Curcumin-Based Nanoformulations: A Promising Adjuvant towards Cancer Treatment.

Throughout the United States, cancer remains the second leading cause of death. Traditional treatments induce significant medical toxic effects and unpleasant adverse reactions, making them inappropriate for long-term use. Consequently, anticancer-drug resistance and relapse are frequent in certain situations. Thus, there is an urgent necessity to find effective antitumor medications that are specific and have few adverse consequences. Curcumin is a polyphenol derivative found in the turmeric plant (Curcuma longa L.), and provides chemopreventive, antitumor, chemo-, and radio-sensitizing properties. In this paper, we summarize the new nano-based formulations of polyphenolic curcumin because of the growing interest in its application against cancers and tumors. According to recent studies, the use of nanoparticles can overcome the hydrophobic nature of curcumin, as well as improving its stability and cellular bioavailability in vitro and in vivo. Several strategies for nanocurcumin production have been developed, each with its own set of advantages and unique features. Because the majority of the curcumin-based nanoformulation evidence is still in the conceptual stage, there are still numerous issues impeding the provision of nanocurcumin as a possible therapeutic option. To support the science, further work is necessary to develop curcumin as a viable anti-cancer adjuvant. In this review, we cover the various curcumin nanoformulations and nanocurcumin implications for therapeutic uses for cancer, as well as the current state of clinical studies and patents. We further address the knowledge gaps and future research orientations required to develop curcumin as a feasible treatment candidate.

Expression of Desmoglein 2, Desmocollin 3 and Plakophilin 2 in Placenta and Bone Marrow-Derived Mesenchymal Stromal Cells.

Many controversial results exist when comparing mesenchymal stromal cells (MSCs) derived from different sources. Reasons include not only variables in tissue origin, but also methods of cell preparation or choice of expansion media which can strongly influence the expression and hence, function of the cells. In this short report we aimed to investigate the expression of the cell anchoring proteins desmoglein 2, desmocollin 3 and plakophilin 2 in early passage placenta-derived MSCs of fetal (fetal pMSCs) and maternal (maternal pMSCs) origins versus adult bone marrow-derived MSCs (bmMSCs) that were expanded and cultured under the same good manufacturing practice (GMP) conditions. Comprehensive gene expression microarray analysis profiling indicated differential expression of these genes in the different MSC-derived types with fetal pMSCs expressing the highest levels of PKP2, DSC3 and DSG2, followed by maternal pMSCs, while bmMSCs expressed the lowest levels. A higher expression of PKP2 and DSC3 genes in fetal pMSCs was confirmed by qRT-PCR suggesting neonatal increases in the expression of these desmosomal genes vs. adult MSCs. Intracellular desmocollin 3 and desmoglein 2 expression was observed by flow cytometry and cytoplasmic plakophilin 2 by immunofluorescence in all three MSC sources. These data suggest that fetal pMSCs, maternal pMSCs and bmMSCs may anchor intermediate filaments to the plasma membrane via desmocollin 3, desmoglein 2 and plakophilin 2.

Bone marrow-derived mesenchymal stromal cells differ in their attachment to fibronectin-derived peptides from term placenta-derived mesenchymal stromal cells.

INTRODUCTION: Human mesenchymal stromal cells (MSCs) can be isolated from different sources including bone marrow and term placenta. These two populations display distinct patterns of proliferation and differentiation in vitro. Since proliferation and differentiation of cells are modulated by cell-matrix interactions, we investigated the attachment of MSCs to a set of peptide-coated surfaces and explored their interactions with peptides in suspension. METHODS: Human MSCs were isolated from bone marrow and term placenta and expanded. Binding of MSCs to peptides was investigated by a cell-attachment spot assay, by blocking experiments and flow cytometry. The integrin expression pattern was explored by a transcript array and corroborated by quantitative reverse transcription polymerase chain reaction and flow cytometry. RESULTS: Expanded placenta-derived MSCs (pMSCs) attached well to surfaces coated with fibronectin-derived peptides P7, P15, and P17, whereas bone marrow-derived MSCs (bmMSCs) attached to P7, but barely to P15 and P17. The binding of bmMSCs and pMSCs to the peptides was mediated by ß1 integrins. In suspension, expanded bmMSCs barely bind to P7, P13, P15, and less to P14 and P17. Ex vivo, bmMSCs failed to bind P7, but displayed a weak interaction with P13, P14, and P15. In suspension, expanded pMSCs displayed binding to many peptides, including P4, P7, P13, P14, P15, and P17. The differences observed in binding of bmMSCs and pMSCs to the peptides were associated with significant differences in expression of integrin α2-, α4-, and α6-chains. CONCLUSIONS: Human bmMSCs and pMSCs show distinct patterns of attachment to defined peptides and maintain differences in expression of integrins in vitro. Interactions of ex vivo bmMSCs with a given peptide yield different staining patterns compared to expanded bmMSCs in suspension. Attachment of expanded MSCs to peptides on surfaces is different from interactions of expanded MSCs with peptides in suspension. Studies designed to investigate the interactions of human MSCs with peptide-augmented scaffolds or peptides in suspension must therefore regard these differences in cell-peptide interactions.

