Disruption of p-coumaroyl-CoA:monolignol transferases in rice drastically alters lignin composition.

Grasses are abundant feedstocks that can supply lignocellulosic biomass for production of cell-wall-derived chemicals. In grass cell walls, lignin is acylated with p-coumarate. These p-coumarate decorations arise from the incorporation of monolignol p-coumarate conjugates during lignification. A previous biochemical study identified a rice (Oryza sativa) BAHD acyltransferase (AT) with p-coumaroyl-CoA:monolignol transferase (PMT) activity in vitro. In this study, we determined that that enzyme, which we name OsPMT1 (also known as OsAT4), and the closely related OsPMT2 (OsAT3) harbor similar catalytic activity toward monolignols. We generated rice mutants deficient in either or both OsPMT1 and OsPMT2 by CRISPR/Cas9-mediated mutagenesis and subjected the mutants' cell walls to analysis using chemical and nuclear magnetic resonance methods. Our results demonstrated that OsPMT1 and OsPMT2 both function in lignin p-coumaroylation in the major vegetative tissues of rice. Notably, lignin-bound p-coumarate units were undetectable in the ospmt1 ospmt2-2 double-knockout mutant. Further, in-depth structural analysis of purified lignins from the ospmt1 ospmt2-2 mutant compared with control lignins from wild-type rice revealed stark changes in polymer structures, including alterations in syringyl/guaiacyl aromatic unit ratios and inter-monomeric linkage patterns, and increased molecular weights. Our results provide insights into lignin polymerization in grasses that will be useful for the optimization of bioengineering approaches for the effective use of biomass in biorefineries.

Gibberellin-biosynthetic ent-kaurene synthases in higher plants do not require their non-catalytic domains for the catalysis.

ent-Kaurene is a biosynthetic intermediate diterpene of phytohormone gibberellins, and is biosynthesized from geranylgeranyl diphosphate via ent-copalyl diphosphate (ent-CDP). The successive cyclization is catalyzed by two distinct diterpene synthases, ent-CDP synthase (ent-CPS) and ent-kaurene synthase (KS). Homologs of these diterpene synthase genes have been reported to be involved in the biosynthesis of specialized-metabolic diterpenoids for defense in several plant species, including rice (Oryza sativa). These diterpene synthases consist of three domains, αßγ domains. Active sites of ent-CPS exist at the interface of ß and γ domain, while those of KS are located within the α domain. We herein carried out domain-deletion experiments using several KSs and KS like enzymes (KSLs) to obtain insights into the roles of domains other than active-site domains. As previously reported in taxadiene synthase, deletion of γ or ßγ domains drastically decreased activities of specialized-metabolic OsKSL5, OsKSL8, OsKSL7 and OsKSL10 in O. sativa. However, unexpectedly, only α domains of several gibberellin-biosynthetic KSs, including OsKS1 in O. sativa, AtKS in Arabidopsis thaliana, TaKS in wheat (Triticum aestivum) and BdKS1 in Brachypodium distachyon, retained their original functions. Additionally, the specialized-metabolic OsKSL4, which is closely related to OsKS1, also functioned without its ßγ domains. Domain-swapping experiments showed that replacing ßγ domains in OsKSL7 with those from other KS/KSLs retained the OsKSL7 activity. Moreover, deletion of ßγ domains of bifunctional PpCPS/KS in moss (Physcomitrella patens) drastically impaired its KS-related activity. Thus, we demonstrate that monofunctional gibberellin-biosynthetic KSs are the unique diterpene synthases that retain their functions without ßγ domains.

Lignocellulose molecular assembly and deconstruction properties of lignin-altered rice mutants.

