Thermoelectric signature of quantum critical phase in a doped spin-liquid candidate

Quantum spin liquid is a nontrivial magnetic state of longstanding interest, in which spins are strongly correlated and entangled but do not order; further intriguing is its doped version, which possibly hosts strange metal and unconventional superconductivity. A promising candidate of the doped spin liquid is a triangular-lattice organic conductor, κ-(BEDT-TTF)₄Hg_2.89Br₈, recently found to hold metallicity, spin-liquid-like magnetism, and BEC-like superconductivity. The nature of the metallic state with the spin-liquid behaviour is awaiting to be further clarified. Here, we report the thermoelectric signature that mobile holes in the spin liquid background are in a quantum critical state and it pertains to the BEC-like superconductivity. The Seebeck coefficient divided by temperature, S/T, is enhanced on cooling with logarithmic divergence indicative of quantum criticality. Furthermore, the logarithmic enhancement is correlated with the superconducting transition temperature under pressure variation, and the temperature and magnetic field profile of S/T upon the superconducting transition change with pressure in a consistent way with the previously suggested BEC-BCS crossover. The present results reveal that the quantum criticality in a doped spin liquid emerges in a phase, not at a point, and is involved in the unconventional BEC-like nature.

Structural origins of the unusual thermal stability of amorphous CuxGe50-xTe50(0⩽x⩽33.3)

We have investigated the local atomic structures of several compositions of the amorphous phase of the system Cu_xGe50-xTe₅₀(0⩽x⩽33.3), based on extended x-ray absorption fine-structure as well as anomalous x-ray scattering experiments, and discuss the unusual trend regarding their thermal stability as a function of the Cu content. At low concentrations (x⩽15), Cu atoms tend to agglomerate in flat nanoclusters reminiscent of the crystalline phase of metallic Cu, leading to a more and more Ge-deficient Ge-Te host network structure with growing Cu content and an increasing thermal stability. At higher Cu concentrations (x⩾25), Cu is incorporated into the network, leading to an overall weaker bonding situation which is associated with a decreasing thermal stability.

Liposomal Amphotericin B Formulation Displaying Lipid-Modified Chitin-Binding Domains with Enhanced Antifungal Activity

Fungal infections affect more than one billion people worldwide and cause more than one million deaths per year. Amphotericin B (AmB), a polyene antifungal drug, has been used as the gold standard for many years because of its broad antifungal spectrum, high activity, and low tendency of drug resistance. However, the side effects of AmB, such as nephrotoxicity and hepatotoxicity, have hampered its widespread use, leading to the development of a liposome-type AmB formulation, AmBisome. Herein, we report a simple but highly effective strategy to enhance the antifungal activity of AmBisome with a lipid-modified protein. The chitin-binding domain (LysM) of the antifungal chitinase, Pteris ryukyuensis chitinase A (PrChiA), a small 5.3 kDa protein that binds to fungal cell wall chitin, was engineered to have a glutamine-containing peptide tag at the C-terminus for the microbial transglutaminase (MTG)-catalyzed crosslinking reaction (LysM-Q). LysM-Q was site-specifically modified with a lysine-containing lipid peptide substrate of MTG with a palmitoyl moiety (Pal-K). The resulting palmitoylated LysM (LysM-Pal) exhibited negligible cytotoxicity to mammalian cells and can be easily anchored to yield LysM-presenting AmBisome (LysM-AmBisome). LysM-AmBisome exhibited a dramatic enhancement of antifungal activity toward Trichoderma viride and Cryptococcus neoformans, demonstrating the marked impact of displaying a cell-wall binder protein on the targeting ability of antifungal liposomal formulations. Our simple strategy with enzymatic protein lipidation provides a potent approach to upgrade other types of lipid-based drug formulations.

Preparation of amphotericin B-loaded hybrid liposomes and the integration of chitin-binding proteins for enhanced antifungal activity

Amphotericin B (AMB) is a gold standard antifungal drug because of its broad-spectrum activity toward pathogenic yeasts and molds. Because of its low solubility in water and toxicity toward humans, several lipid-based formulations that either increase the aqueous solubility or decrease the side effects have been employed in practical use. In our previous research, we found that the combination of AMB with an artificial palmitoylated chitin-binding domain from Pteris ryukyuensis chitinase (LysM-Pal) resulted in synergistic antifungal action against Trichoderma viride. Herein, we prepared hybrid liposomal formulations by combining a commercially available AMB formulation and liposomes with different surface charges to explore key factors in the antifungal activity. The characterization of AMB-loaded liposomal formulations (AMB-LFs), including particle size distribution and zeta potential, showed that anionic and neutral AMB-LFs could stably encapsulate AMB. The combination of either anionic or neutral AMB-LFs with unmodified LysM decreased the minimum inhibitory concentration of AMB. The combination of neutral AMB-LF with LysM-Pal resulted in a further decrease in the MIC, up to 15-fold compared with that of the neutral AMB-LF alone. Our results demonstrate the potential utility of lipid-based liposomal formulations of AMB combined with lipid-modified proteinaceous binders to tackle fungal infections.