A novel point mutation promotes growth phase-dependent daptomycin tolerance in Staphylococcus aureus.

Recalcitrance of genetically susceptible bacteria to antibiotic killing is a hallmark of bacterial drug tolerance. This phenomenon is prevalent in biofilms, persisters, and also planktonic cells and is associated with chronic or relapsing infections with pathogens such as Staphylococcus aureus. Here we report the in vitro evolution of an S. aureus strain that exhibits a high degree of nonsusceptibility to daptomycin as a result of cyclic challenges with bactericidal concentrations of the drug. This phenotype was attributed to stationary growth phase-dependent drug tolerance and was clearly distinguished from resistance. The underlying genetic basis was revealed to be an adaptive point mutation in the putative inorganic phosphate (Pi) transporter gene pitA. Drug tolerance caused by this allele, termed pitA6, was abrogated when the upstream gene pitR was inactivated. Enhanced tolerance toward daptomycin, as well as the acyldepsipeptide antibiotic ADEP4 and various combinations of other drugs, was accompanied by elevated intracellular concentrations of Pi and polyphosphate, which may reversibly interfere with critical cellular functions. The evolved strain displayed increased rates of survival within human endothelial cells, demonstrating the correlation of intracellular persistence and drug tolerance. These findings will be useful for further investigations of S. aureus drug tolerance, toward the development of additional antipersister compounds and strategies.

Insight into the evolution and origin of leprosy bacilli from the genome sequence of Mycobacterium lepromatosis.

Mycobacterium lepromatosis is an uncultured human pathogen associated with diffuse lepromatous leprosy and a reactional state known as Lucio's phenomenon. By using deep sequencing with and without DNA enrichment, we obtained the near-complete genome sequence of M. lepromatosis present in a skin biopsy from a Mexican patient, and compared it with that of Mycobacterium leprae, which has undergone extensive reductive evolution. The genomes display extensive synteny and are similar in size (∼3.27 Mb). Protein-coding genes share 93% nucleotide sequence identity, whereas pseudogenes are only 82% identical. The events that led to pseudogenization of 50% of the genome likely occurred before divergence from their most recent common ancestor (MRCA), and both M. lepromatosis and M. leprae have since accumulated new pseudogenes or acquired specific deletions. Functional comparisons suggest that M. lepromatosis has lost several enzymes required for amino acid synthesis whereas M. leprae has a defective heme pathway. M. lepromatosis has retained all functions required to infect the Schwann cells of the peripheral nervous system and therefore may also be neuropathogenic. A phylogeographic survey of 227 leprosy biopsies by differential PCR revealed that 221 contained M. leprae whereas only six, all from Mexico, harbored M. lepromatosis. Phylogenetic comparisons indicate that M. lepromatosis is closer than M. leprae to the MRCA, and a Bayesian dating analysis suggests that they diverged from their MRCA approximately 13.9 Mya. Thus, despite their ancient separation, the two leprosy bacilli are remarkably conserved and still cause similar pathologic conditions.

Altering gene expression by aminocoumarins: the role of DNA supercoiling in Staphylococcus aureus.