Bioengineering approaches to modify lignin content and structure in plant cell walls have shown promise for facilitating biochemical conversions of lignocellulosic biomass into valuable chemicals. Despite numerous research efforts, however, the effect of altered lignin chemistry on the supramolecular assembly of lignocellulose and consequently its deconstruction in lignin-modified transgenic and mutant plants is not fully understood. In this study, we aimed to close this gap by analyzing lignin-modified rice (Oryza sativa L.) mutants deficient in 5-HYDROXYCONIFERALDEHYDE O-METHYLTRANSFERASE (CAldOMT) and CINNAMYL ALCOHOL DEHYDROGENASE (CAD). A set of rice mutants harboring knockout mutations in either or both OsCAldOMT1 and OsCAD2 was generated in part by genome editing and subjected to comparative cell wall chemical and supramolecular structure analyses. In line with the proposed functions of CAldOMT and CAD in grass lignin biosynthesis, OsCAldOMT1-deficient mutant lines produced altered lignins depleted of syringyl and tricin units and incorporating noncanonical 5-hydroxyguaiacyl units, whereas OsCAD2-deficient mutant lines produced lignins incorporating noncanonical hydroxycinnamaldehyde-derived units. All tested OsCAldOMT1- and OsCAD2-deficient mutants, especially OsCAldOMT1-deficient lines, displayed enhanced cell wall saccharification efficiency. Solid-state nuclear magnetic resonance (NMR) and X-ray diffraction analyses of rice cell walls revealed that both OsCAldOMT1- and OsCAD2 deficiencies contributed to the disruptions of the cellulose crystalline network. Further, OsCAldOMT1 deficiency contributed to the increase of the cellulose molecular mobility more prominently than OsCAD2 deficiency, resulting in apparently more loosened lignocellulose molecular assembly. Such alterations in cell wall chemical and supramolecular structures may in part account for the variations of saccharification performance of the OsCAldOMT1- and OsCAD2-deficient rice mutants.

Deficiency in flavonoid biosynthesis genes CHS, CHI, and CHIL alters rice flavonoid and lignin profiles.

Lignin is a complex phenylpropanoid polymer deposited in the secondary cell walls of vascular plants. Unlike most gymnosperm and eudicot lignins that are generated via the polymerization of monolignols, grass lignins additionally incorporate the flavonoid tricin as a natural lignin monomer. The biosynthesis and functions of tricin-integrated lignin (tricin-lignin) in grass cell walls and its effects on the utility of grass biomass remain largely unknown. We herein report a comparative analysis of rice (Oryza sativa) mutants deficient in the early flavonoid biosynthetic genes encoding CHALCONE SYNTHASE (CHS), CHALCONE ISOMERASE (CHI), and CHI-LIKE (CHIL), with an emphasis on the analyses of disrupted tricin-lignin formation and the concurrent changes in lignin profiles and cell wall digestibility. All examined CHS-, CHI-, and CHIL-deficient rice mutants were largely depleted of extractable flavones, including tricin, and nearly devoid of tricin-lignin in the cell walls, supporting the crucial roles of CHS and CHI as committed enzymes and CHIL as a noncatalytic enhancer in the conserved biosynthetic pathway leading to flavone and tricin-lignin formation. In-depth cell wall structural analyses further indicated that lignin content and composition, including the monolignol-derived units, were differentially altered in the mutants. However, regardless of the extent of the lignin alterations, cell wall saccharification efficiencies of all tested rice mutants were similar to that of the wild-type controls. Together with earlier studies on other tricin-depleted grass mutant and transgenic plants, our results reflect the complexity in the metabolic consequences of tricin pathway perturbations and the relationships between lignin profiles and cell wall properties.

[Two Cases of Therapy-Related Myeloid Neoplasms after Docetaxel with Cyclophosphamide Therapy for Breast Cancer].

Docetaxel with cyclophosphamide(TC)is used as a perioperative chemotherapy. Therapy-related myeloid neoplasms(t- MN)are a rare adverse event of TC therapy. We report 2 cases of t-MN after TC therapy for breast cancer. Case 1 involved a 72-year-old woman who received 4 courses of TC therapy and radiation therapy after surgery. Two years and eight months after surgery, she presented with night sweats, coughing, headaches, and a low-grade fever. Laboratory examination revealed leukocytosis, and a bone marrow aspiration biopsy confirmed acute myelogenous leukemia with myeloid morphology- related changes and secondary acute myelogenous leukemia. Case 2 involved a 71-year-old woman who received 4 courses of TC therapy and radiation therapy after surgery. Three years and six months after surgery, ultrasonography detected right cervical lymphadenopathy. Resection of the right cervical lymph nodes and bone marrow aspiration biopsy confirmed mixed-phenotype acute leukemia(MPAL). Both patients are currently being treated.

Febrile neutropenia and role of prophylactic granulocyte colony-stimulating factor in docetaxel and cyclophosphamide chemotherapy for breast cancer.

