1 and BRIP1), which are recommended for the screening of high-risk patients with hereditary breast cancer in the NCCN guidelines. Using this cohort, we studied the association of the calculated risk of carrying a germline variant of BRCA1/ BRCA2, using the Tyrer-Cuzick model Breast Cancer Risk Evaluation Tool, within the laboratory germline test results.

Results: Pathogenic germline variants of BRCA1/ BRCA2 were carried by 54 (5.3%) out of the 1016 patients (12 cases of BRCA1 and 42 cases of BRCA2). According to the NCCN guidelines, which focus on Genetic/ Familial High-Risk Assessment: Breast and Ovarian, it was found that 500 out of 1016 (49.2%)patients were categorized for considering germline testing. In fact, 38 (7.6%) of the 500 patients, harbored a pathogenic germline variant of BRCA1/ BRCA2. In the remaining 516 patients, 16 (3.1%) harbored the pathogenic germline variant of BRCA1/ BRCA2. The predictive risks of the Tyrer-Cuzick model Breast Cancer Risk Evaluation Tool were recorded as follows: Area under the ROC curve, BRCA1 (area 0.750, 95% CI- 0.581-0.919), BRCA2 (area 0.741, 95% CI- 0.661-0.820), BRCA1 or BRCA2 (Area 0.749, 95% CI: 0.675-0.822), suggesting that the Tyrer-Cuzick model may be useful for the Japanese population. In the mammography breast density analysis, 484 patients showed almost entirely fat or scattered fibroglandular breast tissue, and 362 cases had heterogeneous or extreme fibroglandular breast tissue. In this study, the correlations of breast tissue density with age and breast or ovarian cancer familial history have been reported in greater detail.

Discussion and Conclusions: In a retrospective cohort of 1016 Japanese patients with primary breast cancer, 5.3% had pathogenic germline variants of BRCA1/ BRCA2. In a group recommended by NCCN guidelines for considering genetic testing, the BRCA1/ BRCA2 variant rate was 7.6%. Predictive risks calculated by the Tyrer-Cuzick model similar with the known data. Further data are reported.

Citation Format: Noriko Senda, Nobuko Kawaguchi-Sakita, Masahiro Kawashima, Yukiko Inagaki-Kawata, Kenichi Yoshida, Tomomi Nishimura, Masahiro Takada, Eiji Suzuki, Yuki Kataoka, Fumiaki Sato, Yoshiaki Matsumoto, Masae Torii, Hiroshi Yoshibayashi, Kazuhiro Yamagami, Shigeru Tsuyuki, Akira Yamauchi, Nobuhiko Shinkura, Hironori Kato, Yoshio Moriguchi, Ryuji Okamura, Norimichi Kan, Hirofumi Suwa, Shingo Sakata, Susumu Mashima, Fumiaki Yotsumoto, Tsuyoshi Tachibana, Mitsuru Tanaka, Takashi Inamoto, Masahiro Sugimoto, Seishi Ogawa, Masakazu Toi. Relationship between predicted risks of carrying breast cancer susceptibility genes and the presence of germline variants in Japanese patients with primary breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-10-12.

Evaluation of rice grain yield and yield components of Nona Bokra chromosome segment substitution lines with the genetic background of Koshihikari, in a saline paddy field

The ability to tolerate salt differs with the growth stages of rice and thus the yield components that are determined during various growth stages, are differentially affected by salt stress. In this study, we utilized chromosome segment substitution lines (CSSLs) from Nona Bokra, a salt-tolerant indica landrace, with the genetic background of Koshihikari, a salt-susceptible japonica variety. These were screened to find superior CSSLs under long-term saline conditions that showed higher grain yield and yield components in comparison to Koshihikari. One-month-old seedlings were transplanted into a paddy field without salinity. These were allowed to establish for 1 month further, then the field was flooded, with saline water maintained at 7.41 dS m^-1 salinity until harvest. The experiments were performed twice, once in 2015 and a targeted study in 2016. Salt tolerance of growth and reproductive stage parameters was evaluated as the Salt Effect Index (SEI) which was computed as the difference in each parameter within each line between control and saline conditions. All CSSLs and Koshihikari showed a decrease in grain yield and yield components except panicle number under salinity. SL538 showed a higher SEI for grain yield compared with Koshihikari under salinity throughout the two experiments. This was attributed to the retained grain filling and harvest index, yet the mechanism was not due to maintaining Na⁺, Cl^- and K⁺ homeostasis. Few other CSSLs showed greater SEI for grain weight under salinity compared with Koshihikari, which might be related to low concentration of Na⁺ in leaves and panicles. These data indicate that substitution of different Nona Bokra chromosome segments independently contributed to the maintenance of grain filling and grain weight of Koshihikari under saline conditions.