BACKGROUND: It has been shown previously that aminocoumarin antibiotics such as novobiocin lead to immediate downregulation of recA expression and thereby inhibit the SOS response, mutation frequency and recombination capacity in Staphylococcus aureus. Aminocoumarins function by inhibiting the ATPase activity of DNA gyrase subunit B with a severe impact on DNA supercoiling. RESULTS: Here, we have analysed the global impact of the DNA relaxing agent novobiocin on gene expression in S. aureus. Using a novobiocin-resistant mutant, it became evident that the change in recA expression is due to gyrase inhibition. Microarray analysis and northern blot hybridisation revealed that the expression levels of a distinct set of genes were increased (e.g., recF-gyrB-gyrA, the rib operon and the ure operon) or decreased (e.g., arlRS, recA, lukA, hlgC and fnbA) by novobiocin. The two-component ArlRS system was previously found to decrease the level of supercoiling in S. aureus. Thus, downregulation of arlRS might partially compensate for the relaxing effect of novobiocin. Global analysis and gene mapping of supercoiling-sensitive genes did not provide any indication that they are clustered in the genome. Promoter fusion assays confirmed that the responsiveness of a given gene is intrinsic to the promoter region but independent of the chromosomal location. CONCLUSIONS: The results indicate that the molecular properties of a given promoter, rather than the chromosomal topology, dictate the responsiveness to changes in supercoiling in the pathogen Staphylococcus aureus.

Low osteogenic differentiation potential of placenta-derived mesenchymal stromal cells correlates with low expression of the transcription factors Runx2 and Twist2.

Recent studies indicated that mesenchymal stromal cells from bone marrow (bmMSC) differ in their osteogenic differentiation capacity compared to MSC from term placenta (pMSC). We extended these studies and investigated the expression of factors involved in regulation of bone metabolism in both cell types. To this end, MSC were expanded in vitro and characterized. The total transcriptome was investigated by microarrays, and for selected genes, the differences in gene expression were explored by quantitative reverse transcriptase-polymerase chain reaction, immunocytochemistry, and flow cytometry. We report that bmMSC and pMSC share expression of typical lineage surface markers, including CD73, CD90, CD105, and lack of CD14, CD34, and CD45. However, according to transcriptome analyses, they differ significantly in their expression of more than 590 genes. Factors involved in bone metabolism, including alkaline phosphatase (P<0.05), osteoglycin (P<0.05), osteomodulin (P<0.05), runt-related transcription factor 2 (Runx2) (P<0.04), and WISP2 (P<0.05), were expressed at significantly lower levels in pMSC, but twist-related protein 2 (Twist2) (P<0.0002) was expressed at significantly higher levels. The osteogenic differentiation capacity of pMSC was very low. The adipogenic differentiation was somewhat more prominent in bmMSC, while the chondrogenic differentiation seemed not to differ between bmMSC and pMSC, as determined by histochemical staining. However, expression and induction of peroxisome proliferator-activated receptor gamma-2 (PPARγ2) and Sox9, factors involved in early adipogenesis and chondrogenesis, respectively, were higher in bmMSC. We conclude that despite many similarities between bmMSC and pMSC, when expanded under identical conditions, they vary considerably with respect to their in vitro differentiation potential. For regenerative purposes, the choice of MSC may therefore influence the outcome of a treatment considerably.

Phosphoglycerate kinase 1 promoting tumor progression and metastasis in gastric cancer - detected in a tumor mouse model using positron emission tomography/magnetic resonance imaging.

BACKGROUND/AIMS: Tumor dissemination is frequent in gastric cancer and implies a poor prognosis. Cure is only achievable provided an accurate staging is performed at primary diagnosis. In previous studies we were able to show a relevant impact of increased phosphoglycerate kinase 1 expression (PGK1; a glycolytic enzyme) on invasive properties of gastric cancer in-vivo and in-vitro. Thus the aim of the present study was to evaluate the effect of enhanced PGK1 expression in gastric cancer employing magnetic resonance (MR)-imaging combined with positron emission tomography (PET), a recently emerging new high resolution imaging technique in a mouse model. METHODS: A metastatic nude mouse model simulating human gastric cancer behavior by orthotopic tumor implantation was established. Mice were divided into one control group (n=5) and two experimental groups (n=30) divided by half in animals baring tumors from MKN45-cells and MKN45-cells with plasmid-mediated overexpression of PGK1. In the course of tumor growth MR-imaging and PET/MRI fusion was performed. Successively experimental animals were examined macroscopically and histopathologically regarding growth, metastasis and PGK1 expression. RESULTS: Elevated PGK1 expression increased invasive and metastatic behavior of implanted gastric tumors significantly. MR/PET- imaging results in-vivoand subsequent ex-vivo findings concerning tumor growth and metastasis correlated excellently and could be underlined by concordant immuohistochemical PGK1 staining. CONCLUSION: Consistent in-vivo findings suggest that PGK1 might be crucially involved in gastric malignancy regarding growth and metastasis, which was also underlined by novel imaging techniques. Thus, PGK1 may be exploited as a prognostic marker and/or be of potential therapeutic value preventing malignant dissemination.