PURPOSE: Febrile neutropenia (FN) incidence during docetaxel and cyclophosphamide (TC) chemotherapy, known as a high-risk regimen, differs among countries. The role of prophylactic granulocyte colony-stimulating factor (G-CSF) in FN is unclear. This study aimed to investigate FN frequency and relative dose intensity (RDI) of TC chemotherapy in patients with breast cancer and identify the correct population requiring prophylactic G-CSF. METHODS: In total, 205 patients with breast cancer were scheduled for TC chemotherapy (docetaxel/cyclophosphamide 75/600 mg/m2, every 3 weeks, 4 cycles) as adjuvant chemotherapy. Trastuzumab (8 mg/kg; continued with 6 mg/kg) was administrated intravenously for human epidermal growth factor receptor 2 (HER2)-positive cancer. Fifty-five patients received primary prophylactic measures (G-CSF: 20 and antibiotics: 35). We investigated the frequency of FN and hospitalization, RDI, and the factors related to FN, adverse events, hospitalization, and RDI. RESULTS: FN occurred in 70 patients (35.7%). FN incidence was noted in 41.1% without any prophylactic measures and in 5.0% with prophylactic G-CSF. In multivariate analysis, the independent risk factors of FN were older age (≥ 60 years, P = 0.017) and without primary prophylactic G-CSF (P = 0.011). Eleven patients (5.6%) were hospitalized of which 8 (72.7%) were elderly. The median RDIs of docetaxel and cyclophosphamide were 96.7% and 99.7%, respectively. CONCLUSION: FN frequency during TC chemotherapy was high, and primary prophylactic G-CSF reduced FN incidence. Primary prophylactic G-CSF is an effective therapy for preventing FN during TC chemotherapy. However, prophylactic G-CSF should be considered for elderly patients based on the low hospitalization rate and the high RDI.

Developing Heritable Mutations in Arabidopsis thaliana Using a Modified CRISPR/Cas9 Toolkit Comprising PAM-Altered Cas9 Variants and gRNAs.

Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9), comprising an RNA-guided DNA endonuclease and a programmable guide RNA (gRNA), is currently recognized to be a powerful genome-editing tool and is widely used in biological science. Despite the usefulness of the system, a protospacer-adjacent motif (PAM) immediately downstream of the target sequence needs to be taken into account in the design of the gRNA, a requirement which limits the flexibility of the CRISPR-based genome-editing system. To overcome this limitation, a Cas9 isolated from Streptococcus pyogenes, namely SpCas9, engineered to develop several variants of Cas9 nuclease, has been generated. SpCas9 recognizes the NGG sequence as the PAM, whereas its variants are capable of interacting with different PAMs. Despite the potential advantage of the Cas9 variants, their functionalities have not previously been tested in the widely used model plant, Arabidopsis thaliana. Here, we developed a plant-specific vector series harboring SpCas9-VQR (NGAN or NGNG) or SpCas9-EQR (NGAG) and evaluated their functionalities. These modified Cas9 nucleases efficiently introduced mutations into the CLV3 and AS1 target genes using gRNAs that were compatible with atypical PAMs. Furthermore, the generated mutations were passed on to their offspring. This study illustrated the usefulness of the SpCas9 variants because the ability to generate heritable mutations will be of great benefit in molecular genetic analyses. A greater number of potential SpCas9-variant-recognition sites in these genes are predicted, compared with those of conventional SpCas9. These results demonstrated the usefulness of the SpCas9 variants for genome editing in the field of plant science research.

Identification of Axillary Lymph Node Metastasis in Patients With Breast Cancer Using Dual-Phase FDG PET/CT.

