Integrin-interleukin-4 mechanotransduction pathways in human chondrocytes

INTRODUCTION Low intensity ultrasound (LIUS) is a special type of sonic pressure that can generate radiation forces, shear stresses and cavitation MATERIALS AND METHODS C-28/I2 cells (human chondrocyte cell line) were cultured in monolayer and treated with LIUS at an intensity of 200 mW/cm 2 using Noblelife TM (Duplogen Inc., Suwon, Korea). The role of stretchactivated channels (SAC) and integrins was first examined in mediating the LIUS effects on the expression of type II collagen and aggrecan by RT-PCR and Western blot analysis. Inhibitors for SACs (gadolinium) and integrins (GRGDSP peptide or anti-integrin α1 antibody) were used to confirm their specificity. The involvement of three MPAKs signal pathways in the LIUS-mediated phenotypic changes of chondrocytes and its mechanotrnsduction pathways was also investigated using the phospho-specific antibodies. Similar approaches are currently undergoing using rabbit primary chondrocytes in three-dimensional alginate culture. RESULTS Effect of LIUS on the expression of cartilage matrix proteins C-28/I2 cells were stimulated with LIUS, and the optimal conditions for incubation and treatment times were examined in terms of type II collagen and aggrecan expression by RT-PCR. The mRNA level of type II collagen was the highest after 3 hr and that of aggrecan was gradually increasing by time, when cells were treated with LIUS for 15 min. Role of SACs in the LIUS signal When examined at 1, 3 and 6 hr after stimulation by RT-PCR, the LIUS effects on the mRNA levels of type II collagen and aggrecan were reduced by gadolinium treatment depending on time Role of integrins in the LIUS signal C-28/I2 cells were pre-incubated with the inhibitor (GRGDSP) or a control peptide (GRADSP) for 10 min before LIUS treatment. The mRNA levels of type II collagen and aggrecan were clearly induced by LIUS in the presence of GRADSP but were lower than the untreated control (0 hr) when GRGDSP was co-treated. MAPKs as downstream mediators of LIUS signal The phosphorylation of ERK and JNK was induced by LIUS but that of p38 kinase was not CONCLUSION These results suggest that the LIUS signal might be mediated via canonical mechanoreceptors of SACs and integrins and subsequently through JNK and ERK pathways. Further studies are necessary to understand more details of the LIUS signaling network and regulation mechanisms. In addition, our ongoing studies in a 3-D culture of chondrocytes would give more important information about the cellular and molecular mechanism(s) of LIUS effects on development of chondrogenic phenotypes. REFERENCES 1. Feril, L.B. Jr. and Kondo, T. Biological effects of low intensity ultrasound: the mechanism involved and its implications on therapy and on biosafety of ultrasound

Dynamics in treatment response and disease progression of metastatic colorectal cancer (mCRC) patients with focus on BRAF status and primary tumor location: analysis of untreated RAS-wild-type mCRC patients receiving FOLFOXIRI either with or without panitumumab in the VOLFI trial (AIO KRK0109)

Purpose: In mCRC, disease dynamics may play a critical role in the understanding of long-term outcome. We evaluated depth of response (DpR), time to DpR, and post-DpR survival as relevant endpoints. Methods: We analyzed DpR by central review of computer tomography images (change from baseline to smallest tumor diameter), early tumor shrinkage (≥ 20% reduction in tumor diameter at first reassessment), time to DpR (study randomization to DpR-image), post-DpR progression-free survival (pPFS = DpR-image to tumor progression or death), and post-DpR overall survival (pOS = DpR-image to death) with special focus on BRAF status in 66 patients and primary tumor site in 86 patients treated within the VOLFI-trial, respectively. Results: BRAF wild-type (BRAF-WT) compared to BRAF mutant (BRAF-MT) patients had greater DpR (− 57.6% vs. − 40.8%, p = 0.013) with a comparable time to DpR [4.0 (95% CI 3.1–4.4) vs. 3.9 (95% CI 2.5–5.5) months; p = 0.8852]. pPFS was 6.5 (95% CI 4.9–8.0) versus 2.6 (95% CI 1.2–4.0) months in favor of BRAF-WT patients (HR 0.24 (95% CI 0.11–0.53); p < 0.001). This transferred into a significant difference in pOS [33.6 (95% CI 26.0–41.3) vs. 5.4 (95% CI 5.0–5.9) months; HR 0.27 (95% CI 0.13–0.55); p < 0.001]. Similar observations were made for patients stratified for primary tumor site. Conclusions: BRAF-MT patients derive a less profound treatment response compared to BRAF-WT patients. The difference in outcome according to BRAF status is evident after achievement of DpR with BRAF-MT patients hardly deriving any further disease control beyond DpR. Our observations hint towards an aggressive tumor evolution in BRAF-MT tumors, which may already be molecularly detectable at the time of DpR