Circadian expression of clock- and tumor suppressor genes in human oral mucosa.

PURPOSE: Circadian rhythms are daily oscillations of multiple biological processes driven by endogenous clocks. Imbalance of these rhythms has been associated with cancerogenesis in humans. To further elucidate the role circadian clocks have in cellular growth control, tumor suppression and cancer treatment, it is revealing to know how clock genes and clock-controlled genes are regulated in healthy humans. MATERIALS AND METHODS: Therefore comparative microarray analyses were conducted investigating the relative mRNA expression of clock genes throughout a 24-hour period in cell samples obtained from oral mucosa of eight healthy diurnally active male study participants. Differentially expressed selected genes of interest were additionally evaluated using qRT-PCR. RESULTS: Microarray analysis revealed 33 significant differentially regulated clock genes and clock- controlled genes, throughout a one day period (6.00h, 12.00h, 18.00h, 24.00h). Hereof were 16 clock genes and 17 clock- controlled genes including tumor suppressor- and oncogenes. qRT-PCR of selected genes of interest, such as hPER2, hCRY1, hBMAL1, hCCRN4L and hSMAD5 revealed significant circadian regulations. CONCLUSION: Our study revealed a proper circadian regulation profile of several clock- and tumor suppressor genes at defined points in time in the participants studied. These findings could provide important information regarding genes displaying the same expression profile in the gastrointestinal tract amounting to a physiological expression profile of healthy humans. In the future asynchronous regulations of those genes might be an additional assistant method to detect derivations distinguishing normal from malignant tissue or assessing risk factors for cancer.

Phosphoglycerate kinase 1 a promoting enzyme for peritoneal dissemination in gastric cancer.

Peritoneal carcinomatosis is a frequent finding in gastric cancer associated with a poor prognosis. The features that enable gastric tumors to disseminate are poorly understood until now. Previously, we showed elevated mRNA levels of phosphoglycerate kinase 1 (PGK1), an adenosine triphosphate-generating enzyme in the glycolytic pathway, the chemokine receptor 4 (CXCR4), the corresponding chemokine ligand 12 (CXCL12) and beta-catenin in specimens from gastric cancer patients with peritoneal carcinomatosis. In this study, the influence of PGK1 on CXCR4 and beta-catenin was assessed as well as the invasiveness of PGK1 overexpressing cancer cells. In this current study, we found that PGK1 regulates the expression of CXCR4 and beta-catenin at the mRNA and protein levels. On the other hand, CXCR4 regulates the expression of PGK1. Plasmid-mediated overexpression of PGK1 dramatically increased the invasiveness of gastric cancer cells. Interestingly, inhibition of CXCR4 in cells overexpressing PGK1 produced only a moderate reduction of invasiveness suggesting that, PGK1 itself has a critical role in tumor invasiveness. Immunohistochemistry in specimens from diffuse gastric cancer patients also revealed an overexpression of PGK1 in patients with development of peritoneal carcinomatosis. Therefore, PGK1 may be a crucial enzyme in peritoneal dissemination. Together these findings suggest that the enhanced expression of PGK1 and its signaling targets CXCR4 and beta-catenin in gastric cancer cells promote peritoneal carcinomatosis. Thus, PGK1 may serve as prognostic marker and/or be a potential therapeutic target to prevent dissemination of gastric carcinoma cells into the peritoneum.

(18)F-FDG-PET/CT to select patients with peritoneal carcinomatosis for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with significantly longer survival in patients with peritoneal carcinomatosis (PC). So far, no morphological imaging method has proven to accurately assess the intra-abdominal tumor spread. This study was designed to predict tumor load in patients with PC using dual-modality (18)FDG-PET/CT and to compare the results with those of PET and CT alone by correlating imaging findings with intraoperative staging. METHODS: Twenty-two patients with PC from gastrointestinal (n = 13), ovarian cancer (n = 8), and mesothelioma (n = 1) underwent contrast-enhanced (18)FDG-PET/CT before surgery and HIPEC. In a retrospective analysis PET, CT, and fused PET/CT were separately and blindly reviewed for the extent of peritoneal involvement using the Peritoneal Cancer Index (PCI). Imaging results were correlated with the intraoperative PCI using Pearson's correlation coefficient and linear regression analysis. RESULTS: There was a strong correlation between the PCI obtained with PET/CT and the surgical PCI with respect to the total score (r = 0.951) as well as in the regional analysis (small bowel, r = 0.838; other, r = 0.703). The correlation was slightly lower for CT alone (total score, r = 0.919; small bowel, r = 0.754; other, r = 0.666) and significantly lower (p = 0.002) for PET alone (total score, r = 0.793; small bowel, r = 0.553, other, 0.507). CONCLUSIONS: Contrast-enhanced CT is superior compared with PET alone to predict the extent of PC. In our patient group, the combination of both modalities (contrast enhanced PET/CT) yielded the best results and proved to be a useful tool for selecting candidates for peritonectomy and HIPEC.