Enhancement of the Antifungal Activity of Chitinase by Palmitoylation and the Synergy of Palmitoylated Chitinase with Amphotericin B

Combinations of antifungal drugs can have synergistic antifungal activity, achieving high therapeutic efficacy while minimizing the side effects. Amphotericin B (AMB) has been used as a standard antifungal drug for fungal infections; however, because of its high toxicity, new strategies to minimize the required dose are desirable. Chitinases have recently received attention as alternative safe antifungal agents. Herein, we report the combination of palmitoylated chitinase domains with AMB to enhance the antifungal activity. The chitin-binding domain (LysM) from Pteris ryukyuensis chitinase was site-specifically palmitoylated by conjugation reaction catalyzed by microbial transglutaminase. The palmitoylated LysM (LysM-Pal) exhibited strong antifungal activity against Trichoderma viride, inhibiting the growth completely at a concentration of 2 μM. This antifungal effect of LysM-Pal was mainly due to the effect of anchoring of palmitic acid motif to the plasma membrane of fungi. A combination of AMB with LysM-Pal resulted in synergistic enhancement of the antifungal activity. Intriguingly, LysM-Pal exhibited higher level of antifungal activity enhancement than palmitoylated catalytic domain (CatD) and fusion of LysM and CatD. Addition of 0.5 μM LysM-Pal to AMB reduced the minimal inhibition concentration of AMB to 0.31 μM (2.5 μM without LysM-Pal). The possible mechanism of the synergistic effect of AMB and LysM-Pal is destabilization of the plasma membrane by anchoring of palmitic acid and ergosterol extraction by AMB and destabilization of the chitin layer by LysM binding. The combination of LysM-Pal with AMB can drastically reduce the dose of AMB and may be a useful strategy to treat fungal infections.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis treatment and follow-up of patients with localised colon cancer

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of localised colon cancer was published in 2020. It was decided by both the ESMO and the Japanese Society of Medical Oncology (JSMO) to convene a special virtual guidelines meeting in March 2021 to adapt the ESMO 2020 guidelines to take into account the ethnic differences associated with the treatment of localised colon cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with localised colon cancer representing the oncological societies of Japan (JSMO), China (CSCO), India (ISMPO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug availability and reimbursement situations in the different Asian countries.

Recombinant production of active microbial transglutaminase in E. coli by using self-cleavable zymogen with mutated propeptide

Microbial transglutaminase from Streptomyces mobaraensis (MTG) has been widely used in food industry and also in research and medical applications, since it can site-specifically modify proteins by the cross-linking reaction of glutamine residue and the primary amino group. The recombinant expression system of MTG in E. coli provides better accessibility for the researchers and thus can promote further utilization of MTG. Herein, we report production of active and soluble MTG in E. coli by using a chimeric protein of tobacco etch virus (TEV) protease and MTG zymogen. A chimera of TEV protease and MTG zymogen with native propeptide resulted in active MTG contaminated with cleaved propeptide due to the strong interaction between the propeptide and catalytic domain of MTG. Introduction of mutations of K9R and Y11A to the propeptide facilitated dissociation of the cleaved propeptide from the catalytic domain of MTG and active MTG without any contamination of the propeptide was obtained. The specific activity of the active MTG was 22.7 ± 2.6 U/mg. The successful expression and purification of active MTG by using the chimera protein of TEV protease and MTG zymogen with mutations in the propeptide can advance the use of MTG and the researches using MTG mediated cross-linking reactions.

JSCO-ESMO-ASCO-JSMO-TOS: international expert consensus recommendations for tumour-agnostic treatments in patients with solid tumours with microsatellite instability or NTRK fusions

A Japan Society of Clinical Oncology (JSCO)-hosted expert meeting was held in Japan on 27 October 2019, which comprised experts from the JSCO, the Japanese Society of Medical Oncology (JSMO), the European Society for Medical Oncology (ESMO), the American Society of Clinical Oncology (ASCO), and the Taiwan Oncology Society (TOS). The purpose of the meeting was to focus on what we have learnt from both microsatellite instability (MSI)/deficient mismatch repair (dMMR) biomarkers in predicting the efficacy of anti-programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) immunotherapy, and the neurotrophic tyrosine receptor kinase (NTRK) gene fusions in predicting the efficacy of inhibitors of the tropomyosin receptor kinase (TRK) proteins across a range of solid tumour types. The recent regulatory approvals of the anti-PD-1 antibody pembrolizumab and the TRK inhibitors larotrectinib and entrectinib, based on specific tumour biomarkers rather than specific tumour type, have heralded a paradigm shift in cancer treatment approaches. The purpose of the meeting was to develop international expert consensus recommendations on the use of such tumour-agnostic treatments in patients with solid tumours. The aim was to generate a reference document for clinical practice, for pharmaceutical companies in the design of clinical trials, for ethics committees in the approval of clinical trial protocols and for regulatory authorities in relation to drug approvals, with a particular emphasis on diagnostic testing and patient selection.

