Multicargo-loaded inverse opal gelatin hydrogel microparticles for promoting bacteria-infected wound healing.

Nowadays, many strategies have been developed to design biomaterials to accelerate bacteria-infected wound healing. Here, we presented a new type of multicargo-loaded inverse opal hydrogel microparticle (IOHM) for regulating oxidative stress, antibiosis, and angiogenesis of the bacteria-infected wound. The methacrylate acylated gelatin (GelMA)-based inverse opal hydrogel microparticles (IOHMs) were obtained by using the colloidal crystal microparticles as templates, and fullerol, silver nanoparticles (Ag NPs), and vascular endothelial growth factor (VEGF) were loaded in IOHMs. The developed multicargo-loaded IOHMs displayed good size distribution and biocompatibility, and when they were applied in cell culture, bacteria culture, and animal experiments, they exhibited excellent anti-oxidative stress properties, antibacterial properties, and angiogenesis. These characteristics of the developed multicargo-loaded IOHMs make them ideal for bacteria-infected wound healing.

An ultra-sensitive platinized nanocavity electrode for analysis of cytosolic catecholamines in one living cell.

The catecholamines, mainly dopamine (DA), are present in the cellular cytosol with low abundance, while, play key roles in various neurodegenerative disorders. Here, platinized nanocavity carbon electrodes are employed to analyze cytosolic catecholamines in a single living PC12 cell, which is not easily quantified using the classic electrodes. The confined structure and excellent conductivity in the platinized nanocavity accelerate the electron transfer of the DA, resulting in a low detection limit down to 50 nM. The sensitivity of DA detection is improved to be 10.73 pA mM-1 nm-1 in the response range of 50 nM-100 µM, which guarantees quantitative analysis of cytosolic catecholamines with low abundance. Eventually, the platinized nanocavity electrode is employed to detect cytosolic catecholamines in a single PC12 cell without an obvious interruption of cellular catecholamine level. The cytosolic catecholamines in a single PC12 cell is measured in situ to be 0.1 µM, which is achieved for the first time at the single cell level using the electrochemical method. The results demonstrate that the nanocavity electrode with a high sensitivity could offer a promising means to dynamically track catecholamines in a single cell.

Higher Baseline Serum Myokine of FSTL1 May Serve as a Potential Predictive Biomarker for Successful Brace Treatment in Girls With Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A retrospective case-control study. OBJECTIVE: This study aimed to investigate whether myokine, which is related to exercise and muscle mass, could serve as a biomarker for predicting bracing outcomes. SUMMARY OF BACKGROUND DATA: Several risk factors have been documented to be associated with bracing failure in patients with adolescent idiopathic scoliosis (AIS). However, serum biomarkers have not been extensively explored. PATIENTS AND METHODS: Skeletally immature females with AIS, without previous histories of bracing or surgery, were included. Peripheral blood was collected at the time of the bracing prescription. Baseline serum concentrations of 8 myokines [apelin, fractalkine, brain-derived neurotrophic factor, erythropoietin, osteonectin, fatty-acid-binding protein 3, follistatin-like 1 (FSTL1), and musclin] were measured by multiplex assays. Patients were followed up until weaned from bracing and then designated as a "failure" (defined as Cobb angle progression >5°) or "success." A logistic regression analysis was performed that accounted for serum myokines and skeletal maturity. RESULTS: We included 117 patients, with 27 in the failure group. Patients in the failure group had lower initial Risser sign and lower baseline serum levels of myokines, including FSTL1 (2217.3 ± 617.0 vs . 1369.3 ± 704.9, P = 0.002), apelin [116.5 (12.0, 335.9) vs . 83.5 (10.5, 221.1), P = 0.016], fractalkine (979.6 ± 457.8 vs . 743.8 ± 456.1, P = 0.020), and musclin [211.3 (16.3, 370.3) vs . 67.8 (15.5, 325.6), P = 0.049]. Following adjusted analysis, serum FSTL1 [odds ratio = 10.460; (2.213-49.453)] was determined to be predictive of bracing effectiveness. CONCLUSION: Patients who failed AIS bracing had significantly lower mean baseline levels of FSTL1 than those who achieved success. FSTL1 may serve as a biomarker that can inform outcomes after bracing.