PGK1 a potential marker for peritoneal dissemination in gastric cancer.

BACKGROUND/AIMS: Peritoneal carcinomatosis, which is caused by the dissemination of cancer cells into the abdominal cavity is a frequent finding in patients with primary gastric cancer, and it is associated with a poor prognosis. The mechanisms that mediate peritoneal carcinomatosis in diffuse primary gastric tumours require definition. METHODS: We therefore compared the gene expression profile in diffuse primary gastric cancer patients with and without peritoneal carcinomatosis (n=13). Human specimens from consecutive gastric cancer patients with and without peritoneal carcinomatosis were investigated using oligonucleotide microarrays. Differentially expressed genes of interest were further evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: The results reveal a significant overexpression of phosphoglycerate kinase 1 (PGK1), the chemokine CXCR4 and its ligand CXCL12 in specimens from diffuse gastric cancer patients with peritoneal carcinomatosis. Overexpression of PGK1 is known to increase the expression of CXCR4. CXCR4 on its part can increase CXCL12 expression. Elevated levels of CXCR4 and CXCL12 are associated with an increase in the metastatic rate and play an important role in the metastatic homing of malignant cells. CONCLUSION: The overexpression of PGK1 and its signalling targets may be a expression-pathway in diffuse primary gastric carcinomas promoting peritoneal dissemination and may function as prognostic markers and/or be potential therapeutic targets to prevent the migration of gastric carcinoma cells into the peritoneum.

Lactate modulates gene expression in human mesenchymal stem cells.

PURPOSE: Surgical wounds are characterised by elevated tissue lactate concentrations. This accumulated lactate is capable of stimulating collagen synthesis and new vessel growth as well. Recently, it has been shown in vivo that lactate is also able to favour homing of stem cells. The aim of this investigation was to test the hypothesis that lactate has an impact on gene expression of mesenchymal stem cells (MSC). MATERIALS AND METHODS: MSC were isolated from human bone marrow using the density gradient technique and incubated with alpha-methoxyethoxymethyl containing 10% fetal calf serum at 37 degrees C under 95% air and 5% CO(2). Cultured MSC were characterised by in vitro differentiation assays and fluorescence-activated cell sorting (FACS) analysis. Characterised MSC were treated with 15 mM lactate for different time periods (1, 6 and 24 h and 3 and 7 days). Gene expression analysis was performed using a custom-designed oligonucleotide microarray. A significant alteration of gene expression was defined as a two-fold stimulation or inhibition. The phenotype of MSC was investigated by FACS analysis of specific surface epitope patterns. RESULTS: Gene expression analysis shows 63 up- and 51 down-regulated genes after 1 h of treatment, 45 up- and 47 down-regulated genes after 6 h of treatment, 57 up- and 72 down-regulated genes after 24 h of treatment, 103 up- and 28 down-regulated genes after 3 days of treatment and 50 up- and 101 down-regulated genes after 7 days of treatment with lactate. The majority of the modulated genes are related to the expression of cytokines, transcription factors and cell-cycle- or cellular-matrix-associated proteins. In particular, lactate up-regulates the expression of interleukin-6 (3 days, 4.11-fold), of heat shock protein 70 (3 days, 2.36-fold) and of hypoxia-inducible factor-1alpha (3 days, 2.09-fold). A down-regulating effect of lactate is observed for superoxide dismutase 2 (1 h, 0.5-fold; 24 h, 0.4-fold; 7 days, 0.32-fold) and BCL2-associated X protein (24 h, 0.42-fold; 7 days, 0.4-fold). Expression of cell surface antigens clusters of differentiation 29, 44, 59, 73, 90, 105, 106 and 146 does not change over the time period of lactate treatment. CONCLUSIONS: Lactate modulates expression of genes involved in wound healing. However, lactate does not profoundly change the phenotype of MSC. In addition to providing new insights into the wound healing physiology, these data could also be the rationale for new treatment strategies for chronic non-healing wounds.

