Exosomal TUBB3 mRNA expression of metastatic castration-resistant prostate cancer patients: Association with patient outcome under abiraterone.

BACKGROUND: To use ddPCR to quantify plasma exosomal class III ß-tubulin (ßIII-tubulin, TUBB3, encoded by the TUBB3 gene) mRNA expression in metastatic castration-resistant prostate cancer (mCRPC) patients, and study the association of this expression with abiraterone efficacy. METHODS: Blood samples were prospectively collected from 52 mCRPC patients using abiraterone as first-line therapy to measure plasma exosomal TUBB3 mRNA expression value before the initiation of abiraterone. Study endpoints were PSA response rate, PSA-progression-free survival (PSA-PFS), and overall survival (OS, from CRPC to death). RESULTS: Patients with positive exosomal TUBB3 expression showed shorter PSA-PFS (negative TUBB3 vs. positive TUBB3: 11.0 vs. 7.9 months; p = 0.014). Further analysis demonstrated that patients with strongly positive exosomal TUBB3 (>20 copies/20 µl) was associated with even shorter PSA-PFS (negative TUBB3 vs. positive TUBB3 [<20 copies/20 µl] vs. strongly positive TUBB3 [>20 copies/20 µl]: 11.0 vs. 8.3 vs. 3.6 months, p = 0.005). In multivariate analyzes, TUBB3 (+) (HR: 2.114, p = 0.033) and ECOG score >2 (HR: 3.039, p = 0.006) were independent prognosticators of poor PSA-PFS. PSA response and OS did not present significant differences. CONCLUSION: The exosomal TUBB3 mRNA expression level is associated with poor PSA-PFS of abiraterone in mCRPC patients. The detection of exosomal TUBB3 can be valuable in their management.

Novel proteins associated with chronic intermittent hypoxia and obstructive sleep apnea: From rat model to clinical evidence.

OBJECTIVE: To screen for obstructive sleep apnea (OSA) biomarkers, isobaric tags for relative and absolute quantitation (iTRAQ)-labeled quantitative proteomics assay was used to identify differentially expressed proteins (DEPs) during chronic intermittent hypoxia (CIH). METHOD: The iTRAQ technique was applied to compare DEPs in the serum of a CIH rat model and control group. Biological analysis of DEPs was performed using Gene Ontology and Kyoto Encyclopedia to explore related biological functions and signaling pathways. Enzyme-linked immunosorbent assay (ELISA) was performed to validate their expression in sera from patients with OSA and CIH rats. RESULTS: Twenty-three DEPs (fold change ≥1.2 or ≤0.833, p<0.05) were identified, and two DEPs (unique peptides>3 and higher coverage) were further verified by ELISA in the CIH rat model and OSA subject: apolipoprotein A-IV (APOA4, p<0.05) and Tubulin alpha-1A chain (TUBA1A, p<0.05). Both groups showed significant differences in the expression levels of DEPs between the CIH and control groups and the severe OSA and non-OSA groups. APOA4 was found to be upregulated and TUBA1A downregulated in both the sera from OSA patients and CIH rats, on comparing proteomics results with clinical results. There were two pathways that involved three DEPs, the mitogen-activated protein kinase (MAPK) signaling pathway (p<0.05) and cytokine-cytokine receptor interaction (p<0.05). CONCLUSION: APOA4 and TUBA1A may be potential novel biomarkers for CIH and OSA, and may play an important role in the development of OSA complications.

Identification of novel TUBB1 variants in patients with macrothrombocytopenia.