OBJECTIVE. The aim of this study was to assess the diagnostic performance of dual-phase 18F-FDG PET/CT in detecting axillary lymph node metastasis in patients with breast cancer. MATERIALS AND METHODS. A total of 826 patients with breast cancer were retrospectively evaluated. PET/CT scans were performed 1 hour and 2 hours after FDG administration before treatment. The maximum standardized uptake value (SUVmax) in the axillary lymph node at both time points (hereafter referred to as SUVmax1 and SUVmax2, respectively) and the retention index (RI) were calculated. RESULTS. Axillary lymph node metastasis was detected in 285 of 826 patients (34.5%). The median axillary SUVmax1, SUVmax2, and RI in patients with nodal metastasis were higher than those in patients without metastasis (1.5 vs 0.6, 1.6 vs 0.5, and 7.7 vs -3.7, respectively; all p < 0.001). The diagnostic accuracy of axillary SUVmax1 and SUVmax2 was equivalent, and the sensitivity and specificity of SUVmax1 were 74.7% and 83.4%, respectively. Although the performance of the axillary RI was inferior to that of SUVmax1 and SUVmax2, both the SUVmax and the RI were independent predictors of nodal metastasis, and a positive RI suggested axillary lymph node involvement when the SUVmax1 was significantly high. Of 533 patients with category T1-2 breast cancer without lymph node swelling, 101 (19.0%) had pathologic lymph node involvement; the negative predictive value of axillary SUVmax1 was 86.8%. CONCLUSION. Delayed phase imaging identified axillary lymph node metastasis as accurately as standard PET/CT. A high negative predictive value of PET/CT for the detection of nodal metastasis is helpful to avoid surgical axillary assessment in patients with category T1-2 breast cancer without lymph node swelling.

[A Case of Primary Small Cell Carcinoma in the Breast with Neoadjuvant Chemotherapy That Were Difficult to Select Chemotherapy].

Primary small cell carcinoma in the breast is a rare and aggressive tumor, and a standard treatment strategy has not been established. Herein, we report a 35-year-old woman with primary small cell carcinoma in the breast. She had an 8 cm diameter tumor in the right breast. She was diagnosed with small cell carcinoma(cT3N1M0, cStage ⅢA)in the right breast, and neoadjuvant chemotherapy was planned. She received a combination chemotherapy of cisplatin(CDDP)and etoposide(VP- 16)based on the regimen for pulmonary small cell carcinoma; however, the disease showed progression. Therefore, 5-FU plus epirubicin plus cyclophosphamide(FEC)and weekly paclitaxel(PTX)chemotherapy based on a regimen for breast cancer were administered, and the tumor was partially reduced in size. Modified radical mastectomy followed by radiotherapy and hormonal therapy was performed. Ten months after the surgery, multiple liver and bone metastases occurred, and the patient died the following month. Further studies in other such patients are needed.

Fossils know it best: Using a new set of fossil calibrations to improve the temporal phylogenetic framework of murid rodents (Rodentia: Muridae).

Murid rodents (Rodentia: Muridae) represent the most diverse and abundant mammalian family. In this study, we provide a refined set of fossil calibrations which is used to reconstruct a dated phylogeny of the family using a multilocus dataset (six nuclear and nine mitochondrial gene fragments) encompassing 161 species representing 82 murid genera from four extant subfamilies (Deomyinae, Gerbillinae, Lophiomyinae and Murinae). In comparison with previous studies on murid or muroid rodents, our work stands out for the implementation of nine robust fossil constraints within the Muridae thanks to a thorough review of the fossil record. Before being assigned to specific nodes of the phylogeny, all potential fossil constraints were carefully assessed; they were also subjected to several cross-validation analyses. The resulting phylogeny is consistent with previous phylogenetic studies on murids, and recovers the monophyly of all sampled murid subfamilies and tribes. Based on nine controlled fossil calibrations, our inferred temporal timeframe indicates that the murid family likely originated in the course of the Early Miocene, 22.0-17.0 million years ago (Ma), and that most major lineages (i.e. tribes) started diversifying ca. 10 Ma. Historical biogeography analyses support the tropical origin for the family, with an initial internal split (vicariance event) between Afrotropical and Oriental (Indomalaya and Philippines) lineages. During the course of their diversification, the biogeographic pattern of murids is marked by several dispersal events toward the Australasian and the Palearctic regions. The Afrotropical region was also secondarily colonized at least three times from the Indomalaya, indicating that the latter region has acted as a major centre of diversification for the family.

Clozapine-Induced Acute Hyperglycemia Is Accompanied with Elevated Serum Concentrations of Adrenaline and Glucagon in Rats.

