Dumnoensun Pruksakorn

Metabolic alteration of HepG2 in scaffold‐based 3‐D culture: Proteomic approach

3‐D cell culture models are important in cancer biology since they provide improved understanding of tumor microenvironment. We have established a 3‐D culture model using HepG2 in natural collagen‐based scaffold to mimic the development of small avascular tumor in vivo. Morphological characterization showed that HepG2 colonies grew within the interior of the scaffold and showed enhanced extracellular matrix deposition. High levels of cell proliferation in the outermost regions of the scaffold created a hypoxic microenvironment in the 3‐D culture system, as indicated by hypoxia‐inducible factor‐1α stabilization, detectable by Western blotting and immunohistochemistry. Proteomic studies showed decreased expression of several mitochondrial proteins and increased expression of proteins in anaerobic glycolysis under 3‐D culture compared to monolayer culture. Creatine kinase was also upregulated in 3‐D culture, indicating its possible role as an important energy buffer system under hypoxic microenvironment. Increased levels of proteins in nucleotide metabolism may relate to cellular energy. Thus, our results suggest that HepG2 cells under 3‐D culture adapt their energy metabolism in response to hypoxic conditions. Metabolic alterations in the 3‐D culture model may relate to physiological changes relevant to development of small avascular tumor in vivo and their study may improve future therapeutic strategies.

Chondroitin sulfate epitope (WF6) and hyaluronic acid as serum markers of cartilage degeneration in patients following anterior cruciate ligament injury

Serum chondroitin sulfate epitope (WF6) and hyaluronic acid (HA) levels were determined to be of clinical relevance to an anterior cruciate ligament (ACL) injury. This cross-sectional study recruited participants from two distinct groups. Group A was comprised of 74 healthy controls, and group B consisted of 33 ACL injury patients. Serum samples were taken and assayed by a competitive immunoassay with monoclonal antibody WF6. Serum HA was also determined by an ELISA-based assay using biotinylated HA-binding proteins. Both groups A and B shared similar values of age, body mass index, white blood cell count and percentage of polymorphonuclear cells. ESR levels were also shown to be within normal limits. The serum WF6 epitope levels of group B were significantly higher than those of group A, whereas serum HA levels were not different between the two groups. The serum WF6 epitope level is more sensitive to changes in articular cartilage due to a non-inflammatory instability condition than the serum HA level, and should prove to be one of the most promising assays for early post-traumatic arthritis detection.

Prospective evaluation of serum biomarker levels and cartilage repair by autologous chondrocyte transplantation and subchondral drilling in a canine model

IntroductionThe purpose of this study was to evaluate serum chondroitin sulfate (CS) and hyaluronic acid (HA) levels and the capability of cartilage repair of full-thickness cartilage defects after treatment with two different fundamental surgical techniques: autologous chondrocyte transplantation (AC) and subchondral drilling (SD).MethodsA 4-mm-diameter full-thickness cartilage defect was created in each of 10 skeletally mature male outbred dogs. The dogs were randomly separated into two groups. Groups A and B were treated with AC and SD, respectively. An evaluation was made at the 24th week of the experiment. Serum was analyzed prospectively – preoperatively and at 6-week intervals – for CS and HA levels by enzyme-linked immunosorbent assay (ELISA) and ELISA-based assays, respectively.ResultsThe cartilage repair assessment score (median ± standard deviation) of group A (9.5 ± 2.5) was significantly higher than that of group B (2.5 ± 1.3) (P < 0.05). Group A also demonstrated a better quality of hyaline-like cartilage repair. Prospective analysis of serum WF6 and HA levels between the two groups did not show any significant difference. Serum WF6 levels at the 24th week of the experiment had a negative correlation (r = -0.69, P < 0.05) with the cartilage repair assessment score, whereas serum HA levels tended to correlate positively (r = 0.46, 0.1 <P < 0.05).ConclusionsAC treatment provides superior results to SD treatment, according to morphology, histology, and cartilage marker levels. AC treatment demonstrated a smoother surface, less fissure, better border integration, and a more reliable outcome of repairing cartilage. Moreover, a decreasing level of serum WF6, which correlated with good quality of the repairing tissue at the end of the follow-up period, was found predominantly in the AC group. Serum WF6 therefore should be further explored as a sensitive marker for the noninvasive therapeutic evaluation of cartilage repair procedures.

Hyaluronan production and chondrogenic properties of primary human chondrocyte on gelatin based hematostatic spongostan scaffold

BackgroundAutologous chondrocyte transplantation is a promising technique for treatment of cartilage defects. Three dimensional chondrocyte cultures on a scaffold are widely used to retain the chondrogenic phenotype. Using a biodegradable gelatin scaffold is one option for the cell delivery system, but molecular and histological studies of the method have not yet been done.MethodsWe evaluated the chondrogenic property of the primary human chondrocyte on a gelatin scaffold as compared to a collagen scaffold over a period of 21 days. We examined the production of glycosaminoglycan by quantitative and histological analysis. Gene expression of cartilage-associated molecules was assessed by quantitative RT-PCR.ResultsThe gelatin scaffold showed the ability to promote chondrocyte expansion, chondrogenic phenotype retention at molecular and mRNA levels.ConclusionsThis scaffold is thus suitable for use as an in vitro model for chondrocyte 3D culture.