Background/aim: Macrothrombocytopenia is an autosomal-dominant disorder characterized by increased platelet size and a decreased number of circulating platelets. The membrane skeleton and the link between actin filaments of the skeleton and microtubules, which consist of alpha and beta tubulin [including the tubulin beta-1 chain (TUBB1)] heterodimers, are important for normal platelet morphology, and defects in these systems are associated with macrothrombocytopenia. Materials and methods: In this study, we sequenced the exons of the TUBB1 gene using DNA isolated from the peripheral blood samples of healthy controls (n = 47) and patients with macrothrombocytopenia (n = 37) from Turkey. The TUBB1 expression levels in fractioned blood samples from patients and healthy controls were analyzed by RT-qPCR and Western blot. Microtubule organization of the platelets in the peripheral blood smears of patients, and in mutant TUBB1-transfected HeLa cells, were analyzed by immunofluorescence staining. Results: A new TUBB1 c.803G>T (p.T178T) variant was detected in all of the control and patient samples. Importantly, we found 3 new heterozygous TUBB1 variants predicting amino acid substitutions: G146R (in 1 patient), E123Q (in 1 patient), and T274M (in 4 patients); the latter variant was associated with milder thrombocytopenia in cancer patients treated with paclitaxel. Ectopic expression of TUBB1 T274M/R307H variant in HeLa cells resulted in irregular microtubule organization. Conclusion: Further clinical and functional studies of the newly identified TUBB1 variants may offer important insights into their pathogenicity in macrothrombocytopenia.

Plasma ß-III tubulin, neurofilament light chain and glial fibrillary acidic protein are associated with neurodegeneration and progression in schizophrenia.

Schizophrenia is a progressive disorder characterized by multiple psychotic relapses. After every relapse, patients may not fully recover, and this may lead to a progressive loss of functionality. Pharmacological treatment represents a key factor to minimize the biological, psychological and psychosocial impact of the disorder. The number of relapses and the duration of psychotic episodes induce a potential neuronal damage and subsequently, neurodegenerative processes. Thus, a comparative study was performed, including forty healthy controls and forty-two SZ patients divided into first-episode psychosis (FEP) and chronic SZ (CSZ) subgroups, where the CSZ sub group was subdivided by antipsychotic treatment. In order to measure the potential neuronal damage, plasma levels of ß-III tubulin, neurofilament light chain (Nf-L), and glial fibrillary acidic protein (GFAP) were performed. The results revealed that the levels of these proteins were increased in the SZ group compared to the control group (P < 0.05). Moreover, multiple comparison analysis showed highly significant levels of ß-III tubulin (P = 0.0002), Nf-L (P = 0.0403) and GFAP (P < 0.015) in the subgroup of CSZ clozapine-treated. In conclusion, ß-III tubulin, Nf-L and GFAP proteins may be potential biomarkers of neurodegeneration and progression in SZ.

Novel Approach for Detecting the Neurological or Behavioral Impact of Physiological Episodes (PEs) in Military Aircraft Crews.

INTRODUCTION: Military and civil aviation have documented physiological episodes among aircrews. Therefore, continued efforts are being made to improve the internal environment. Studies have shown that exposures to many organic compounds present in emissions are known to cause a variety of physiological symptoms. We hypothesize that these compounds may reversibly inhibit acetylcholinesterase, which may disrupt synaptic signaling. As a result, neural proteins leak through the damaged blood-brain barrier into the blood and in some, elicit an autoimmune response. MATERIALS AND METHODS: Neural-specific autoantibodies of immunoglobulin-G (IgG) class were estimated by the Western blotting technique in the sera of 26 aircrew members and compared with the sera of 19 normal healthy nonaircrew members, used as controls. RESULTS: We found significantly elevated levels of circulating IgG-class autoantibodies to neurofilament triplet proteins, tubulin, microtubule-associated tau proteins (Tau), microtubule-associated protein-2, myelin basic protein, and glial fibrillary acidic protein, but not S100 calcium-binding protein B compared to healthy controls. CONCLUSION: Repetitive physiological episodes may initiate cellular injury, leading to neuronal degeneration in selected individuals. Diagnosis and intervention should occur at early postinjury periods. Use of blood-based biomarkers to assess subclinical brain injury would help in both diagnosis and treatment.

Platelet dysfunction caused by a novel thromboxane A2 receptor mutation and congenital thrombocytopenia in a case of mild bleeding.

