Evaluation of the accuracy of ChatGPT's responses to and references for clinical questions in physical therapy.

[Purpose] This study evaluated the accuracy of ChatGPT's responses to and references for five clinical questions in physical therapy based on the Physical Therapy Guidelines and assessed this language model's potential as a tool for supporting clinical decision-making in the rehabilitation field. [Participants and Methods] Five clinical questions from the "Stroke", "Musculoskeletal disorders", and "Internal disorders" sections of the Physical Therapy Guidelines, released by the Japanese Society of Physical Therapy, were presented to ChatGPT. ChatGPT was instructed to provide responses in Japanese accompanied by references such as PubMed IDs or digital object identifiers. The accuracy of the generated content and references was evaluated by two assessors with expertise in their respective sections by using a 4-point scale, and comments were provided for point deductions. The inter-rater agreement was evaluated using weighted kappa coefficients. [Results] ChatGPT demonstrated adequate accuracy in generating content for clinical questions in physical therapy. However, the accuracy of the references was poor, with a significant number of references being non-existent or misinterpreted. [Conclusion] ChatGPT has limitations in reference selection and reliability. While ChatGPT can offer accurate responses to clinical questions in physical therapy, it should be used with caution because it is not a completely reliable model.

Prospective analysis of the expression status of FGFR2 and HER2 in colorectal and gastric cancer populations: DS-Screen Study.

PURPOSE: Fibroblast growth factor receptor 2 (FGFR2) and human epidermal growth factor receptor 2 (HER2) proteins are both molecular targets for cancer therapy. The objective of this study was to evaluate the expression status of FGFR2 and HER2 in patients with gastric cancer (GC) or colorectal cancer (CRC). METHODS: Archived tumor tissue samples from patients with histologically-confirmed GC or CRC suitable for chemotherapy were analyzed for FGFR2 and HER2 expression using immunohistochemistry and fluorescence in situ hybridization (HER2 in CRC only). RESULTS: A total of 176 GC patients and 389 CRC patients were enrolled. Among patients with GC, 25.6% were FGFR2-positive and 26.1% were HER2-positive. Among patients with CRC, 2.9% were FGFR2-positive and 16.2% were HER2-positive. No clear relationship was found between FGFR2 and HER2 status in either GC or CRC. In GC, FGFR2 and HER2 statuses did not differ between different primary cancer locations, whereas there were some differences between histological types. Based on FGFR2- and/or HER2-positive status, 117 patients were identified as potentially suitable for inclusion in clinical trials of therapeutic agents targeting the relevant protein (GC = 45, CRC = 72; FGFR = 56, HER2 = 62), of whom 7 were eventually enrolled into such clinical trials. CONCLUSIONS: This study indicated the prevalence of FGFR2 and HER2 in GC and CRC in the Japanese population. The screening performed in this study could be useful for identifying eligible patients for future clinical trials of agents targeting these proteins. TRIAL REGISTRATION: Clinical trial registration Japic CTI No.: JapicCTI-163380.  https://www. CLINICALTRIALS: jp/cti-user/trial/ShowDirect.jsp?directLink=RNlzx1PPCuT.PrVNPxPRwA .

Impact of chronological age on efficacy and safety of fluoropyrimidine plus bevacizumab in older non-frail patients with metastatic colorectal cancer: a combined analysis of individual data from two phase II studies of patients aged >75 years.