Overexpression of KH-type splicing regulatory protein regulates proliferation, migration, and implantation ability of osteosarcoma

Osteosarcoma is a common malignant bone tumor in children and adolescents. The current 5-year survival rate is ~60% and that seems to be reaching a plateau. In order to improve treatment outcomes of osteosarcoma, a better understanding of tumorigenesis and underlying molecular mechanisms is required for searching out possible new treatment targets. This study aimed to identify the potential proteins involving the pathogenesis of osteosarcoma using a proteomics approach. Proteins extracted from primary cell culture of osteosarcoma (n=7) and osteoblasts of cancellous bone (n=7) were studied. Using 2-DE based proteomics and LC-MS/MS analysis, we successfully determined seven differentially expressed protein spots. Four upregulated proteins and three downregulated proteins were observed in this study in which KH-type splicing regulatory protein (KSRP) was selected for further exploration. KSRP was significantly upregulated in osteosarcoma cells compared to osteoblasts using western blot assay. In addition, immunohistochemistry demonstrated that KSRP was also highly expressed in osteosarcoma tissue of independent cases from the experimental group. More importantly, KSRP silencing of osteosarcoma cell lines significantly decreased cell proliferation, migration ability, as well as implantation and growth ability in chick chorioallantoic membrane assay. Taken together, these findings demonstrate, that KSRP plays important roles in regulatory controls of osteosarcoma pathogenesis and serves as a potentially therapeutic target of osteosarcoma.

Exploring targeted therapy of osteosarcoma using proteomics data

Despite multimodal therapeutic treatments of osteosarcoma (OS), some patients develop resistance to currently available regimens and eventually end up with recurrent or metastatic outcomes. Many attempts have been made to discover effective drugs for improving outcome; however, due to the heterogeneity of the disease, new therapeutic options have not yet been identified. This study aims to explore potential targeted therapy related to protein profiles of OS. In this review of proteomics studies, we extracted data on differentially expressed proteins (DEPs) from archived literature in PubMed and our in-house repository. The data were divided into three experimental groups, DEPs in 1) OS/OB: OS vs osteoblastic (OB) cells, 2) metastasis: metastatic vs non-metastatic sublines plus fresh tissues from primary OS with and without pulmonary metastasis, and 3) chemoresistance: spheroid (higher chemoresistance) vs monolayer cells plus fresh tissues from biopsies from good and poor responders. All up-regulated protein entities in the list of DEPs were sorted and cross-referenced with identifiers of targets of US Food and Drug Administration (FDA)-approved agents and chemical inhibitors. We found that many targets of FDA-approved antineoplastic agents, mainly a group of epigenetic regulators, kinases, and proteasomes, were highly expressed in OS cells. Additionally, some overexpressed proteins were targets of FDA-approved non-cancer drugs, including immunosuppressive and antiarrhythmic drugs. The resulting list of chemical agents showed that some transferase enzyme inhibitors might have anticancer activity. We also explored common targets of OS/OB and metastasis groups, including amidophosphoribosyltransferase (PPAT), l-lactate dehydrogenase B chain (LDHB), and pyruvate kinase M2 (PKM2) as well as the common target of all categories, cathepsin D (CTSD). This study demonstrates the benefits of a text mining approach to exploring therapeutic targets related to protein expression patterns. These results suggest possible repurposing of some FDA-approved medicines for the treatment of OS and using chemical inhibitors in drug screening tests.

Pitfalls in imaging of musculoskeletal infections.

In musculoskeletal infections, imaging helps in the diagnosis and identification of disease extent. Musculoskeletal infections have variable clinical presentations related to host immune responses and virulence of pathogens. Occasionally, infectious process may mimic other entities such as autoimmune inflammatory diseases, tumors, or traumatic injuries, both clinically and radiologically. Identification of the disease extent is sometimes difficult, particularly when infection occurs in the damaged tissue. The key imaging feature of infection is formation of abscesses. Familiarity of the imaging patterns of the infectious process leads to correct diagnosis and appropriate treatment.