Photosubstitution in a trisheteroleptic ruthenium complex inhibits conjunctival melanoma growth in a zebrafish orthotopic xenograft model.

In vivo data are rare but essential for establishing the clinical potential of ruthenium-based photoactivated chemotherapy (PACT) compounds, a new family of phototherapeutic drugs that are activated via ligand photosubstitution. Here a novel trisheteroleptic ruthenium complex [Ru(dpp)(bpy)(mtmp)](PF6)2 ([2](PF6)2, dpp = 4,7-diphenyl-1,10-phenanthroline, bpy = 2,2'-bipyridine, mtmp = 2-methylthiomethylpyridine) was synthesized and its light-activated anticancer properties were validated in cancer cell monolayers, 3D tumor spheroids, and in embryonic zebrafish cancer models. Upon green light irradiation, the non-toxic mtmp ligand is selectively cleaved off, thereby releasing a phototoxic ruthenium-based photoproduct capable notably of binding to nuclear DNA and triggering DNA damage and apoptosis within 24-48 h. In vitro, fifteen minutes of green light irradiation (21 mW cm-2, 19 J cm-2, 520 nm) were sufficient to generate high phototherapeutic indexes (PI) for this compound in a range of cancer cell lines including lung (A549), prostate (PC3Pro4), conjunctival melanoma (CRMM1, CRMM2, CM2005.1) and uveal melanoma (OMM1, OMM2.5, Mel270) cancer cell lines. The therapeutic potential of [2](PF6)2 was further evaluated in zebrafish embryo ectopic (PC3Pro4) or orthotopic (CRMM1, CRMM2) tumour models. The ectopic model consisted of red fluorescent PC3Pro4-mCherry cells injected intravenously (IV) into zebrafish, that formed perivascular metastatic lesions at the posterior ventral end of caudal hematopoietic tissue (CHT). By contrast, in the orthotopic model, CRMM1- and CRMM2-mCherry cells were injected behind the eye where they developed primary lesions. The maximally-tolerated dose (MTD) of [2](PF6)2 was first determined for three different modes of compound administration: (i) incubating the fish in prodrug-containing water (WA); (ii) injecting the prodrug intravenously (IV) into the fish; or (iii) injecting the prodrug retro-orbitally (RO) into the fish. To test the anticancer efficiency of [2](PF6)2, the embryos were treated 24 h after engraftment at the MTD. Optimally, four consecutive PACT treatments were performed on engrafted embryos using 60 min drug-to-light intervals and 90 min green light irradiation (21 mW cm-2, 114 J cm-2, 520 nm). Most importantly, this PACT protocol was not toxic to the zebrafish. In the ectopic prostate tumour models, where [2](PF6)2 showed the highest photoindex in vitro (PI > 31), the PACT treatment did not significantly diminish the growth of primary lesions, while in both conjunctival melanoma orthotopic tumour models, where [2](PF6)2 showed more modest photoindexes (PI ∼ 9), retro-orbitally administered PACT treatment significantly inhibited growth of the engrafted tumors. Overall, this study represents the first demonstration in zebrafish cancer models of the clinical potential of ruthenium-based PACT, here against conjunctival melanoma.

Galectin-3 Enhances Osteogenic Differentiation of Precursor Cells From Patients With Diffuse Idiopathic Skeletal Hyperostosis via Wnt/ß-Catenin Signaling.