A randomized, open-label, controlled trial of monthly oral minodronate or semiannual subcutaneous injection of denosumab for bone loss by androgen deprivation in Asian men with prostate cancer: the PRevention of Osteopenia with Minodronate And DEnosumab (PROMADE) study

There is still a lack of evidence that minodronate or denosumab prevents bone loss due to androgen deprivation therapy (ADT) in non-Western patients. This study showed that both drugs significantly improved lumbar spine and total hip bone mineral density in Asian men with prostate cancer who received ADT.

INTRODUCTION

To evaluate whether monthly oral minodronate or semiannual subcutaneous injection of denosumab improves bone mineral density (BMD) in Asian men with prostate cancer (PCa) receiving ADT.

METHODS

A multicenter, open-label, randomized, controlled study including patients with hormone-sensitive PCa without bone metastasis receiving ADT was performed. Patients were randomized (1:1:1) to minodronate, denosumab, or no agent control groups. The primary end point was the mean percentage change in BMD at the lumbar spine at 12 months. Secondary end points were the mean percentage change in BMD at the femoral neck and total hip and changes in bone turnover markers. Statistical comparison was performed using analysis of covariance.

RESULTS

Of the 147 subjects enrolled in this study, 102 were randomly assigned into the minodronate (n = 36), denosumab (n = 36), and control (n = 30) groups. The percentage change in BMD at the lumbar spine was significantly improved in the minodronate (2.5%, p < 0.05) and denosumab groups (4.0%, p < 0.01) compared with that in the control group (- 0.1%). Denosumab increased BMD at the femoral neck and total hip at 12 months, whereas minodronate only increased BMD at the total hip compared with controls (all p < 0.05). The percentage change in bone turnover markers at 12 months was significantly lower in the minodronate and denosumab groups compared with that in the control group (both p < 0.01).

CONCLUSION

Minodronate or denosumab can be used for preventing bone loss related to ADT in Asian patients with PCa.

Nintedanib for the treatment of patients with refractory metastatic colorectal cancer (LUME-Colon 1): a phase III, international, randomized, placebo-controlled study

Background

Angiogenesis is critical to colorectal cancer (CRC) growth and metastasis. Phase I/II studies have demonstrated the efficacy of nintedanib, a triple angiokinase inhibitor, in patients with metastatic CRC. This global, randomized, phase III study investigated the efficacy and safety of nintedanib in patients with refractory CRC after failure of standard therapies.

Patients and methods

Eligible patients (Eastern Cooperative Oncology Group performance status 0–1, with histologically/cytologically confirmed metastatic/locally advanced CRC adenocarcinoma unamenable to surgery and/or radiotherapy) were randomized 1 : 1 to receive nintedanib (200 mg twice daily) or placebo (twice daily), until disease progression or undue toxicity. Patients were stratified by previous regorafenib, time from onset of metastatic disease to randomization, and region. Co-primary end points were overall survival (OS) and progression-free survival (PFS) by central review. Secondary end points included objective tumor response and disease control by central review.

Results

From October 2014 to January 2016, 768 patients were randomized; 765 were treated (nintedanib n = 384; placebo n = 381). Median follow-up was 13.4 months (interquartile range 11.1–15.7). OS was not improved [median OS 6.4 months with nintedanib versus 6.0 months with placebo; hazard ratio (HR), 1.01; 95% confidence interval (CI), 0.86–1.19; P = 0.8659]. There was a significant but modest increase in PFS with nintedanib versus placebo (median PFS 1.5 versus 1.4 months, respectively; HR 0.58; 95% CI 0.49–0.69; P < 0.0001). There were no complete or partial responses. Adverse events (AEs) occurred in 97% of 384 nintedanib-treated patients and 93% of 381 placebo-treated patients. The most frequent grade ≥3 AEs were liver-related AEs (nintedanib 16%; placebo 8%) and fatigue (nintedanib 9%; placebo 6%).

Conclusions

The study failed to meet both co-primary end points. Nintedanib did not improve OS and was associated with a significant but modest increase in PFS versus placebo. Nintedanib was well tolerated.

ClinicalTrials.gov number

NCT02149108 (LUME-Colon 1).