OBJECTIVE: Many clinical trials for older patients with metastatic colorectal cancer have been conducted, and fluoropyrimidine and bevacizumab are standard treatments. However, the relationship between age and the efficacy and safety of this treatment is unclear in older metastatic colorectal cancer patients. METHODS: Individual data from two phase II studies on older (≥75 years), non-frail patients with metastatic colorectal cancer treated with uracil-tegafur/leucovorin or S-1 combined with bevacizumab were collected. Patient characteristics were evaluated with multiple regression analyses for survival outcomes, using the Cox proportional hazard model and linear regression analyses for the worst grade of adverse events. RESULTS: We enrolled 102 patients with a median age of 80 years (range, 75-88 years). Of the 70 patients who died, seven (10%) died of causes unrelated to disease or treatment. The study treatment was discontinued due to adverse events in 19 patients (18.6%), with 63% aged ≥85 years. The adverse event that most commonly resulted in treatment discontinuation was grade 2 fatigue (21%). Chronological age was not associated with progression-free survival (Hazard ratio, 1.03; P = 0.40) or overall survival (Hazard ratio, 1.02; P = 0.65). Age was weakly associated with non-hematologic adverse events (regression coefficient [R], 0.27; P = 0.007), especially fatigue (R, 0.23; P = 0.02) and nausea (R, 0.19; P = 0.06), but not with hematologic (R, 0.05; P = 0.43) or bevacizumab-related (R, -0.06; P = 0.56) adverse events. CONCLUSIONS: The efficacy of fluoropyrimidine plus bevacizumab was age-independent in patients with metastatic colorectal cancer aged ≥75 years, and attention should be paid to non-hematologic adverse events as age increases.

Cancer-related FGFR2 overexpression and gene amplification in Japanese patients with gastric cancer.

OBJECTIVE: Fibroblast growth factor receptor 2 (FGFR2) has been proposed as a novel druggable target in unresectable gastric cancer. FGFR2 alteration has been reported as associated with poor prognosis even in patients with gastric cancer who received systemic chemotherapy. This study aimed to evaluate the frequency of FGFR2 overexpression and gene amplification in clinical specimens from Japanese patients with recurrent or unresectable gastric cancer. METHODS: This observational study enrolled patients who were histologically or cytologically confirmed with unresectable HER2-negative or unknown gastric or gastroesophageal junctional adenocarcinoma treated with at least one previous chemotherapy. FGFR2 overexpression and gene amplification in the specimens were evaluated by immunohistochemical staining and fluorescence in situ hybridization methods, respectively. RESULTS: In a total of 173 eligible cases, FGFR2 immunohistochemistry score was evaluated as 0, 1, 2, 3 and 4 for 20, 80, 35, 28 and 10 cases, respectively. In 151 evaluable cases with FGFR2 immunohistochemistry scores of 1-4, FGFR2 copy number expressed as fluorescence in situ hybridization signals were detected as <4, ≥4 < 10 and ≥10 copies for 123, 16 and 12 cases, respectively. FGFR2 copy number showed an increasing tendency along with higher FGFR2 immunohistochemistry scores in the corresponding specimen. The response rate and time to treatment failure for first line chemotherapy did not have any obvious relationship to FGFR2 immunohistochemistry score and FGFR2 copy number. CONCLUSIONS: Although FGFR2 overexpression and gene amplification were shown in Japanese patients with unresectable gastric cancer, these alterations did not impact the effects of cytotoxic agents as first line chemotherapy.

Randomised phase II study of panitumumab plus irinotecan versus cetuximab plus irinotecan in patients with KRAS wild-type metastatic colorectal cancer refractory to fluoropyrimidine, irinotecan and oxaliplatin (WJOG 6510G).