Diffuse idiopathic skeletal hyperostosis (DISH) is a noninflammatory skeletal disease characterized by the progressive ectopic ossification and calcification of ligaments and enthuses. However, specific pathogenesis remains unknown. Bone marrow mesenchymal stem cells (BMSCs) are a major source of osteoblasts and play vital roles in bone metabolism and ectopic osteogenesis. However, it is unclear whether BMSCs are involved in ectopic calcification and ossification in DISH. The current study aimed to explore the osteogenic differentiation abilities of BMSCs from DISH patients (DISH-BMSCs). Our results showed that DISH-BMSCs exhibited stronger osteogenic differentiation abilities than normal control (NC)-BMSCs. Human cytokine array kit analysis showed significantly increased secretion of Galectin-3 in DISH-BMSCs. Furthermore, Galectin-3 downregulation inhibited the increased osteogenic differentiation ability of DISH-BMSCs, whereas exogenous Galectin-3 significantly enhanced the osteogenic differentiation ability of NC-BMSCs. Notably, the increased Galectin-3 in DISH-BMSCs enhanced the expression of ß-catenin as well as TCF-4, whereas attenuation of Wnt/ß-catenin signaling partially alleviated Galectin-3-induced osteogenic differentiation and activity in DISH-BMSCs. In addition, our results noted that Galectin-3 interacted with ß-catenin and enhanced its nuclear accumulation. Further in vivo studies showed that exogenous Galectin-3 enhanced ectopic bone formation in the Achilles tendon in trauma-induced rats by activating Wnt/ß-catenin signaling. The current study indicated that enhanced osteogenic differentiation of DISH-BMSCs was mainly attributed to the increased secretion of Galectin-3 by DISH-BMSCs, which enhanced ß-catenin expression and its nuclear accumulation. Our study helps illuminate the mechanisms of pathological osteogenesis and sheds light on the possible development of potential therapeutic strategies for DISH treatment. © 2022 American Society for Bone and Mineral Research (ASBMR).

TLD1433 Photosensitizer Inhibits Conjunctival Melanoma Cells in Zebrafish Ectopic and Orthotopic Tumour Models.

The ruthenium-based photosensitizer (PS) TLD1433 has completed a phase I clinical trial for photodynamic therapy (PDT) treatment of bladder cancer. Here, we investigated a possible repurposing of this drug for treatment of conjunctival melanoma (CM). CM is a rare but often deadly ocular cancer. The efficacy of TLD1433 was tested on several cell lines from CM (CRMM1, CRMM2 and CM2005), uveal melanoma (OMM1, OMM2.5, MEL270), epidermoid carcinoma (A431) and cutaneous melanoma (A375). Using 15 min green light irradiation (21 mW/cm2, 19 J.cm-2, 520 nm), the highest phototherapeutic index (PI) was reached in CM cells, with cell death occurring via apoptosis and necrosis. The therapeutic potential of TLD1433 was hence further validated in zebrafish ectopic and newly-developed orthotopic CM models. Fluorescent CRMM1 and CRMM2 cells were injected into the circulation of zebrafish (ectopic model) or behind the eye (orthotopic model) and 24 h later, the engrafted embryos were treated with the maximally-tolerated dose of TLD1433. The drug was administrated in three ways, either by (i) incubating the fish in drug-containing water (WA), or (ii) injecting the drug intravenously into the fish (IV), or (iii) injecting the drug retro-orbitally (RO) into the fish. Optimally, four consecutive PDT treatments were performed on engrafted embryos using 60 min drug-to-light intervals and 90 min green light irradiation (21 mW/cm2, 114 J.cm-2, 520 nm). This PDT protocol was not toxic to the fish. In the ectopic tumour model, both systemic administration by IV injection and RO injection of TLD1433 significantly inhibited growth of engrafted CRMM1 and CRMM2 cells. However, in the orthotopic model, tumour growth was only attenuated by localized RO injection of TLD1433. These data unequivocally prove that the zebrafish provides a fast vertebrate cancer model that can be used to test the administration regimen, host toxicity and anti-cancer efficacy of PDT drugs against CM. Based on our results, we suggest repurposing of TLD1433 for treatment of incurable CM and further testing in alternative pre-clinical models.