Clozapine, an atypical antipsychotic agent, has been reported to cause acute hyperglycemia. However, the mechanism of clozapine-induced rapidly developing hyperglycemia is not well elucidated. To clarify the mechanism underlying clozapine-induced acute hyperglycemia, we investigated the effects of single intravenous administration of clozapine on the serum concentrations of glucose and several endogenous substances in rats. Male Wistar rats received an intravenous injection of saline (control) or clozapine 2.5, 5, 10 mg/kg. Blood samples were obtained periodically after clozapine administration to determine the serum concentrations of glucose, adrenaline, glucagon, insulin, corticosterone, and clozapine. The serum concentrations of glucose, adrenaline, and glucagon increased dose-dependently after the administration of clozapine at 2.5-10 mg/kg, and reached maxima at 5 mg/kg of clozapine. The serum concentration of corticosterone increased after the administration of clozapine, but no significant variation was observed with the dosage of clozapine. The concentration of serum insulin increased in a dose-dependent manner after clozapine administration. In conclusion, a single administration of clozapine increased the serum concentration of glucose in rats, and adrenaline and/or glucagon would be associated with clozapine-induced acute hyperglycemia.

[A Case of Small Bowel Cancer Treated with Laparoscopic Surgery].

We report a case of small intestinal adenocarcinoma treated with laparoscopic surgery. A 70-year-old woman had abdominal pain and epigastralgia. There were no abnormal findings on upper and lower endoscopy. The symptoms continued for 4 months after endoscopy, so she presented to our hospital. After CT examination, small bowel cancer with ileus was suspected. An ileus tube was inserted to relieve the bowel pressure and she was diagnosed with ileum cancer by enteroscopy. Laparoscopic surgery was performed and the pathological stage was determined as pStage Ⅲa. She was treated with oral chemotherapy (UFT plus LV) and had no recurrence 6 months after surgery.

[Usefulness of Metallic Stent for Left-Sided Obstructive Colon Cancer].

The aim of this study was to compare the efficacy of self-expandable metallic stent (SEMS) and transanal tube as preoperative treatments for left-sided obstructive colon cancer. Forty-three patients (the SEMS group: 28 cases, the tube group: 15 cases) were included in this study. Clinicopathological data (age, sex, tumor location, depth, histological type, stage) were comparable between the 2 groups. In addition, there was no difference in intestinal decompression rate between the SEMS group and the tube group (technical success rate: 100% vs 86.7%, clinical success rate: 92.8% vs 73.3%, complication rate: 7.1% vs 0%). A significantly higher number of patients in the SEMS group underwent laparoscopic surgery because of difference of historical background. However, no significant difference was observed between the 2 groups in postoperative outcome(complication rate, hospital stay duration). SEMS insertion had several benefits compared to transanal tube placement, such as the resumption of oral intake because of rapid resolution of obstruction and easier management because SEMSs do not require washing. SEMS insertion could be a safe and effective bridge to subsequent surgery in patients with left-sided obstructive colon cancer.

[A Case of Radical Resection of Rectal Cancer with Multiple Liver and Lung Metastases after Preoperative Chemotherapy].

We report a case of radical resection of rectal cancer with multiple liver and lung metastases after preoperative chemotherapy. A 54-year-old woman presented with abdominal pain and loss of body weight due to rectal cancer with multiple liver and lung metastases. Therefore, the patient received 14 courses of bevacizumab+mFOLFOX6, and 7 courses of panitumumab+FOLFIRI. After the chemotherapy, the size of the distant metastases reduced by 62% on computed tomography, according to RECIST. Due to the reduction in size, a conversion surgery was attempted. First, an abdominal operation with laparoscopy was performed, and 2 months later an operation to resect the lung metastases via thoracoscopy was performed. Currently, 3 months after surgery, the patient is alive, without recurrence.

[A Case of Locally Advanced Rectal Cancer Successfully Treated by Conversion Surgery after Multidisciplinary Treatment].