Chronic hemorrhagic diathesis in patients showing normal levels of plasmatic clotting factors strongly suggests for congenital platelet disorders. We report on a pediatric patient (male, 3 years, D1) with mild bleeding. A sibling (D2), his mother (D3) and father (D4) were included for laboratory investigation. Platelet counts in D1, D2 and D4 indicated mild thrombocytopenia (100 Gpt/L). D1 and D3 platelets showed significantly diminished aggregation response on arachidonic acid and U46619 stimulation. Immunostaining for platelet proteins on blood smears of D1 and D2 indicated defects in ß1-tubulin. Exon sequencing of TBXA2R and TUBB1 revealed heterozygosity for the novel TBXA2R*c.908T>C (p.L303P) mutation in D1 and D3. TUBB1 was either wild type (D2, D3) or heterozygous (D1, D4) for the common polymorphism TUBB1*c.920G>A (rs6070697; p.R307H). In conclusion, the bleeding phenotype of the index patient can be explained by a diminished platelet function caused by the TBXA2R*c.908T>C mutation inherited from the mother and a mild thrombocytopenia with unknown molecular basis that is inherited from the father.

A Glanzmann thrombasthenia family associated with a TUBB1-related macrothrombocytopenia.

BACKGROUND: Macrothrombocytopenia (MTP) is a rare but enigmatic complication of Glanzmann thrombasthenia (GT), an inherited bleeding disorder caused by the absence of platelet aggregation due to deficiencies of the αIIbß3 integrin. OBJECTIVES: We report a family with type I GT and a prolonged bleeding time but unusually associated with congenital mild thrombocytopenia and platelet size heterogeneity with giant forms. METHODS AND RESULTS: Sanger sequencing of DNA from the propositus identified 2 heterozygous ITGB3 gene mutations: p.P189S and p.C210S both of which prevent αIIbß3 expression and are causative of GT but without explaining the presence of enlarged platelets. High-throughput screening led to the detection of a predicted disease-causing heterozygous mutation in the TUBB1 gene: p.G146R, encoding ß1-tubulin, a component of the platelet cytoskeleton and a gene where mutations are a known cause of MTP. CONCLUSIONS: Family screening confirmed that this rare phenotype results from oligogenic inheritance while suggesting that the GT phenotype dominates clinically.

Evaluation of α-tubulin, detyrosinated α-tubulin, and vimentin in CTCs: identification of the interaction between CTCs and blood cells through cytoskeletal elements.

BACKGROUND: Circulating tumor cells (CTCs) are the major players in the metastatic process. A potential mechanism of cell migration and invasion is the formation of microtentacles in tumor cells. These structures are supported by α-tubulin (TUB), detyrosinated α-tubulin (GLU), and vimentin (VIM). In the current study, we evaluated the expression of those cytoskeletal proteins in CTCs. METHODS: Forty patients with breast cancer (BC) (16 early and 24 metastatic) were enrolled in the study. CTCs were isolated using the ISET platform and stained with the following combinations of antibodies: pancytokeratin (CK)/VIM/TUB and CK/VIM/GLU. Samples were analyzed with the ARIOL platform and confocal laser scanning microscopy. RESULTS: Fluorescence quantification revealed that the ratios CK/TUB, CK/VIM, and CK/GLU were statistically increased in MCF7 compared with more aggressive cell lines (SKBR3 and MDA-MB-231). In addition, all of these ratios were statistically increased in MCF7 cells compared with metastatic BC patients' CTCs (p = 0.0001, p = 0.0001, and p = 0.003, respectively). Interestingly, intercellular connections among CTCs and between CTCs and blood cells through cytoskeleton bridges were revealed, whereas microtentacles were increased in patients with CTC clusters. These intercellular connections were supported by TUB, VIM, and GLU. Quantification of the examined molecules revealed that the median intensity of TUB, GLU, and VIM was significantly increased in patients with metastatic BC compared with those with early disease (TUB, 62.27 vs 11.5, p = 0.0001; GLU, 6.99 vs 5.29, p = 0.029; and VIM, 8.24 vs 5.38, p = 0.0001, respectively). CONCLUSIONS: CTCs from patients with BC aggregate to each other and to blood cells through cytoskeletal protrusions, supported by VIM, TUB, and GLU. Quantification of these molecules could potentially identify CTCs related to more aggressive disease.