Light-Triggered Cancer Cell Specific Targeting and Liposomal Drug Delivery in a Zebrafish Xenograft Model.

Cell-specific drug delivery remains a major unmet challenge for cancer nanomedicines. Here, light-triggered, cell-specific delivery of liposome-encapsulated doxorubicin to xenograft human cancer cells in live zebrafish embryos is demonstrated. This method relies on light-triggered dePEGylation of liposome surfaces to reveal underlying targeting functionality. To demonstrate general applicability of this method, light-triggered, MDA-MB-231 breast cancer cell specific targeting in vivo (embryonic zebrafish) is shown using both clinically relevant, folate-liposomes, as well as an experimental liposome-cell fusion system. In the case of liposome-cell fusion, the delivery of liposomal doxorubicin direct to the cytosol of target cancer cells results in enhanced cytotoxicity, compared to doxorubicin delivery via either folate-liposomes or free doxorubicin, as well as a significant reduction in xenograft cancer cell burden within the embryonic fish.

Electrospinning of PELA/PPY Fibrous Conduits: Promoting Peripheral Nerve Regeneration in Rats by Self-Originated Electrical Stimulation.

Peripheral nerve injuries represent a great challenge for surgeons. The conductive neural scaffold has experienced increasing interest because of its good biocompatibility and similar electrical properties as compared to those of a normal nerve. Herein, nerve conduits made from poly(d,l-lactide)-co-poly(ethylene glycol) and polypyrrole (20%, 30%, and 50%) (PELA-PPY) were prepared by electrospinning, and used in regeneration of peripheral nerve defects. The results of an in vitro experiment indicated a high biocompatibility for the as-prepared materials, supporting the attachment and proliferation of a rat pheochromocytoma PC-12 cell. Furthermore, the PELA-PPY nerve conduit implanted in the sciatic nerve defects (10 mm) of the Spraguee-Dawley rats for 12 weeks showed similar results with the autograft, while it demonstrated a better outcome than the PELA nerve conduit in electrophysiological examination, sciatic function index, total amount of regenerated myelinated nerve fibers, axon diameter, myelin thickness, and several immunohistochemistry indices (S-100, laminin, neurofilament, bromodeoxyuridine, and glial fibrillary acidic portein). We supposed that the bioactivity is mainly generated by the PPY in composite nanofibers which could transmit self-originated electrical stimulation between cells. Due to the facile preparation and excellent in vivo performance, the PPY-PELA nerve conduit is promising for use as a bioengineered biomaterial for peripheral nerve regeneration.

The importance of Src signaling in sarcoma.

Src is a tyrosine kinase that is of significance in tumor biology. The present review focuses on Src, its molecular structure, and role in cancer, in addition to its expression and function in sarcoma. In addition, the feasibility of Src as a potential drug target for the treatment of sarcoma is also discussed. Previous studies have suggested that Src has essential functions in cell proliferation, apoptosis, invasion, metastasis and the tumor microenvironment. Thus, it may be a potential target for cancer therapy. Src has been found to enhance proliferation, reduce apoptosis and promote metastasis in certain subtypes of sarcoma, including osteosarcoma, chondrosarcoma and Ewing's sarcoma. Furthermore, a number of novel effective therapeutic agents, such as SI-83, which target Src have been investigated in vitro and in vivo. Bosutinib and dasatinib, which inhibit Src, have been approved by the U.S. Food and Drug Administration for the treatment of chronic myelogenous leukemia. In addition, vandetanib is approved for the treatment of medullary thyroid cancer. Furthermore, the Src inhibitor, saracatinib, is currently in clinical trials for the treatment of a variety of solid tumors, including breast and lung cancers. Thus, Src is considered to be an important factor in sarcoma progression and may present a novel clinical therapeutic target. This review demonstrates the importance and clinical relevance of Src in sarcoma, and discusses a number of small molecular inhibitors of src kinase, such as dasatinib and sarcatinib, which are currently in clinical trials for the treatment of sarcoma patients.