A 70-year-old woman who complained of abdominal pain and a prolapsed tumor from the anus was diagnosed with an intestinal obstruction resulting from anal canal cancer. Computed tomography (CT) and magnetic resonance imaging revealed a huge tumor (11×5×12 cm) invading the vagina and levator ani muscle. Enlarged inguinal lymph nodes on both sides indicated metastasis. The clinical stage was T4b (vagina, levator ani muscle, and pudenda) N0H0M1a (LYM), stage IV (Japanese Classification of Colorectal Carcinoma: 8th edition). As curative resection was not possible, a transvers colostomy was performed to relieve the intestinal obstruction. This was followed by chemoradiotherapy (45 Gy/1.8 Gy×25; TS-1, 80 mg/body for 2 weeks and a 1-week interval, for 2 courses) and up to 10 courses of Bev+mFOLFOX6 continuously. After this regimen, there was a remarkable reduction in tumor size. Positron emission tomography-CT revealed no FDG uptake in the primary rectal site or inguinal lymph nodes, but a maximum standardized uptake value (SUVmax) of 6.3 was detected in the vagina. Six weeks after chemotherapy, the patient underwent a pelvic exenteration including resection of the vagina, bladder, and pudenda. The pathological stage was yp T4b (vagina) N0H0M0, stageⅡ. Curative resection was performed, and the patient had a Grade 2 pathological response after chemoradiotherapy.

Essential residues in diterpene synthases for biosynthesis of oryzalexins A-F in rice phytoalexin.

Cultivated rice (Oryza sativa) produces a variety of diterpenoid-type phytoalexins. Diterpene synthase genes that are responsible for the biosynthesis of momilactones, phytocassanes, and oryzalexins have been identified in O. sativa cv. Nipponbare. OsKSL10 (Os12t0491800 in RAP and LOC_Os12g30824 in MSU) was previously identified as an enzyme catalyzing the conversion of ent-copalyl diphosphate to ent-sandaracopimaradiene for the production of oryzalexins A to F. Our previous study on Oryza rufipogon, a wild progenitor of Asian cultivated rice, showed that both OrKSL10 and OrKSL10ind from O. rufipogon accessions W1943 and W0106, respectively, closely related to the japonica and indica subspecies, converted ent-copalyl diphosphate to ent-miltiradiene. Thus, the functional conversion of ent-miltiradiene synthase into ent-sandaracopimaradiene synthase is implied to have occurred through natural amino acid mutations, the details of which have not been elucidated. In this study, we show that introduction of A654G substitution into OrKSL10 significantly alters its function into more closely resembling that of OsKSL10. Moreover, double substitution V546I/A654G almost completely converts the function of OrKSL10 into that of OsKSL10. On the other hand, the reversed substitution I546V/G654A was insufficient to convert the function of OsKSL10 into OrKSL10, indicating the introduction of additional substitution S522I is required for the functionality of OsKSL10. Lastly, point mutations at the 654A residue in OrKSL10 suggest that hydrophobic side chains at this position have a negative influence on the production of ent-sandaracopimaradiene.

Persistent weekly paclitaxel-induced peripheral neuropathy in early breast cancer patients enrolled in a randomized trial of cryotherapy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious side effect of weekly paclitaxel-based chemotherapy for breast cancer, that can persist for years. Cryotherapy therapy is effective for preventing early CIPN, but its protective effect on persistent CIPN is uncertain. This is a cross-sectional study conducted as an ancillary analysis of a randomized trial investigating the preventive effect of cryotherapy on CIPN in breast cancer patients receiving weekly paclitaxel-based chemotherapy (UMIN000034966). Eligible patients were evaluated for CIPN at more than a year after completion of the chemotherapy (persistent CIPN). CIPN was defined as a 6 or more points reduction from baseline in the Functional Assessment of Cancer Therapy-Neurotoxicity (FACT-NTX) score. The incidence of early and persistent CIPN was compared between cryotherapy and control groups. Thirty-eight patients were examined for both early and persistent CIPN. The median time from completion of the weekly paclitaxel-based chemotherapy to the questionnaire for persistent CIPN was 2.3 (1.3-3.1) years. In all 38 patients, persistent CIPN was demonstrated in 10 (26.3%), respectively. There was a numerical, however not significant, reduction in the incidence of persistent CIPN (15.8% vs 36.8%, P = .1) in the cryotherapy group compared with the control group, respectively. In multivariate logistic regression analysis, age ≥ 65 was a substantial risk factor for persistent CIPN (HR: 14.7, 95%CI: 1.7-130.7, P = .01). In breast cancer patients receiving adjuvant weekly paclitaxel-based chemotherapy, cryotherapy resulted in a numerical, however not significant, reduction in the incidence of persistent CIPN and age>=65 was a risk factor for persistent CIPN.

18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Predicts Tumor Immune Microenvironment Function in Early Triple-negative Breast Cancer.