Investigation of serum biomarkers in primary gout patients using iTRAQ-based screening.

OBJECTIVES: Primary gout is a major disease that affects human health; however, its pathogenesis is not well known. The purpose of this study was to identify biomarkers to explore the underlying mechanisms of primary gout. METHODS: We used the isobaric tags for relative and absolute quantitation (iTRAQ) technique combined with liquid chromatography-tandem mass spectrometry to screen differentially expressed proteins between gout patients and controls. We also identified proteins potentially involved in gout pathogenesis by analysing biological processes, cellular components, molecular functions, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and protein-protein interactions. We further verified some samples using enzyme-linked immunosorbent assay (ELISA). Statistical analyses were carried out using SPSS v. 20.0 and ROC (receiver operating characterstic) curve analyses were carried out using Medcalc software. Two-sided p-values <0.05 were deemed to be statistically significant for all analyses. RESULTS: We identified 95 differentially expressed proteins (50 up-regulated and 45 down-regulated), and selected nine proteins (α-enolase (ENOA), glyceraldehyde-3-phosphate dehydrogenase (G3P), complement component C9 (CO9), profilin-1 (PROF1), lipopolysaccharide-binding protein (LBP), tubulin beta-4A chain (TBB4A), phosphoglycerate kinase (PGK1), glucose-6-phosphate isomerase (G6PI), and transketolase (TKT)) for verification. This showed that the level of TBB4A was significantly higher in primary gout than in controls (p=0.023). CONCLUSIONS: iTRAQ technology was useful in the selection of differentially expressed proteins from proteomes, and provides a strong theoretical basis for the study of biomarkers and mechanisms in primary gout. In addition, TBB4A protein may be associated with primary gout.

Platelet-predominate gene expression and reticulated platelets in nonvalvular atrial fibrillation: Effect of pulmonary veins isolation.

INTRODUCTION: Reticulated platelet (RP) content is increased in nonvalvular atrial fibrillation (NVAF). The purpose of this study was to determine if platelet content, morphology, and RP proportion are modulated by platelet genes. METHODS AND RESULTS: Expression of six platelet-predominate genes impacting platelet formation and release, platelet count, and RP content was assessed in NVAF patients before and 3-4 months after pulmonary veins isolation (PVI) and compared to normal sinus rhythm (NSR) controls. RNA from isolated platelets was reverse-transcribed assayed against selected genes utilizing real-time qPCR, and expressed as mean cycle threshold (ΔCt) using beta-2-microglobulin as endogenous control. RP content was assessed by flow cytometry. A fourfold lower expression of CFL1 gene coding for nonmuscle cofilin (7.8 ± 0.9 vs. 5.7 ± 1.6, P < 0.001) and twofold lower expression of four other genes were associated with similar platelet counts but fourfold higher (28.7+7.0 vs. 6.7+5.4, P < 0.001) RP content (%) in 97 NVAF cases compared to 51 NSR controls. Three to 4 months after PVI, RP decreased by 28%, while CFL1 gene expression increased over twofold but TUBA4A gene expression decreased almost twofold; NFE2 and MYL6 gene expression remained unchanged. CONCLUSIONS: NVAF is associated with notable downregulation of genes directing platelet production and size but increased RP content. PVI impacts the expression of many of these genes, implying a direct relationship between atrial fibrillation and platelet biogenesis.

Biomarkers predicting chemotherapy response in head and neck squamous cell carcinoma: a review.

BACKGROUND: Biomarkers are increasingly being used in many cancers to select patients for oncological treatment paradigms based on their inherent genetic properties. However, in head and neck cancers, there are no personalised therapies available outside the context of a clinical trial. A number of studies suggest there are intrinsic tumour properties of head and neck cancers that affect their response to chemotherapeutic agents. This paper aimed to review their evidence base. METHOD: A narrative review was conducted following a search of the PubMed database. RESULTS AND CONCLUSION: The review identified a number of biomarkers predicting response to chemotherapy in head and neck cancers. The paper discusses these in detail, and explores where future research could be directed in order to deliver personalised therapies for patients with head and neck cancers.