ABCB1 (rs1128503) polymorphism and response to chemotherapy in patients with malignant tumors-evidences from a meta-analysis.

Numerous papers have reported ABCB1 polymorphisms are associated with the response to chemotherapy of cancers. The inconclusive results call for a comprehensive analysis, for the sample size of the published studies is comparatively small. Therefore, a comprehensive meta-analysis was performed on the basis of the published studies for an accurate estimation of such association. Altogether 8 comparative studies including 2463 cancer patients were involved in our meta-analyses. ABCB1 C1236T (rs1128503) polymorphism was shown to be associated with tumor response to chemotherapy in cancer patients under the dominant model (OR=1.72, 95% CI=1.09-2.73, P=0.177, I(2)=36.60%) and additive model (OR=1.99, 95% CI=1.39-2.85, P=0.222, I(2)=25.90%). A subgroup meta-analysis indicated a significant association under dominant model between ABCB1 C1236T (rs1128503) polymorphism and breast cancer in the Asians (OR=2.15, 95% CI=1.22-3.77, P=0.210, I(2)=33.70%). These results suggest that ABCB1 C1236T (rs1128503) might contribute to the tumor response to chemotherapy in cancers from the Asians, especially in the osteosarcoma and breast cancer.

LEP and LEPR polymorphisms in non-Hodgkin lymphoma risk: a systematic review and pooled analysis.

PURPOSE: The purpose of this systematic meta-analysis was to evaluate the association between leptin (LEP) and leptin receptor (LEPR) gene polymorphisms and non-Hodgkin lymphoma (NHL) risk. METHODS: All studies published up to July 2014 on the association between LEP and LEPR polymorphisms and NHL risk were identified by searching PubMed, Web of Science, EMBASE, and Google Scholar. Odds ratios (ORs) with 95% confidence intervals (CIs) for LEP and LEPR polymorphisms and NHL were calculated with fixed-effects and random-effects models. RESULTS: LEP G2528A polymorphism was associated with increased, yet not statistically significant risk of NHL (homozygote comparison, OR=1.27, 95% CI=1.01-1.60, p=0.63; heterozygote comparison, OR=1.13, 95% CI=0.86-1.49, p=0.14; dominant model, OR=1.18, 95% CI=0.99-1.41, p=0.21; recessive model, OR=1.18, 95% CI=0.97-1.43, p=0.78; additive model, OR=1.14, 95% CI=1.01-1.28, p=0.52). Significant decrease of NHL risk was found in LEP A19G polymorphism, while no links were detected with the LEPR polymorphisms studied. In subgroup analysis, the pooled results showed that LEP A19G polymorphism was associated with decreased risk of follicular lymphoma (FL) (homozygote comparison, OR=0.56, 95% CI=0.37-0.85, p=0.69). However, no evidence of a significant association was observed in diffuse large B-cell lymphoma (DLBCL) for variant genotypes of all single nucleotide polymorphisms (SNPs). CONCLUSIONS: LEP G2548A polymorphism contributes to NHL susceptibility. Also, our results provide evidence that LEP A19G polymorphism is associated with decreased risk of NHL, especially in FL. Further large-scale and well-designed studies are needed to confirm this association.

Association of ABCB1/MDR1 polymorphisms in patients with glucocorticoid-induced osteonecrosis of the femoral head: Evidence for a meta-analysis.