PRDM14 promotes malignant phenotype and correlates with poor prognosis in colorectal cancer

BACKGROUND

Emerging evidence suggests that stemness in cancer cells is a cause of drug resistance or metastasis and is an important therapeutic target. PR [positive regulatory domain I-binding factor 1 (PRDI-BF1) and retinoblastoma protein-interacting zinc finger gene (RIZ1)] domain containing 14 (PRDM14), that regulates pluripotency in primordial germ cell, has reported the overexpression and function of stemness in various malignancies, suggesting it as the possible therapeutic target. However, to our knowledge, there have been no reports on the expression and function of PRDM14 in colorectal cancer (CRC). Therefore, we investigated the expression and the role of PRDM14 in CRC.

METHODS

We performed immunohistochemistry evaluations and assessed PRDM14 expression on 414 primary CRC specimens. Colon cancer cell lines were subjected to functional and stemness assays in vitro and in vivo.

RESULTS

We found that PRDM14 positive staining exhibited heterogeneity in the CRC primary tumor, especially at the tumor invasion front. The aberrant expression of PRDM14 at the invasion front was associated with lymph node metastasis and disease stage in patients with CRC. Furthermore, the multivariate analysis revealed high PRDM14 expression as an independent prognostic factor in the patients with Stage III CRC. Overexpression of PRDM14 enhanced the invasive, drug-resistant and stem-like properties in colon cancer cells in vitro and tumorigenicity in vivo.

CONCLUSION

Our findings suggest that PRDM14 is involved in progression and chemoresistance of CRC, and is a potential prognostic biomarker and therapeutic target in the CRC patients.

Pan-Asian adapted ESMO consensus guidelines for the management of patients with metastatic colorectal cancer: a JSMO-ESMO initiative endorsed by CSCO, KACO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) consensus guidelines for the treatment of patients with metastatic colorectal cancer (mCRC) was published in 2016, identifying both a more strategic approach to the administration of the available systemic therapy choices, and a greater emphasis on the use of ablative techniques, including surgery. At the 2016 ESMO Asia Meeting, in December 2016, it was decided by both ESMO and the Japanese Society of Medical Oncology (JSMO) to convene a special guidelines meeting, endorsed by both ESMO and JSMO, immediately after the JSMO 2017 Annual Meeting. The aim was to adapt the ESMO consensus guidelines to take into account the ethnic differences relating to the toxicity as well as other aspects of certain systemic treatments in patients of Asian ethnicity. These guidelines represent the consensus opinions reached by experts in the treatment of patients with mCRC identified by the Presidents of the oncological societies of Japan (JSMO), China (Chinese Society of Clinical Oncology), Korea (Korean Association for Clinical Oncology), Malaysia (Malaysian Oncological Society), Singapore (Singapore Society of Oncology) and Taiwan (Taiwan Oncology Society). The voting was based on scientific evidence and was independent of both the current treatment practices and the drug availability and reimbursement situations in the individual participating Asian countries.

Phosphorylation of GATA4 serine 105 but not serine 261 is required for testosterone production in the male mouse

BACKGROUND

GATA4 is a transcription factor essential for male sex determination, testicular differentiation during fetal development, and male fertility in the adult. GATA4 exerts part of its function by regulating multiple genes in the steroidogenic enzyme pathway. In spite of these crucial roles, how the activity of this factor is regulated remains unclear.

OBJECTIVES

Studies in gonadal cell lines have shown that GATA4 is phosphorylated on at least two serine residues-serine 105 (S105) and serine 261 (S261)-and that this phosphorylation is important for GATA4 activity. The objective of the present study is to characterize the endogenous role of GATA4 S105 and S261 phosphorylation in the mouse testis.

MATERIALS AND METHODS

We examined both previously described GATA4 S105A mice and a novel GATA4 S261A knock-in mouse that we generated by CRISPR/Cas9 gene editing. The male phenotype of the mutants was characterized by assessing androgen-dependent organ weights, hormonal profiles, and expression of multiple testicular target genes using standard biochemical and molecular biology techniques.

RESULTS

The fecundity of crosses between GATA4 S105A mice was reduced but without a change in sex ratio. The weight of androgen-dependent organs was smaller when compared to wild-type controls. Plasma testosterone levels showed a 70% decrease in adult GATA4 S105A males. This decrease was associated with a reduction in Cyp11a1, Cyp17a1, and Hsd17b3 expression. GATA4 S261A mice were viable and testis morphology appeared normal. Testosterone production and steroidogenic enzyme expression were not altered in GATA4 S261A males.

DISCUSSION AND CONCLUSION

Our analysis showed that blocking GATA4 S105 phosphorylation is associated with decreased androgen production in males. In contrast, S261 phosphorylation by itself is dispensable for GATA4 function. These results confirm that endogenous GATA4 action is essential for normal steroid production in males and that this activity requires phosphorylation on at least one serine residue.