Identification alpha-2-HS-glycoprotein precursor and tubulin beta chain as serology diagnosis biomarker of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) remains a major worldwide cause of cancer-related morbidity and mortality largely due to the insidious onset of the disease. The current clinical procedures utilized for disease diagnosis are invasive, unpleasant, and inconvenient. Hence, the need for simple blood tests that could be used for the early detection is crucial for its ultimate control and prevention. METHODS: The present work is a case-control study focused on proteomic analysis of serum of healthy volunteers and CRC patients by the ClinProt profiling technology based on mass spectrometry. This approach allowed to identifying a pattern of proteins/peptides able to differentiate the studied populations. Moreover, some of peptides differentially expressed in the serum of patients as compared to healthy volunteers were identified by LTQ Orbitrap XL. RESULTS: A Quick Classifier Algorithm was used to construct the peptidome patterns (m/z 1208, 1467, 1505, 1618, 1656 and 4215) for the identification of CRC from healthy volunteers with accuracy close to 100% (>CEA, P < 0.05). Peaks at m/z 1505 and 1618 were identified as alpha-2-HS-glycoprotein precursor and tubulin beta chain, respectively. CONCLUSIONS: Alpha-2-HS-glycoprotein precursor and tubulin beta chain could be involved in the pathogenesis of CRC and perform as potential serology diagnosis biomarker. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4796578761089186.

Paxillin suppresses the proliferation of HPS rat serum treated PASMCs by up-regulating the expression of cytoskeletal proteins.

Hepatopulmonary syndrome (HPS) is a triad of advanced liver disease, intrapulmonary vasodilatation (IPVD), and arterial hypoxemia. The arterial hypoxemia induces pulmonary vascular remodelling (PVR). In recent studies, the role of the proliferation of pulmonary artery smooth muscle cells (PASMCs) in PVR associated with HPS has been established; the changes in cytoskeletal proteins play an essential role in the proliferation of PASMCs. Little is known about the relevance of cytoskeletal protein expression or the molecular mechanisms of PVR associated with HPS. In addition, it has been identified that paxillin could influence the cytoskeletal protein expression by some important signaling pathways in many diseases, including lung cancer and liver cancer. In this study, we found that HPS rat serum from a common bile duct ligation (CBDL) rat model decreased the expression of cytoskeletal proteins (α-actin, α-tubulin, and destrin) and enhanced the expression levels of paxillin mRNA and protein in PASMCs. After silencing paxillin with siRNA, we found that the down-regulation of cytoskeletal protein expression, induced by the HPS rat serum, was reversed. Additionally, we reported that HPS rat serum improved the proliferation of PASMCs and down-regulation of paxillin could significantly inhibit this variation. These findings suggest that the up-regulation of cytoskeletal protein expression, induced by the paxillin, may cause the dysregulation of PASMC proliferation as well as play a fundamental role in PVR associated with HPS. In conclusion, down-regulation of paxillin by siRNA results in the inhibition of the dysregulation of cytoskeletal proteins and proliferation of PASMCs, suggesting a potential therapeutic effect on PVR associated with HPS.

Detection of antibodies to self-antigens (K-alpha 1 tubulin, collagen I, II, IV, and V, myosin, and vimentin) by enzyme-linked immunosorbent assay (ELISA).

The enzyme-linked immunosorbent assay (ELISA) is a widely used technique for detecting antibodies (Abs) and is employed in clinical laboratories to identify Abs against various self-antigens-autoAb development and quantitation. This method relies on specific antigen-Ab interactions where one of the components is immobilized on a solid surface. Using this method, the concentrations of antigens or Ab present in the serum can be quantified with high specificity and accuracy. Here, we describe the detection of autoAbs to various self-antigens with different tissue restriction patterns which includes collagens, k-α1 tubulin, vimentin, and myosin. We also discuss their relevance in monitoring for rejection following solid organ transplantation.