Chromatin modifications induced by PML-RARalpha repress critical targets in leukemogenesis as analyzed by ChIP-Chip.

The translocation t(15;17) generates the chimeric PML-RARalpha transcription factor that is the initiating event of acute promyelocytic leukemia. A global view of PML-RARalpha transcriptional functions was obtained by genome-wide binding and chromatin modification analyses combined with genome-wide expression data. Chromatin immunoprecipitation (ChIP)-chip experiments identified 372 direct genomic PML-RARalpha targets. A subset of these was confirmed in primary acute promyelocytic leukemia. Direct PML-RARalpha targets include regulators of global transcriptional programs as well as critical regulatory genes for basic cellular functions such as cell-cycle control and apoptosis. PML-RARalpha binding universally led to HDAC1 recruitment, loss of histone H3 acetylation, increased tri-methylation of histone H3 lysine 9, and unexpectedly increased trimethylation of histone H3 lysine 4. The binding of PML-RARalpha to target promoters and the resulting histone modifications resulted in mRNA repression of functionally relevant genes. Taken together, our results reveal that the transcription factor PML-RARalpha regulates key cancer-related genes and pathways by inducing a repressed chromatin formation on its direct genomic target genes.

Progression-specific genes identified by expression profiling of matched ductal carcinomas in situ and invasive breast tumors, combining laser capture microdissection and oligonucleotide microarray analysis.

Becoming invasive is a crucial step in breast cancer oncogenesis. At this point, a lesion carries the potential for spreading and metastasis--a process, whose molecular characteristics still remain poorly understood. In this article, we describe a matched-pair analysis of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of nine breast ductal carcinomas to identify novel molecular markers characterizing the transition from DCIS to IDC. The purpose of this study was to better understand the molecular biology of this transition and to identify candidate genes whose products might serve as prognostic markers and/or as molecular targets for treatment. To obtain cellular-based gene expression profiles from epithelial tumor cells, we combined laser capture microdissection with a T7-based two-round RNA amplification and Affymetrix oligonucleotide microarray analysis. Altogether, a set of 24 tumor samples was analyzed, comprised of nine matched DCIS/IDC and replicate DCIS/IDC preparations from three of the nine tumors. Cluster analysis on expression data shows the robustness and reproducibility of the techniques we established. Using multiple statistical methods, 546 significantly differentially expressed probe sets were identified. Eighteen candidate genes were evaluated by RT-PCR. Examples of genes already known to be associated with breast cancer invasion are BPAG1, LRRC15, MMP11, and PLAU. The expression of BPAG1, DACT1, GREM1, MEF2C, SART2, and TNFAIP6 was localized to epithelial tumor cells by in situ hybridization and/or immunohistochemistry, confirming the accuracy of laser capture microdissection sampling and microarray analysis.

cDNA microarray analysis reveals novel candidate genes expressed in human peripheral blood following exhaustive exercise.

It is generally accepted that exhausting endurance exercise exhibits strong effects on the immune system. Such effects have been attributed to changes in the cellular composition of peripheral blood as well as to changes in the expression of plausible candidate genes. The list of candidate genes is far from being complete, since this issue has not yet been investigated in a systematic way. In this study, we used a custom-made cDNA microarray focused on inflammation as a screening approach to study gene expression in eight one-half marathon runners before, immediately after, and 24 h after exercise. Significant differential gene expression was verified by quantitative real-time PCR. Linear regression analysis showed that microarray expression analysis of cell type-specific surface molecules reflects the observed individual cellular shifts in peripheral blood cells with high statistical significance. In line with the results of former studies, we observed an upregulation of mitogen-activated protein kinase-activated protein kinase-2 (MAPKAP-K2), L-selectin, and IL-1 receptor antagonist (IL-1ra) after exhaustive exercise. The main results of this study report, for the first time, the downregulation of CD81; the upregulation of thioredoxin, which may play an important part in anti-oxidative defense; and, surprisingly, the downregulation of the anti-carcinogenic gene glutathione-S-transferase-3 (GSTM3) in peripheral blood. The study shows cDNA microarray expression analysis as a reliable systematic instrument to complete the list of candidate genes that may play a role in exhaustive exercise-induced modulation of the immune response.