BACKGROUND: Cetuximab has been shown to be clinically active when given in combination with irinotecan in patients with irinotecan-refractory metastatic colorectal cancer (mCRC). However, it has remained unclear whether panitumumab is effective when combined with irinotecan. We compared efficacies of both regimens in this randomised phase II study. PATIENTS AND METHODS: Patients with wild-type KRAS exon 2 mCRC previously treated with fluorouracil-, oxaliplatin- and irinotecan-based chemotherapies were randomised (1:1) to either panitumumab plus irinotecan (panitumumab arm) or cetuximab plus irinotecan (cetuximab arm). The primary end-point was progression-free survival (PFS). The planned sample size was 120, expecting a hazard ratio (HR) of 1.0 with non-inferiority margin of 1.3 (one-sided alpha error 0.2 and power 0.7). Major secondary end-points were overall survival (OS), response rate and safety. RESULTS: From December 2011 to September 2014, 121 patients were enrolled, and 61 and 59 patients were randomised to the panitumumab and cetuximab arms, respectively (1 patient excluded). Most patients (97%) had received prior chemotherapies containing bevacizumab. The median PFS was 5.42 months in the panitumumab arm and 4.27 months in the cetuximab arm (HR = 0.64, 95% confidence interval [CI] = 0.44-0.94, P < 0.001 for non-inferiority, P = 0.058 for superiority), and median OS was 14.85 and 11.53 months (HR = 0.66, 95% CI = 0.44-1.00, P = 0.050 for superiority), respectively. The incidence of grade 3 or 4 hypomagnesaemia was higher in the panitumumab arm than that in the cetuximab arm (17% vs. 7%). CONCLUSION: Panitumumab may be non-inferior to cetuximab in combination with irinotecan in survival of patients with irinotecan-refractory mCRC.

Randomized, Phase II Study of Trastuzumab Beyond Progression in Patients With HER2-Positive Advanced Gastric or Gastroesophageal Junction Cancer: WJOG7112G (T-ACT Study).

PURPOSE: This study evaluated the continuous use of trastuzumab beyond progression (TBP) in human epidermal growth factor receptor 2 (HER2)-positive advanced gastric or gastroesophageal junction (G/GEJ) cancer. PATIENTS AND METHODS: Patients with HER2-positive advanced G/GEJ cancer refractory to first-line chemotherapy with trastuzumab in combination with fluoropyrimidine and platinum were eligible. Patients were randomly assigned to the paclitaxel (80 mg/m2, days 1, 8, and 15, every 4 weeks) or paclitaxel with trastuzumab (PT; initially 8 mg/kg followed by 6 mg/kg, every 3 weeks) arms. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), response rate, and safety. Biomarkers such as HER2 expression status in tumor tissue after first-line treatment, HER2 amplification evaluated in serum cell-free DNA, and soluble HER2 levels were analyzed. RESULTS: Overall, 91 patients were allocated to the paclitaxel (n = 46) and PT (n = 45) arms. The median PFS in the paclitaxel and PT arms was 3.2 and 3.7 months, respectively (hazard ratio [HR], 0.91; 80% CI, 0.67 to 1.22; P = .33), and the median OS in both arms was 10 months (HR, 1.2; 95% CI, 0.75 to 2.0; P = .20). The overall response rates in the paclitaxel and PT arms were 32% and 33%, respectively (P = 1.00), and safety was comparable between the 2 arms. On exploratory analyses, HER2 positivity of tumor tissues was lost after first-line chemotherapy in 11 (69%) of 16 patients whose tumor tissues were available, and circulating HER2 DNA amplification was detected in 41 (60%) of 68 patients. However, no biomarkers associated with efficacy of TBP were found. CONCLUSION: The TBP strategy failed to improve PFS in patients with HER2-positive advanced G/GEJ cancer, and no beneficial biomarkers were found.

Phase II study of S-1 on alternate days plus bevacizumab in patients aged ≥ 75 years with metastatic colorectal cancer (J-SAVER).