BACKGROUND/AIM: The maximum standardized uptake value (SUVmax) obtained using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is presumed to indicate tumor and active immune cells in the tumor immune microenvironment (TIME) based on their glycolysis activity. Therefore, this study investigated whether the metabolic parameter SUVmax could provide information regarding TIME in triple-negative breast cancer (TNBC) patients. PATIENTS AND METHODS: Fifty-four patients with TNBC underwent FDG PET/CT before neoadjuvant chemotherapy. Pretreatment biopsy specimens were pathologically evaluated. Expression statuses of CD8, forkhead box P3 (FOXP3), programmed cell death-1 (PD-1), and programmed cell death-ligand 1 (PD-L1) were assessed by immunohistochemistry. The relationships between immunological factors, including the tumor-infiltrating lymphocyte (TIL) grade and SUVmax or pathological complete response (pCR), were investigated. RESULTS: CD8, FOXP3, PD-1, and PD-L1 were high in 15 (27.8%), 39 (72.2%), 18 (33.3%), and 26 (48.2%) patients, respectively. SUVmax was significantly correlated with tumor size, Ki-67 labeling index, and CD8/FOXP3 ratio. Multiple linear regression analysis indicated that tumor size and the CD8/FOXP3 ratio predicted SUVmax. Seventeen patients (31.5%) achieved a pCR; TILs, the CD8/FOXP3 ratio, PD-1, and PD-L1 were significantly correlated with pCR rate. Multivariate analysis indicated that the CD8/FOXP3 ratio was the only independent predictive factor for pCR. CONCLUSION: SUVmax could provide metabolic information regarding TIME for TNBC patients and might be beneficial for formulating a treatment strategy and predicting pCR after neoadjuvant chemotherapy.

Impact of oral hygiene on febrile neutropenia during breast cancer chemotherapy.

PURPOSE: Oral hygiene is crucial in the management of oral and febrile complications during chemotherapy for cancer. This study aimed to investigate the impact of oral hygiene on the incidence of febrile neutropenia (FN) throughout the course of chemotherapy for breast cancer. METHODS: A total of 137 patients with breast cancer who underwent four cycles of adjuvant chemotherapy with docetaxel and cyclophosphamide (TC) combination therapy or docetaxel alone were assessed for oral hygiene by quantifying the number of oral bacteria they harbored. These patients received professional oral health care (POHC). Eighteen patients underwent primary prophylaxis with granulocyte colony-stimulating factors. The relationship between oral bacteria count and FN incidence was retrospectively assessed. RESULTS: The FN incidence rate was 47.4% throughout all treatment cycles (32.8%, 13.5%, 14.3%, and 14.4% in cycles 1, 2, 3, and 4, respectively). The oral bacteria count decreased with each treatment cycle (cycle 1: 9.10 × 106 colony-forming units (CFU)/mL, cycle 2: 5.89 × 106 CFU/mL, cycle 3: 4.61 × 106 CFU/mL, cycle 4: 5.85 × 106 CFU/mL, P = 0.004). Among 281 treatment cycles, FN occurred in 63 (22.4%). In the treatment cycle-based analysis, high oral bacteria count was an independent risk factor for FN. CONCLUSION: FN incidence decreased with each treatment cycle and was associated with changes in oral bacteria counts. The oral bacterial count was one of risk factors for FN development in breast cancer.

Coordinated regulation of the entry and exit steps of aromatic amino acid biosynthesis supports the dual lignin pathway in grasses.

Vascular plants direct large amounts of carbon to produce the aromatic amino acid phenylalanine to support the production of lignin and other phenylpropanoids. Uniquely, grasses, which include many major crops, can synthesize lignin and phenylpropanoids from both phenylalanine and tyrosine. However, how grasses regulate aromatic amino acid biosynthesis to feed this dual lignin pathway is unknown. Here we show, by stable-isotope labeling, that grasses produce tyrosine >10-times faster than Arabidopsis without compromising phenylalanine biosynthesis. Detailed in vitro enzyme characterization and combinatorial in planta expression uncovered that coordinated expression of specific enzyme isoforms at the entry and exit steps of the aromatic amino acid pathway enables grasses to maintain high production of both tyrosine and phenylalanine, the precursors of the dual lignin pathway. These findings highlight the complex regulation of plant aromatic amino acid biosynthesis and provide novel genetic tools to engineer the interface of primary and specialized metabolism in plants.