Effectiveness and safety of surgical glove compression therapy as a prophylactic method against nanoparticle albumin-bound-paclitaxel-induced peripheral neuropathy

BACKGROUND

We have developed a surgical glove (SG)-compression therapy and reported that this method significantly reduced the overall occurrence of grade 2 or higher nanoparticle albumin-bound-paclitaxel (nab-PTX)-induced peripheral neuropathy (PN) from 76.1% to 21.4%. In this multicenter single-arm confirmatory study, we investigated the efficacy and safety of SG-compression therapy for the prevention of nab-PTX-induced PN, compared with the incidence of grade 2 or higher PN in published literature as controls.

PATIENTS AND METHODS

Primary breast cancer patients who received 260 mg/m² of nab-PTX were eligible for this study. Patients wore two SGs (one size smaller than the tight-fitting size) in each hand for 90 min. PN was evaluated at each treatment cycle using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 and the Patient Neurotoxicity Questionnaire (PNQ). The temperature of each fingertip was measured using thermography.

RESULTS

Between October 2016 and June 2017, 58 patients were evaluated. The incidence of CTCAE grade 2 or higher PN was as low as 13.8% following SG-compression therapy. A goodness-of-fit test proved that the overall incidence of 13.8% grade 2 or higher PN in this study was comparable to the hypothesis-predicted value (13%). No adverse events, including compression intolerance or skin disorders caused by use of SG, were observed. SG-compression therapy significantly reduced the temperature of each fingertip by 1.3°C-2.3 °C compared to pre-chemotherapy level.

CONCLUSIONS

This study suggested the safety and efficacy of SG-compression therapy for the amelioration of CIPN.

CLINICAL TRIAL NUMBER

UMIN 000024836.

Abstract 2188: Comparing effects of small molecular weight compounds on proliferation and chemotaxis of pancreatic cancer cells

Background & Aims: The new therapy for pancreatic cancer which has the poorest prognosis among malignant tumors is high demand nowadays. The overall 5-year survival rate in all stages of this type of cancer is less than 5%, even with the multimodality therapy, including surgery, chemotherapy and radiotherapy. Although gemcitabine (GEM) is a key drug in the treatment of advanced pancreatic cancer, the therapeutic effect is limited because of drug resistance. Heat shock protein 90 (HSP90) is known to be overexpressed in several types of cancer cells, and its inhibition has shown promise in the treatment of solid malignancies. Src kinases work as a signal switch for multiple molecular signal transduction pathways. The objective of this study is to evaluate an antitumor effect of three kinds of small molecular weight compounds (antimetabolite Gemcitabine, HSP90 inhibitor NVP-AUY922, and Src kinase inhibitor Dasatinib) on tumor growth and chemotaxis in pancreatic cancer cell lines. Methods: Pancreatic cancer cell lines were treated with each of the 3 compounds to examine the effect on proliferation assay, apoptosis assay, Western blotting, and chemotaxis assay. Results: Of these compounds, HSP90 inhibitor inhibited cell proliferation in pancreatic cancer cells best in a dose- and time-dependent manner. Growth inhibitory effect of HSP90 inhibitor for pancreatic cancer cells were highest of the three. Further, HSP90 inhibitor inhibited the growth of gemcitabine sensitive and resistant pancreatic cancer cell lines. With flowcytometry and immunostaining, HSP90 inhibitor had higher apoptosis-inducing effect than gemcitabine. In the chemotaxis assay, HSP90 inhibitor inhibited the migration of pancreatic cancer cell best in the three compounds. In western blotting, HSP90 inhibitor suppressed the expression of multiple receptor tyrosine kinase proteins as well as the signal transduction in PI3K-Akt and RAS-MAPK pathways. Conclusion: In this study, HSP90 inhibitor was the best of 3 small molecular compounds and has proven effective in gemcitabine sensitive and resistant pancreatic cancer. The HSP90 inhibitor is useful as an antitumor drug by inhibiting proliferation and chemotaxis of pancreatic cancer cells through multiple kinase pathways.