BACKGROUND: Alternate-day administration of S-1 is thought to reduce toxicities. This phase II study evaluated S-1 on alternate days combined with bevacizumab as first-line treatment for elderly patients with metastatic colorectal cancer. PATIENTS AND METHODS: Eligible patients had histologically proven colorectal adenocarcinoma, measurable metastatic lesions, age ≥ 75 years, Eastern Cooperative Oncology Group performance status ≤ 1, no previous chemotherapy, and refused oxaliplatin- or irinotecan-containing regimens. Patients received 40 mg, 50 mg, or 60 mg (body surface area ≤ 1.25 m2, > 1.25 to ≤ 1.50 m2, or > 1.50 m2, respectively) of S-1 twice orally on Sunday, Monday, Wednesday, and Friday every week. Bevacizumab (7.5 mg/kg) was administered every 3 weeks. The primary endpoint was progression-free survival. RESULTS: Of 54 enrolled patients, 50 patients were evaluated for efficacy and 53 for safety. The median age was 79 years (range 75-88 years). The median progression-free survival was 8.1 months (95% confidence interval (CI) 6.7-9.5 months). The median overall survival was 23.1 months (95% CI 17.4-28.8 months). The response rate was 44% (95% CI 30.2-57.8%), and the disease control rate was 88% (95% CI 79.0-97.0%). Grade 3 or higher hematologic, non-hematologic, and bevacizumab-related adverse events occurred in 9%, 11%, and 25% of patients, respectively. The most common grade 3 and 4 treatment-related adverse events were hypertension (11%), nausea (6%), fatigue (6%), anemia (6%), and proteinuria (6%). Only 6 patients discontinued treatment due to adverse events. CONCLUSION: S-1 on alternate days combined with bevacizumab showed better tolerability and comparable survival compared with the results of similar studies.

Newly developed endoscopic detachable snare ligation therapy for colonic diverticular hemorrhage: a multicenter phase II trial (with videos).

BACKGROUND AND AIMS: We previously reported preliminary safety results for a new method, endoscopic detachable snare ligation (EDSL), for diverticular hemorrhage. This method does not need endoscope removal to attach a ligation device after detection of the bleeding site. The aim of the present study was to evaluate the efficacy and safety of EDSL in a larger patient population. METHODS: This prospective study was conducted in 12 institutions. Patients suspected of having diverticular hemorrhage without serious systemic disease were enrolled. The primary endpoint was early (within 30 days) recurrent bleeding rate in patients treated with EDSL. The secondary endpoints were overall early recurrent bleeding rate in patients with definite diverticular bleeding and adverse events in patients treated with EDSL. RESULTS: From June 2015 to March 2017, bleeding diverticula were detected in 123 of 205 enrolled patients (60%), of whom 101 (82%) were treated with EDSL. Most patients (20/22) in whom EDSL was not successful were treated with clipping. The early recurrent bleeding rate was 7.9% (95% confidence interval, 2.6%-13.2%; 8/101) in patients who could be treated with EDSL. The median total endoscopic and EDSL procedure time was 40 minutes (interquartile range, 15-71) and 4 minutes (interquartile range, 1-7), respectively. Two mild adverse events, colonic diverticulitis and temporary abdominal pain, were observed. CONCLUSION: EDSL was confirmed to be useful and safe for treatment of colonic diverticular hemorrhage. (Clinical trial registration number: UMIN 000001858.).

Reactive swelling of the regional lymph nodes in patients with stage II colorectal cancer as a prognostic factor.

The aim of this study was to examine the relationship between reactive swelling of regional lymph node (LN) and survival in colorectal carcinoma. We retrospectively studied 170 patients with surgically resected colorectal carcinoma histopathologically diagnosed as stage II (pStage II). These patients were classified into two groups:a) a "reactive LN swelling" group (clinically diagnosed as positive for LN metastasis, but pathologically negative) and b) a "no LN swelling" group. Survival analyses of the two groups showed that overall survival (OS) and disease-specific survival (DSS) were longer in the reactive LN swelling group than in the no LN swelling group in patients with total colorectal and right-sided colon cancer. Multivariate analyses revealed that reactive LN swelling was an independent prognostic factor in OS and DSS in patients with right-sided colon cancer. Reactive swelling of regional LN is regarded as an expression of local immune responses, which could explain the present results.