Identification of tubulin beta chain, thymosin beta-4-like protein 3, and cytochrome b-c1 complex subunit 1 as serological diagnostic biomarkers of gastric cancer.

OBJECTIVE: Despite major advances in its diagnosis and treatment, gastric cancer (GC) remains a major life-threatening disease. Treatment of the disease is further aggravated by the lack of diagnostic biomarkers that can aid in the early detection of GC and promote its favorable prognosis. The present work aims to identify novel diagnostic biomarkers for GC. DESIGN AND METHODS: The present work is a case-control study that focuses on proteomic analysis of serum from healthy volunteers and GC patients using ClinProt profiling technology based on mass spectrometry. A pattern of proteins/peptides with the ability to differentiate the studied populations was identified. Deregulated proteins/peptides differentially expressed in the serum of patients compared with healthy volunteers were identified by mass spectroscopy. RESULTS: A pattern of proteins/peptides consisting of four protein/peptide peaks at m/z 1467, 1867, 2701, and 2094 was identified. These protein/peptide peaks were able to differentiate the studied populations with close to 100% sensitivity and specificity. Three of the deregulated proteins/peptides at m/z 1867, 2701, and 2094 were identified by mass spectroscopy (LTQ Orbitrap XL) as tubulin beta chain, thymosin beta-4-like protein 3, and cytochrome b-c1 complex subunit 1, respectively. CONCLUSIONS: The pattern of proteins/peptides identified in the present work shows great potential for GC diagnosis. Deregulated proteins of tubulin beta chain, thymosin beta-4-like protein 3, and cytochrome b-c1 complex subunit 1 may be involved in the pathogenesis of GC and serve as potential serological diagnostic biomarkers.

Tubulin beta chain, filamin A alpha isoform 1, and cytochrome b-c1 complex subunit 1 as serological diagnostic biomarkers of esophageal squamous cell carcinoma: a proteomics study.

Despite the major advances in diagnosis and treatment, esophageal squamous cell carcinoma (ESCC) remains a major life-threatening disease. Early diagnosis is critical for guiding the therapeutic management of ESCC. This case-control study focused on the proteomic analysis of serum of healthy volunteers and ESCC patients using the ClinProt profiling technology based on mass spectrometry. A total of 80 healthy volunteers and 119 ESCC patients were enrolled. We identified a pattern of proteins/peptides (including m/z 1867, 2700, and 2094) and differentiated ESCC patients from healthy volunteers with sensitivity and specificity close to 100%. Using mass spectrometry (LTQ orbitrap XL), tubulin beta chain, filamin A alpha isoform 1, and cytochrome b-c1 complex subunit 1 were identified as the three differentially expressed proteins/peptides in the patient serum. These three dysregulated proteins/peptides could be involved in the pathogenesis of ESCC and may serve as putative serological diagnostic biomarkers of ESCC. We suggest that further proteomics and multi-omics research are warranted to identify novel post-genomics diagnostics that can in the future pave the way for personalized medicine for patients with ESCC, a cancer for which we currently lack an integrated battery of diagnostics in the field of oncology.

ßIII-Tubulin: biomarker of taxane resistance or drug target?

INTRODUCTION: ßIII-Tubulin (TUBB3) is predominantly expressed in neurons of the central and peripheral nervous systems, while in normal non-neoplastic tissues it is barely detectable. By contrast, this cytoskeletal protein is abundant in a wide range of tumors. ßIII-Tubulin is linked to dynamic instability of microtubules (MTs), weakening the effects of agents interfering with MT polymerization. Based on this principle, early studies introduced the classical theory linking ßIII-tubulin with a mechanism of counteracting taxane activity and accordingly, prompted its investigation as a predictive biomarker of taxane resistance. AREAS COVERED: We reviewed 59 translational studies, including cohorts from lung, ovarian, breast, gastric, colorectal and various miscellaneous cancers subject to different chemotherapy regimens. EXPERT OPINION: ßIII-Tubulin functions more as a prognostic factor than as a predictor of response to chemotherapy. We believe this view can be explained by ßIII-tubulin's association with prosurvival pathways in the early steps of the metastatic process. Its prognostic response increases if combined with additional biomarkers that regulate its expression, since ßIII-tubulin can be expressed in conditions, such as estrogen exposure, unrelated to survival mechanisms and without any predictive activity. Additional avenues for therapeutic intervention could emerge if drugs are designed to directly target ßIII-tubulin and its mechanism of regulation.