Citation Format: Masahiro Yamamura, Akira Yamauchi, Naoki Katase, Masakiyo Sakaguchi, Yosuke Katata, Hiroaki Tanioka, Makoto Okawaki, Takeshi Nagasaka, Yoshiyuki Yamaguchi. Comparing effects of small molecular weight compounds on proliferation and chemotaxis of pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2188.

Fundamental parenchyma cells are involved in Na+ and Cl- removal ability in rice leaf sheath

Salt sensitivity in rice plants is associated with the accumulated amount of Na+ and Cl- in shoots and, more significantly, in photosynthetic tissues. Therefore, salt removal ability at the leaf sheath level is an important mechanism of salt tolerance. In the present study we attempted to determine whether rice leaf sheaths excluded Cl- as well as Na+, and to identify the tissues that were involved in the removal ability of both ions. In two rice genotypes, salt-tolerant FL478 and -sensitive IR29, leaf sheaths excluded Na+ and Cl- under NaCl treatment as estimated using their sheath:blade ratios. The sheath:blade ratio of Na+ but not of Cl-, was increased by NaCl treatment. Under NaCl treatment, Na+ concentration was higher in the basal leaf sheath, whereas Cl- concentration was higher in the middle and tip parts. At the tissue level, fundamental parenchyma cells of leaf sheaths retained the highest amounts of Na and Cl when treated with high amount of NaCl. These results imply that the leaf sheath potentially functions to remove excess Na+ and Cl- from xylem vessels in different locations along the axis, with the fundamental parenchyma cells of leaf sheaths being involved in over-accumulation of both Na+ and Cl-.

Melanoma cell adhesion molecule is the driving force behind the dissemination of melanoma upon S100A8/A9 binding in the original skin lesion

Since metastasis accounts for the majority of cancer-associated deaths, studies on the mechanisms of metastasis are needed to establish innovative strategies for cancer treatment. We previously reported that melanoma cell adhesion molecule (MCAM) functions as a critical receptor for S100A8/A9, and binding of S100A8/A9 to MCAM results in the migration of melanoma cells to lung tissue. However, the critical role of MCAM in the original melanoma skin lesion is still not clear. In this study, we aimed to determine the importance of the S100A8/A9-MCAM axis in melanoma dissemination in a skin lesion as a critical early step for metastasis. Mechanistic studies revealed the downstream signaling of MCAM that signaled the induction of metastasis. S100A8/A9-MCAM binding activates mitogen-activated protein kinase kinase kinase 8 (MAP3K8), also termed TPL2, leading to strong activation of the transcription factor ETV4 and subsequent induction of matrix metalloproteinase-25 (MMP25), and finally to induction of melanoma lung tropic metastasis. Collectively, our results demonstrate a crucial role of the S100A8/A9-MCAM signaling axis in metastatic onset of melanoma cells and indicate that strategies targeting the identified pathway may be useful for the establishment of innovative anti-cancer therapies.

Critical role of the MCAM-ETV4 axis triggered by extracellular S100A8/A9 in breast cancer aggressiveness

Metastatic breast cancer is the leading cause of cancer-associated death in women. The progression of this fatal disease is associated with inflammatory responses that promote cancer cell growth and dissemination, eventually leading to a reduction of overall survival. However, the mechanism(s) of the inflammation-boosted cancer progression remains unclear. In this study, we found for the first time that an extracellular cytokine, S100A8/A9, accelerates breast cancer growth and metastasis upon binding to a cell surface receptor, melanoma cell adhesion molecule (MCAM). Our molecular analyses revealed an important role of ETS translocation variant 4 (ETV4), which is significantly activated in the region downstream of MCAM upon S100A8/A9 stimulation, in breast cancer progression in vitro as well as in vivo. The MCAM-mediated activation of ETV4 induced a mobile phenotype called epithelial-mesenchymal transition (EMT) in cells, since we found that ETV4 transcriptionally upregulates ZEB1, a strong EMT inducer, at a very high level. In contrast, downregulation of either MCAM or ETV4 repressed EMT, resulting in greatly weakened tumor growth and lung metastasis. Overall, our results revealed that ETV4 is a novel transcription factor regulated by the S100A8/A9-MCAM axis, which leads to EMT through ZEB1 and thereby to metastasis in breast cancer cells. Thus, therapeutic strategies based on our findings might improve patient outcomes.