Uracil-Tegafur and Oral Leucovorin Combined With Bevacizumab in Elderly Patients (Aged ≥ 75 Years) With Metastatic Colorectal Cancer: A Multicenter, Phase II Trial (Joint Study of Bevacizumab, Oral Leucovorin, and Uracil-Tegafur in Elderly Patients [J-BLUE] Study).

BACKGROUND: We previously reported that uracil-tegafur with oral leucovorin (UFT/LV) treatment for elderly patients (aged ≥ 75 years) was well-tolerated in a phase II study. In the present study, the efficacy and safety of a modified (1-week shorter administration period) UFT/LV schedule combined with bevacizumab for a similar population are reported. PATIENTS AND METHODS: The present study was a single-arm, open-label, multicenter, cooperative group clinical trial. The key eligibility criteria included age ≥ 75 years, Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1, first-line chemotherapy, measurable lesions, and preserved organ function. Patients received UFT 300 mg/m(2)/d and LV 75 mg/d on days 1 to 21 and intravenous bevacizumab 5 mg/kg on days 1 and 15. Treatment was repeated every 28 days. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were the objective response rate (ORR), overall survival (OS), and safety. RESULTS: Of the 55 patients enrolled from 15 Japanese institutions, 52 eligible patients were evaluated. Their median age was 80 years (range, 75-87 years), and 73% had an ECOG performance status of 0. The median PFS was 8.2 months (95% confidence interval [CI], 6.2-10 months). The ORR was 40% (95% CI, 27%-55%). The median OS was 23 months (95% CI, 12-33 months). The most common grade 3 and 4 treatment-related adverse events were hypertension (12%), fatigue (8%), anemia (8%), nausea (6%), and diarrhea (6%). Treatment-related death occurred in 2 patients. CONCLUSION: UFT/LV (3 weeks of therapy and 1 week without) combined with biweekly bevacizumab is a tolerable and effective treatment option for elderly patients (aged ≥ 75 years) with metastatic colorectal cancer.

Phase I study of gemcitabine, cisplatin, and S-1 combination therapy for patients with untreated advanced biliary tract cancer.

BACKGROUND: To develop a triplet regimen containing gemcitabine, cisplatin, and S-1 (GPS), we assessed the recommended dose for patients with untreated advanced biliary tract cancer in this phase I study. METHODS: Dose-limiting toxicities (DLTs) were evaluated for the following two dose levels: gemcitabine (1000 mg/m(2) for level 1 and 1200 mg/m(2) for level 2 on day 1), cisplatin (30 mg/m(2) fixed dose on day 1), and S-1 (40-60 mg/day fixed dose twice a day for 7 days), every 2 weeks until progression. DLTs for each level were evaluated in six or more patients during the first two cycles. RESULTS: A total of 18 patients were enrolled and 16 patients were evaluated. DLTs at level 1 were observed in two of 10 patients. At level 2, a DLT was observed in one of six patients. The main grade 3 or 4 treatment-related adverse events were neutropenia and leukopenia, and a few non-hematological toxicities were observed. Among 14 patients with measurable lesions, the best response rate was 50%. CONCLUSIONS: GPS with a relative dose intensity corresponding to 90% of the standard gemcitabine plus cisplatin regimen could be administered safely, and showed preliminary antitumor activity. Survival benefits will be studied subsequently.

Activity of lower limb muscles during treadmill running at different velocities.

[Purpose] The present study aimed to determine changes in muscle activity while moving on a treadmill at various speeds. [Subjects] The activities of the left vastus lateralis, vastus medialis, hip adductors, lateral head of gastrocnemius, medial head gastrocnemius, soleus, and tibialis anterior of 10 healthy male university students were analyzed. [Methods] University students walked, jogged, and ran for 10 minutes each in random order, and then myogenic potentials were measured 10 minutes later for 30 seconds. The flexion angle of the lower limb upon initial contact, mid stance, and toe off were measured. [Results] The average walking, jogging, and running speeds were 3.6 ± 0.4, 6.7 ± 0.6, and 10.4 ± 1.3 km/h, respectively. The average electromyographic activities of the vastus medial, tibialis anterior, medial head of gastrocnemius, and lateral head of gastrocnemius significantly differed. All muscles were more active during jogging and running than walking. Only the soleus was more active during running than walking, and the activities of the hip adductors and vastus lateralis did not significantly differ. [Conclusion] Velocity is faster and the angles of the lower limbs and ground reaction force (GRF) are larger during running than walking. The vastus medialis and soleus worked more easily according to the angle of the knee joint, whereas the tibialis anterior worked more easily at faster velocities and the medial and lateral heads of the gastrocnemius worked more easily with an increased GRF.