PURPOSE: Glucocorticoid-induced osteonecrosis of the femoral head (GC-induced ONFH) is a rebarbative disease affecting people from all ages, especially young adults, and often leads to severe joint pain and limitations on physical activity. Numerous studies have reported that ABCB1 polymorphisms are associated with GC-induced ONFH, but the results are inconclusive, partially because the sample size of published studies is relatively small. Therefore, we performed a meta-analysis including seven case-control studies to estimate such association. METHODS: Published literature from Medline, Embase, and CNKI were searched for eligible publications. Pooled odds ratio (OR) together with their 95% confidence (CI) was calculated using a fixed effect model or random effect model. The meta-analysis was performed in accordance to PRISMA Statement Criteria. RESULTS: The ABCB1 3435T allele reduces the GC-induced ONFH risk based on the evidence from the co-dominant model (CT vs. CC, OR=0.73, 95% CI: 0.53-1.00; TT vs. CC, OR=0.43, 95% CI: 0.26-0.69), dominant model (CT+TT vs. CC, OR=0.64, 95% CI: 0.48-0.87), allele contract model, (T vs. C, OR=0.68, 95% CI: 0.54-0.84), and recessive model (TT vs. CC+CT, OR=0.52, 95% CI: 0.34-0.81). Similarly, the ABCB1 2677T/A allele reduce the GC-induced ONFH risk based on the evidence from the co-dominant model (GT/A vs. GG, OR=0.66, 95% CI: 0.45-0.96; T/AT/A vs. GG, OR=0.52, 95% CI: 0.34-0.82), dominant model (GT/A+T/AT/A vs. GG, OR=0.61, 95% CI: 0.43-0.87), and allele contract model (T/A vs. G, OR=0.73, 95% CI: 0.58-0.90). CONCLUSIONS: The meta-analysis revealed that 3435T allele and ABCB1 2677T/A allele may decrease the risks of GC-induced ONFH.

Monocyte chemotactic protein-1 promotes the proliferation and invasion of osteosarcoma cells and upregulates the expression of AKT.

Monocyte chemotactic protein­1 (MCP­1/CCL2) is an important immune factor, which may be important in cancer progression by promoting proliferation, invasion, metastasis and the tumor microenvironment. Previous studies have demonstrated that CCL2 affects the proliferation of osteosarcoma cells via the RANKL signaling pathway. However, the underlying mechanisms remain to be elucidated. To investigate the role of CCL2 in osteosarcoma cells, MTT, spheroid forming, wound healing and transwell assays were performed to examine the proliferation and invasion abilities of the osteosarcoma cells. It was revealed that the high-grade osteosarcoma cells exhibited increased expression levels of CCL2 compared with the low-grade osteosarcoma cells (P<0.001). Furthermore, knockdown of CCL2 decreased the proliferation and invasion abilities of the osteosarcoma cells (P<0.01). These results suggested that the expression of CCL2 is high in high-grade osteosarcoma cells and promotes the proliferation and invasion of osteosarcoma cells.

Association of the vascular endothelial growth factor -2578C/A polymorphism with cancer risk: A meta-analysis update.

The vascular endothelial growth factor (VEGF) -2578C/A polymorphism has been previously reported to be associated with cancer risk; however, the results have been controversial. Therefore, the aim of the present study was to explore the association between the VEGF -2578C/A polymorphism with the cancer risk. A total of 37 case-control studies were identified. The pooled analysis showed that there was no association between VEGF -2578C/A and the risk of cancer, and the odds ratios (ORs) [with the corresponding 95% confidence intervals (95% CIs)] were 0.97 (0.91-1.04) for C vs. A, 0.94 (0.86-1.02) for CC vs. AA, 0.92 (0.80-1.06) for CA vs. AA, 0.96 (0.89-1.03) for CC/CA vs. AA and 0.97 (0.88-1.08) for CC vs. CA/AA. Subgroup analyses according to ethnicity, source of control and type of cancer showed that the VEGF -2578C/A polymorphism is associated with colorectal and lung cancers. Additionally, the polymorphism may decrease the risk of cancer in the Asian population. This VEGF polymorphism was not associated with a risk of cancer for the Caucasian [0.92 (0.76-1.11) for CC vs. AA] and African populations [1.31 (0.67-2.58) for CC vs. AA], and it was not associated with bladder [1.06 (0.74-1.53) for CC/AA] and breast cancers [1.01 (0.90-1.15) for CC/AA]. Therefore, the present meta-analysis indicates that VEGF -2578C/A may only be associated with the risk of colorectal cancer, lung cancer and the Asian population. More studies with larger sample sizes are required to provide more conclusive evidence.