Serum levels of TUBB3 correlate with clinical outcome in Chinese patients with advanced gastric cancer receiving first-line paclitaxel plus capecitabine.

The overexpression of ß-tubulin III (TUBB3) in tumor tissues was reversely related with the efficacy of paclitaxel and clinical outcome in different cancers. In this study, we aimed to investigate the association between serum levels of TUBB3 and clinical outcome in advanced gastric cancer patients receiving first-line paclitaxel plus capecitabine. One hundred and twenty-eight advanced gastric cancer patients receiving first-line paclitaxel plus capecitabine in Peking University Cancer Hospital from December 2006 to October 2010 were enrolled in the study. Serum samples from 32 healthy individuals were used as controls. TUBB3 expression level in advanced gastric cancer was significantly higher than that in healthy control group (31.6 ± 17.8 ng/mL vs. 16.9 ± 3.8 ng/mL, p < 0.001). For all patients, the clinical benefit rate (CBR), median progression-free survival (PFS), and overall survival (OS) were 55.6 %, 179 and 306 days, respectively. The CBR, median PFS, and OS in patients with low (n = 27) and high levels (n = 101) of TUBB3 were 95.8 %/45.1 % (low vs. high, p < 0.001), 190 days/166 days (p = 0.064), and 360 days/297 days (p = 0.023), respectively. Cox multivariate regression analysis demonstrated that the serum levels of TUBB3 were an independent prognostic factor for advanced gastric cancer patients (HR = 1.950; 95 % CI, 1.242-3.062; p = 0.004). This study indicated that low levels of TUBB3 in serum could predict better response and survival for advanced gastric cancer patients receiving paclitaxel plus capecitabine, which could be used to select patients who would benefit from this regimen.

Clinical, pharmacodynamic, and pharmacokinetic evaluation of BNC105P: a phase I trial of a novel vascular disrupting agent and inhibitor of cancer cell proliferation.

PURPOSE: To determine the recommended phase II dose and evaluate the safety and toxicity profile and pharmacokinetic (PK) and pharmacodynamic (PD) effects of BNC105P, an inhibitor of tubulin polymerization that has vascular disrupting and antiproliferative effects. EXPERIMENTAL DESIGN: BNC105P was administered as a 10-minute infusion on days 1 and 8 of a 21-day cycle in a first-in-human phase I study. A dynamic accelerated dose titration method was used for dose escalation. Plasma concentrations of BNC105P (phosphate prodrug) and BNC105 (active agent) were determined. PD assessments were carried out using dynamic contrast enhanced (DCE)-MRI and analysis of a blood-borne biomarker. RESULTS: Twenty-one subjects with advanced solid tumors were enrolled on 6 dose levels (range: 2.1-18.9 mg/m(2)). The recommended dose level was 16 mg/m(2) and was well tolerated. BNC105P (prodrug) rapidly converted to BNC105 with a half-life of 0.13 hours. Plasma concentrations of BNC105 generally increased in proportion to dose with a half-life of 0.57 hours. Pharmacodymanically active plasma levels were obtained with a dose dependant reduction in the levels of polymerized tubulin (on-target action) being observed in PBMCs. DCE-MRI also indicated blood flow changes in the tumor lesions of a number of subjects. CONCLUSIONS: BNC105P has a favorable toxicity profile at the recommended dose of 16 mg/m(2) and is associated with PD changes consistent with its known mechanism of action. Phase II studies in renal cancer and mesothelioma have commenced.