Phosphoinositide 3-kinase: a critical signalling event in pulmonary cells

Phosphoinositide 3-kinases (PI-3Ks) are enzymes that generate lipid second messenger molecules, resulting in the activation of multiple intracellular signalling cascades. These events regulate a broad array of cellular responses including survival, activation, differentiation and proliferation and are now recognised to have a key role in a number of physiological and pathophysiological processes in the lung. PI-3Ks contribute to the pathogenesis of asthma by influencing the proliferation of airways smooth muscle and the recruitment of eosinophils, and affect the balance between the harmful and protective responses in pulmonary inflammation and infection by the modulation of granulocyte recruitment, activation and apoptosis. In addition they also seem to exert a critical influence on the malignant phenotype of small cell lung cancer. PI-3K isoforms and their downstream targets thus provide novel therapeutic targets for intervention in a broad spectrum of respiratory diseases

Genotyping of circulating tumor DNA in cholangiocarcinoma reveals diagnostic and prognostic information

Diagnosis of Cholangiocarcinoma (CCA) is difficult, thus a noninvasive approach towards (i) assessing and (ii) monitoring the tumor-specific mutational profile is desirable to improve diagnosis and tailor treatment. Tumor tissue and corresponding ctDNA samples were collected from patients with CCA prior to and during chemotherapy and were subjected to deep sequencing of 15 genes frequently mutated in CCA. A set of ctDNA samples was also submitted for 710 gene oncopanel sequencing to identify progression signatures. The blood/tissue concordance was 74% overall and 92% for intrahepatic tumors only. Variant allele frequency (VAF) in ctDNA correlated with tumor load and in the group of intrahepatic CCA with PFS. 63% of therapy naive patients had their mutational profile changed during chemotherapy. A set of 76 potential progression driver genes was identified among 710 candidates. The molecular landscape of CCA is accessible via ctDNA. This could be helpful to facilitate diagnosis and personalize and adapt therapeutic strategies

Transcriptional changes and the role of ONECUT1 in hPSC pancreatic differentiation

Cell type specification during pancreatic development is tightly controlled by a transcriptional and epigenetic network. The precise role of most transcription factors, however, has been only described in mice. To convey such concepts to human pancreatic development, alternative model systems such as pancreatic in vitro differentiation of human pluripotent stem cells can be employed. Here, we analyzed stage-specific RNA-, ChIP-, and ATAC-sequencing data to dissect transcriptional and regulatory mechanisms during pancreatic development. Transcriptome and open chromatin maps of pancreatic differentiation from human pluripotent stem cells provide a stage-specific pattern of known pancreatic transcription factors and indicate ONECUT1 as a crucial fate regulator in pancreas progenitors. Moreover, our data suggest that ONECUT1 is also involved in preparing pancreatic progenitors for later endocrine specification. The dissection of the transcriptional and regulatory circuitry revealed an important role for ONECUT1 within such network and will serve as resource to study human development and disease

Randomised, open-label, phase II study of Gemcitabine with and without IMM-101 for advanced pancreatic cancer

Background: Immune Modulation and Gemcitabine Evaluation-1, a randomised, open-label, phase II, first-line, proof of concept study (NCT01303172), explored safety and tolerability of IMM-101 (heat-killed Mycobacterium obuense; NCTC 13365) with gemcitabine (GEM) in advanced pancreatic ductal adenocarcinoma. Methods: Patients were randomised (2 : 1) to IMM-101 (10 mg ml−l intradermally)+GEM (1000 mg m−2 intravenously; n=75), or GEM alone (n=35). Safety was assessed on frequency and incidence of adverse events (AEs). Overall survival (OS), progression-free survival (PFS) and overall response rate (ORR) were collected. Results: IMM-101 was well tolerated with a similar rate of AE and serious adverse event reporting in both groups after allowance for exposure. Median OS in the intent-to-treat population was 6.7 months for IMM-101+GEM v 5.6 months for GEM; while not significant, the hazard ratio (HR) numerically favoured IMM-101+GEM (HR, 0.68 (95% CI, 0.44–1.04, P=0.074). In a pre-defined metastatic subgroup (84%), OS was significantly improved from 4.4 to 7.0 months in favour of IMM-101+GEM (HR, 0.54, 95% CI 0.33–0.87, P=0.01). Conclusions: IMM-101 with GEM was as safe and well tolerated as GEM alone, and there was a suggestion of a beneficial effect on survival in patients with metastatic disease. This warrants further evaluation in an adequately powered confirmatory study