Lack of association between LEPR Lys656Asn or Ser343Ser polymorphisms and cancer susceptibility: A meta-analysis.

Previous studies have shown conflicting results between the association of leptin receptor (LEPR) genetic polymorphisms and cancer risk. The frequent LEPR Lys656Asn or Ser343Ser genetic polymorphism has been demonstrated to be functional and may promote genetic susceptibility to cancers. However, the association between the LEPR Lys656Asn or Ser343Ser genetic polymorphism and cancer risk remains to be determined. To improve the understanding of the LEPR Lys656Asn or Ser343Ser genetic polymorphism role in global cancer, a comprehensive meta-analysis was conducted that comprised 2,480 cases and 3,162 controls. The LEPR Lys656Asn or Ser343Ser genetic polymorphism did not significantly affect the cancer risk. In the stratified analysis, there was no significant association of the LEPR Lys656Asn or Ser343Ser variants with any type of cancer under any model. In addition, significantly increased risks were found in the Asian population in heterozygous codominant [odds ratio (OR), 1.24 (1.01-1.53)] and dominant [OR, 1.24 (1.02-1.50)] genetic models. A significantly increased susceptibility to cancer was not found when stratified by study design. There were no significant differences found in genotype method and sample size in cases among the genotypes. These findings indicated a lack of association between LEPR Lys656Asn or Ser343Ser polymorphisms and cancer susceptibility, however, these polymorphisms may increase the cancer susceptibility among the Asian population, particularly in the dominant genetic model. The single-nucleotide polymorphism is also suggested to function as a dominant mutation, which requires verification or association with functional studies.

miR-26a and its target CKS2 modulate cell growth and tumorigenesis of papillary thyroid carcinoma.

BACKGROUND: While many studies have shown that levels of miR-26a are lower in papillary thyroid carcinoma (PTC), the role and mechanism of miR-26a in PTC are unclear. METHOD: We used database searches to select potential mRNA targets of miR-26a. Anti-miR-26a, miR-26a mimic, siRNA for CKS2 and their effects on cell growth, cell-cycle distribution and colony formation were evaluated. We also evaluate the over-expressed miR-26a in TPC-1 cells in severe combined immune-deficient mice. We used luciferase reporter assays, real-time PCR and western blot analysis to measure the expression and activity of miR-26a, CKS2, and related factors such as cyclin B1, cyclin A, cdk1, bcl-xl and Akt. Finally, we measured the relationship between the levels of miR-26a and CKS2 in PTC and normal thyroid tissues. RESULTS: Relative to normal thyroid tissues, miR-26a is consistently down-regulated in TPC specimens, and CKS2 was identified as a potential target. Up-regulated miR-26a expression or down-regulated CKS2 expression in TPC-1 and CGTH W3 cells lines caused G2 phase-arrest. Decreased miR-26a expression or increased CKS2 expression could have inverse function on PTC cell lines. CyclinB1, cyclinA, bcl-xl and AKt are indirectly regulated by miR-26a in a CKS2-dependent manner. Finally, CKS2 is overexpressed in PTC specimens relative to normal thyroid tissue, and a significant inverse correlation exists between miR-26a and CKS2 expression in clinical PTC specimens. CONCLUSION: Our data indicate that miR-26a functions as a growth-suppressive miRNA in PTC, and that its suppressive effects are mediated mainly by repressing CKS2 expression.