Expression patterns of class I histone deacetylases in osteosarcoma: a novel prognostic marker with potential therapeutic implications

Epigenetic aberrations are recognized as having pivotal roles in cancer etiology and progression. Histone deacetylases are among the most studied epigenetic modulators in various cancer types. The expression levels of class I histone deacetylase isoforms 1, 2, and 3 in patient-derived primary osteosarcoma cells (6 cases) was investigated, comparing them to normal bone graft-derived osteoblasts (6 cases) using the immunoblotting technique. Expression profiles of histone deacetylases in high-grade osteosarcoma tissue of 89 patients were examined and their association with clinicopathologic parameters and the patient survival was evaluated. Histone deacetylases were immunohistochemically stained on formalin-fixed paraffin-embedded biopsied tissue. Primary osteosarcoma cells expressed higher levels of histone deacetylase 1 and histone deacetylase 2, but lower levels of histone deacetylase 3 compared to benign osteoblasts. Overall, 82, 99, and 93% of 89 osteosarcomas showed nuclear expression of the histone deacetylase isoforms 1, 2, and 3, respectively. Low levels of histone deacetylase 1 were significantly associated with a high Enneking stage (P=0.014) and the presence of initial metastasis (P=0.040), while low levels of histone deacetylase 3 were significantly correlated with age >15 years (P=0.026). Univariate survival analysis found significantly shorter survival in the patients with a high Enneking stage (P<0.001), axial location (P=0.009), presence of initial metastasis (P<0.001), low-histone deacetylase 1 expression (P=0.038), and low-all-histone deacetylases expression (P=0.016). Multivariate survival analysis showed that only axial location (P=0.011) and low-all-histone deacetylases expression (P=0.039) were independent prognostic factors. In subgroup analysis of stage IIB patients (n=45), only axial location and low-all-histone deacetylases expression were associated with shorter survival in both univariate and multivariate analysis (axial location, P=0.008 and 0.010; low-all-HDACs, P=0.013 and 0.038, respectively). Low levels of all-histone deacetylases expression were significantly associated with advanced disease status and short survival. These findings may be a guide to future use of histone deacetylase inhibitors in osteosarcoma patients.

Prognostic score for life expectancy evaluation of lung cancer patients after bone metastasis

Background This study identifies the overall survival status of lung cancer patients with bone metastasis and metastasis patterns. Poor prognostic factors were identified to develop a scoring system for estimating survival period after bone metastasis. Methods A retrospective cohort analysis was performed at Chiang Mai University for the period January 1, 2006 and December 31, 2013. Time-to-event analysis was performed to estimate survival rate. The primary end point was death related to lung cancer. Univariate and multivariate analysis of the prognostic variables was done using the Coxs regression model. The score was derived from the corresponding estimated regression coefficients of significantly poor prognostic factors. Results A total of 505 lung cancer with bone metastasis patients were analyzed. Four hundred two cases (79.6%) were concurrent diagnosis and 103 (20.4%) were subsequent diagnosis. The median survival time of lung cancer after bone metastasis 148 days. Male gender and ECOG 3–4 were significant poor prognostic factors for lung cancer after bone metastasis, with hazard ratios of 1.42 (95% CI 1.17–1.73), and 1.30 (95% CI 1.06–1.60), respectively. Prognosis score was determined using the binary term present/not-present for those factors. The curve from prognostic score summations of 2, 1 and 0 presented a good discrimination of survival expectancy, showing an expected median survival time of approximately 109, 146, and 225 days, respectively. Conclusions Prognostic score is a clinically simple and easy method for estimating life expectancy and for guiding interventions in bone metastasis of lung cancer.

In vitro human chondrocyte culture on plasma-treated poly(glycerol sebacate) scaffolds

Porous poly(glycerol sebacate) (PGS) scaffolds were prepared using a salt leaching technique and subsequently surface modified by a low oxygen plasma treatment prior to the use in the in vitro culture of human chondrocytes. Condensation polymerization of glycerol and sebacic acid used at various mole ratios, i.e. 1:1, 1:1.25, and 1:1.5, was initially conducted to prepare PGS prepolymers. Porous elastomeric PGS scaffolds were directly fabricated from the mixtures of each prepolymer and 90% (w/w) NaCl particles and then subjected to the plasma treatment to enhance the surface hydrophilicity of the materials. The properties of both untreated and plasma-treated PGS scaffolds were comparatively evaluated, in terms of surface morphology, surface chemical composition, porosity, and storage modulus using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, micro-computed tomography, and dynamic mechanical analysis, respectively. The responses of chondrocytes cultured on individual PGS scaffolds were assessed, in terms of cell proliferation and ECM production. The results revealed that average pore sizes and porosity of the scaffolds were increased with an increasing sebacic acid concentration used. The storage moduli of the scaffolds were raised after the plasma treatment, possibly due to the further crosslinking of PGS upon treatment. Moreover, the scaffold prepared with a higher sebacic acid content demonstrated a greater capability of promoting cell infiltration, proliferation, and ECM production, especially when it was plasma-treated; the greatest HA, sGAG, uronic acid, and collagen contents were detected in matrix of this scaffold. The H & E and safranin O staining results also strongly supported this finding. The storage modulus of the scaffold was intensified after incubation with the chondrocytes for 21 days, indicating the accretion and retention of matrix ECM on the cell-cultured scaffold.