Upregulation of Mobility in Pancreatic Cancer Cells by Secreted S100A11 Through Activation of Surrounding Fibroblasts

S100A11, a member of the S100 family of proteins, is actively secreted from pancreatic ductal adenocarcinoma (PDAC) cells. However, the role of the extracellular S100A11 in PDAC progression remains unclear. In the present study, we investigated the extracellular role of S100A11 in crosstalking between PDAC cells and surrounding fibroblasts in PDAC progression. An abundant S100A11 secreted from pancreatic cancer cells stimulated neighboring fibroblasts through receptor for advanced glycation end products (RAGE) upon S100A11 binding and was followed by not only an enhanced cancer cell motility in vitro but also an increased number of the PDAC-derived circulating tumor cells (CTCs) in vivo. Mechanistic investigation of RAGE downstream in fibroblasts revealed a novel contribution of a mitogen-activated protein kinase kinase kinase (MAPKKK), tumor progression locus 2 (TPL2), which is required for positive regulation of PDAC cell motility through induction of cyclooxygenase 2 (COX2) and its catalyzed production of prostaglandin E2 (PGE2), a strong chemoattractive fatty acid. The extracellularly released PGE2 from fibroblasts was required for the rise in cellular migration as well as infiltration of their adjacent PDAC cells in a coculture setting. Taken together, our data reveal a novel role of the secretory S100A11 in PDAC disseminative progression through activation of surrounding fibroblasts triggered by the S100A11-RAGE-TPL2-COX2 pathway. The findings of this study will contribute to the establishment of a novel therapeutic antidote to PDACs that are difficult to treat by regulating cancer-associated fibroblasts (CAFs) through targeting the identified pathway.

Convenient methodology for extraction and subsequent selective propagation of mouse melanocytes in culture from adult mouse skin tissue

Mouse melanoma B16-BL6 cells are useful cells for cancer metastatic studies. To understand the metastatic principle at molecular levels, it is necessary to carry out experiments in which cancer cells and their normal counterparts are compared. However, unlike normal human melanocytes, preparation of normal mouse melanocytes is quite difficult due to the lack of marketing and insufficient information on an established protocol for primary culture of mouse melanocytes. In this study, we aimed to establish a convenient method for primary culture of mouse melanocytes on the basis of the protocol for human melanocytes. The main obstacles to preparing pure mouse melanocytes are how to digest mouse skin tissue and how to reduce the contamination of keratinocytes and fibroblasts. The obstacles were overcome by collagenase digestion for skin specimens, short time trypsinization for separating melanocytes and keratinocytes, and use of 12-O-Tetradecanoylphorbol 13-acetate (TPA) and cholera toxin in the culture medium. These supplements act to prevent the proliferation of keratinocytes and fibroblasts, respectively. The convenient procedure enabled us to prepare a pure culture of normal mouse melanocytes. Using enriched normal mouse melanocytes and cancerous B16-BL6 cells, we compared the expression levels of melanoma cell adhesion molecule (MCAM), an important membrane protein for melanoma metastasis, in the cells. The results showed markedly higher expression of MCAM in B16-BL6 cells than in normal mouse melanocytes.

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Collagenase efficiently extracts skin cells.

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Short trypsinization greatly helps an enrichment of mouse melanocytes in culture.

Extracellular S100A11 Plays a Critical Role in Spread of the Fibroblast Population in Pancreatic Cancers

The fertile stroma in pancreatic ductal adenocarcinomas (PDACs) has been suspected to greatly contribute to PDAC progression. Since the main cell constituents of the stroma are fibroblasts, there is crosstalking(s) between PDAC cells and surrounding fibroblasts in the stroma, which induces a fibroblast proliferation burst. We have reported that several malignant cancer cells including PDAC cells secrete a pronounced level of S100A11, which in turn stimulates proliferation of cancer cells via the receptor for advanced glycation end products (RAGE) in an autocrine manner. Owing to the RAGE⁺ expression in fibroblasts, the extracellular abundant S100A11 will affect adjacent fibroblasts. In this study, we investigated the significance of the paracrine axis of S100A11-RAGE in fibroblasts for their proliferation activity. In in vitro settings, extracellular S100A11 induced upregulation of fibroblast proliferation. Our mechanistic studies revealed that the induction is through RAGE-MyD88-mTOR-p70 S6 kinase upon S100A11 stimulation. The paracrine effect on fibroblasts is linked mainly to triggering growth but not cellular motility. Thus, the identified pathway might become a potential therapeutic target to suppress PDAC progression through preventing PDAC-associated fibroblast proliferation.