Glasgow Prognostic Score predicts poor prognosis among advanced biliary tract cancer patients with good performance status.

Advanced cancer patients with good performance status (PS) sometimes show poor prognosis despite receiving some chemotherapies. We evaluated prognosis of chemo-naïve advanced biliary tract cancer (ABTC) patients with good PS by Glasgow Prognostic Score (GPS). Sixty-two patients with Eastern Cooperative Oncology Group PS 0 or 1 were retrospectively analyzed, using multivariate Cox regression. GPS was defined with serum levels of two parameters, albumin >3.5 g/dl and C-reactive protein <1.0 mg/dl (both as 0, either as 1, and neither as 2). PS 0 (n = 32) and 1 (n = 30) patients had similar survival (P = 0.98). The median overall survival (OS) was 17.0 months for GPS 0 (n = 19), 14.2 months for GPS 1 (n = 17), and 6.4 months for GPS 2 (n = 26). GPS 2 had significantly shorter OS than GPS 0 (P = 0.002) or 1 (P = 0.033). Multivariate analysis identified two independent prognostic factors: GPS (hazard ratio 0.60, 95 % confidence interval 0.40-0.90, P = 0.012) and liver metastasis (hazard ratio 0.43, 95 % CI 0.20-0.90, P = 0.026). GPS was useful for chemo-naïve ABTC patients with good PS.

Interaction of Muc4 and ErbB2 in a transgenic mouse model of gallbladder carcinoma: potential pathobiological implications.

The molecular mechanism of gallbladder carcinogenesis and cancer growth remains unknown. BK5.erbB2 transgenic mice in which erbB2 is overexpressed and activated in the biliary epithelia develop adenocarcinoma of the gallbladder at a high incidence. Although it has been reported that erbB2 plays an important role in tumorigenesis, little is known about the involvement of its ligand(s). The expression level of Muc4, a potential functional ligand for erbB2, and its interaction with erbB2 in the gallbladder of BK5.erbB2 mice were determined. By immunohistochemistry and in situ hybridization, both Muc4 mRNA and protein levels were strongly expressed in the cancerous epithelia of gallbladder from BK5.erbB2 mice. Also, in the hyperplastic (precancerous) epithelia, the protein levels were modestly expressed. Immunostaining with Muc4 (ASGP2) Ab overlapped with that with erbB2 Ab in the apical membranous components of the cancerous epithelia, indicating the co-localization of Muc4 and erbB2. Immunoprecipitation experiments revealed an interaction between Muc4 and erbB2 in the gallbladders. The interaction was associated with the hyperphosphorylation of erbB2, MAPK and Akt, and also with the overexpression of cyclooxygenase-2. However, in other organs that overexpressed erbB2 (trachea, esophagus and forestomach), Muc4 was expressed in only trace or modest amounts, and erbB2 was not hyperphosphorylated. Collectively, Muc4 is upregulated and interacts with erbB2 in gallbladders from BK5.erbB2 mice. It is likely that Muc4 plays an important role during gallbladder carcinogenesis and/or cancer growth by potentiating erbB2 signaling.

Autoimmune pancreatitis and biliary intraepithelial neoplasia of the common bile duct: a case with diagnostically challenging but pathogenetically significant association.

Autoimmune pancreatitis (AIP) (also called IgG4-related sclerosing pancreatitis (IgG4-SP)) and IgG4-related sclerosing cholangitis (IgG4-SC) are frequently associated with each other. It is generally believed that association of these diseases with pancreatobiliary malignancy is, however, rare. Here, we report on the case of a patient with AIP whose biliary cytology revealed severely atypical cells. Surgically resected specimens from this patient showed typical AIP with IgG4-SC, as well as a mildly elevated lesion in the common bile duct with varying degrees of cellular atypia. In addition, the atypical cells tested positive for the mucin-core protein, MUC5AC and p53 overexpression. These findings led us to diagnose the common bile duct lesion as biliary intraepithelial neoplasia (BilIN, mainly BilIN-1/2). Recently, associations between K-ras mutations and pancreatobiliary carcinoma have been reported in patients with AIP. This case, therefore, provides important new insight into the potential association of AIP and/or IgG4-SC with malignancy (or precursor lesions) of the pancreatobiliary system.

Facilitation of corticospinal excitability during motor imagery of wrist movement with visual or quantitative inspection of EMG activity.

The present study investigated facilitation of corticospinal excitability during motor imagery of wrist movement with visual or quantitative inspection of background electromyographic (EMG) activity. Ten healthy participants imagined wrist extension from a first-person perspective in response to a start cue. Transcranial magnetic stimulation was delivered to the motor cortex 2 sec. after the start cue. EMG signals were recorded from the extensor carpi radialis muscle. Trials with background EMG activity were discarded based on visual inspection. Both motor-evoked potential (MEP) and background EMG amplitudes increased during motor imagery. The amount of increase in MEP amplitude was positively correlated with the amount of increase in background EMG amplitude during motor imagery. The statistically significant increase in MEP amplitude during motor imagery disappeared when the effect of muscle activity was statistically eliminated or after trials with background EMG activity were discarded based on strict quantitative criteria. Facilitation of corticospinal excitability during motor imagery of wrist movement depends partially on muscle activity. Discarding background EMG activity during motor imagery based on visual inspection is not sufficient to equalize background EMG amplitude between resting and motor imagery. Discarding trials with background EMG activity through strict quantitative criteria is useful to equalize background EMG amplitude between at rest and during motor imagery.

Development of an all-in-one technology for glycan profiling targeting formalin-embedded tissue sections.

An ultra-sensitive method for glycan analysis targeting small tissue sections (1.5mm in diameter) is described as an application of a recently-established lectin microarray technology. The developed system achieved a high level of detection of a tissue section consisting of approximately 500 cells for differential profiling, where both N- and O-glycans attached to a pool of glycoproteins are subjected to multiplex analysis with 43 lectins. By using an optimized protocol for differential glycan analysis, sections of adenocarcinoma (n=28) and normal epithelia (n=12) of the colon were analyzed in an all-in-one manner. As a result, Wisteria floribunda agglutinin (WFA) was found to clearly differentiate cancerous from normal epithelia with P<0.0001. The obtained results correlated well with the subsequent histochemical study using biotinylated WFA. Thus, the developed technology proved to be valid for expanding the lectin microarray applications to tissue-based glycomics, and hence, should accelerate a discovery phase of glycan-related biomarkers.

Polylactosamine on glycoproteins influences basal levels of lymphocyte and macrophage activation.

beta1,3-N-acetylglucosaminyltransferase 2 (beta3GnT2) is a polylactosamine synthase that synthesizes a backbone structure of carbohydrate structures onto glycoproteins. Here we generated beta3GnT2-deficient (beta3GnT2(-/-)) mice and showed that polylactosamine on N-glycans was markedly reduced in their immunological tissues. In WT mice, polylactosamine was present on CD28 and CD19, both known immune costimulatory molecules. However, polylactosamine levels on these molecules were reduced in beta3GnT2(-/-) mice. beta3GnT2(-/-) T cells lacking polylactosamine were more sensitive to the induction of intracellular calcium flux on stimulation with anti-CD3epsilon/CD28 and proliferated more strongly than T cells from WT mice. beta3GnT2(-/-) B cells also showed hyperproliferation on BCR stimulation. Macrophages from beta3GnT2(-/-) mice had higher cell surface CD14 levels and enhanced responses to endotoxin. These results indicate that polylactosamine on N-glycans is a putative immune regulatory factor presumably suppressing excessive responses during immune reactions.

Molecular cloning and characterization of a novel human beta1,3-glucosyltransferase, which is localized at the endoplasmic reticulum and glucosylates O-linked fucosylglycan on thrombospondin type 1 repeat domain.

Protein O-linked fucosylation is an unusual glycosylation associated with many important biological functions such as Notch signaling. Two fucosylation pathways synthesizing O-fucosylglycans have been reported on cystein-knotted proteins, that is, on epidermal growth factor-like (EGF-like) domains and on thrombospondin Type 1 repeat (TSR) domains. We report here the molecular cloning and characterization of a novel beta1,3-glucosyltransferase (beta3Glc-T) that synthesizes a Glcbeta1,3Fucalpha- structure on the TSR domain. We found a novel glycosyltransferase gene with beta1,3-glycosyltransferase (beta3GT) motifs in databases. The recombinant enzyme expressed in human embryonic kidney 293T (HEK293T) cells exhibited glucosyltransferase activity toward fucose-alpha-para-nitrophenyl (Fucalpha-pNp). Thin-layer chromatography (TLC) analysis revealed that the product of the recombinant enzyme migrated to the same position as did the product of endogenous beta3Glc-T of Chinese hamster ovary (CHO) cells. The two products could be digested by beta-glucosidase from almond and by exo-1,3-beta-glucanase from Trichoderma sp. These results strongly suggested that the product has the structure of Glcbeta1-3Fuc. Therefore, we named this novel enzyme beta3Glc-T. Immunostaining revealed that FLAG-tagged beta3Glc-T is an enzyme residing in the endoplasmic reticulum (ER) via retention signal, "REEL," which is a KDEL-like sequence, at the C-terminus. The TSR domain expressed in Escherichia coli was first fucosylated by the recombinant protein O-fucosyltransferase 2 (POFUT2), after which it became an acceptor substrate for the recombinant beta3Glc-T, which could apparently transfer Glc to the fucosylated TSR domain. Our results suggest that a novel glycosyltransferase, beta3Glc-T, contributes to the elongation of O-fucosylglycan and that this occurs specifically on TSR domains.

A novel beta1,3-N-acetylglucosaminyltransferase (beta3Gn-T8), which synthesizes poly-N-acetyllactosamine, is dramatically upregulated in colon cancer.

A new member of the UDP-N-acetylglucosamine: beta-galactose beta1,3-N-acetylglucosaminyltransferase (beta3Gn-T) family having the beta3-glycosyltransferase motifs was identified using an in silico method. This novel beta3Gn-T was cloned from a human colon cancer cell line and named beta3Gn-T8 based on its position in a phylogenetic tree and enzymatic activity. Beta3Gn-T8 transfers GlcNAc to the non-reducing terminus of the Galbeta1-4GlcNAc of tetraantennary N-glycan in vitro. HCT15 cells transfected with beta3Gn-T8 cDNA showed an increase in reactivity to both LEA and PHA-L4 in a flow cytometric analysis. These results indicated that beta3Gn-T8 is involved in the biosynthesis of poly-N-acetyllactosamine chains on tetraantennary (beta1,6-branched) N-glycan. In most of the colorectal cancer tissues examined, the level of beta3Gn-T8 transcript was significantly higher than in normal tissue. Beta3Gn-T8 could be an enzyme involved in the synthesis of poly-N-acetyllactosamine on beta1-6 branched N-glycans in colon cancer.