Disruption of circadian rhythm is believed to play a critical role in cancer development. To gain further insights into the roles of circadian genes in chronic myeloid leukemia (CML), we analyzed peripheral blood from 53 healthy individuals and 35 CML patients for the expression of the nine circadian genes. The expression levels of hPER1, hPER2, hPER3, hCRY1, hCRY2 and hBMAL1 were significantly impaired in both chronic phase and blastic crisis of CML cases compared with those in healthy individuals (P < 0.001). Methylation studies in the promoter areas of these six genes revealed that only the CpG sites of the hPER3 gene were methylated in all of the CML patients, and the methylated CpG frequencies differed significantly in patients at blastic crisis (8.24 ± 0.73) or at chronic phase (4.48 ± 0.48). The CpG sites of the hPER2 gene were also methylated in 40% of the CML patients. No mutation was found within the coding region of hPER3 in CML cases. Our results suggest that the downregulated hPER3 expression in CML is correlated with the inactivation of hPER3 by methylation. (Cancer Sci 2006; 97: 1298–1307)

Background: Gastric cancer (GC), an aggressive malignant tumor of the alimentary tract, is a leading cause of cancer-related death. Circadian rhythm exhibits a 24-hour variation in physiological processes and behavior, such as hormone levels, metabolism, gene expression, sleep and wakefulness, and appetite. Disruption of circadian rhythm has been associated with various cancers, including chronic myeloid leukemia, head and neck squamous cell carcinoma, hepatocellular carcinoma, endometrial carcinoma, and breast cancer. However, the expression of circadian clock genes in GC remains unexplored. Methods: In this study, the expression profiles of eight circadian clock genes (PER1, PER2, PER3, CRY1, CRY2, CKIϵ, CLOCK, and BMAL1) of cancerous and noncancerous tissues from 29 GC patients were investigated using real-time quantitative reverse-transcriptase polymerase chain reaction and validated through immunohistochemical analysis. Results: We found that PER2 was significantly up-regulated in cancer tissues (p < 0.005). Up-regulated CRY1 expression was significantly correlated with more advanced stages (stage III and IV) (p < 0.05). Conclusions: Our results suggest deregulated expressions of circadian clock genes exist in GC and circadian rhythm disturbance may be associated with the development of GC.

Mammalian target of rapamycin (mTOR) inhibitors, such as sirolimus and its derivative, everolimus, are potent immunosuppressive and antiproliferative drugs. Inflammatory diseases are characterized by immunological dysfunction, and monocyte recruitment underlies the mechanism of cell damage. Chemokines attract inflammatory cells to sites of inflammation. Interleukin-8 (IL-8/CXCL8); the monocyte chemoattractant protein-1 (MCP-1/CCL2); the regulated on activation, normal T cell expressed, presumably secreted protein (RANTES/CCL5); the macrophage inflammatory protein (MIP)-1α (CCL3); and MIP-1β (CCL4) are involved in the pathogenesis of inflammation. However, whether mTOR inhibitors moderate the production of chemokines in monocytes remains unclear. A human monocyte cell line, THP-1, and primary monocytes obtained from human volunteers, were stimulated using lipopolysaccharide (LPS), and then treated with sirolimus. The expression of the MCP-1, RANTES, IL-8, MIP-1α, MIP-1β, and TNF-α proteins was measured using enzyme-linked immunosorbent assays, and intracellular signalling was examined using western blotting. Sirolimus significantly suppressed the LPS-induced expression of MCP-1, IL-8, RANTES, MIP-1α, and MIP-1β in the THP-1 cells and human primary monocytes. The mitogen-activated protein kinase (MAPK) inhibitors that were examined suppressed the LPS-induced expression of MCP-1, IL-8, RANTES, MIP-1α, and MIP-1β. In addition, sirolimus suppressed the LPS-induced phosphorylation of p38 and p65 in the THP-1 and human primary monocytes. Sirolimus downregulates the expression of chemokines in monocytes, including MCP-1, RANTES, IL-8, MIP-1α, and MIP-1β, by inhibiting the NF-κB-p65 and MAPK-p38 signalling pathways.

Calcineurin inhibitors (CNIs) exhibit remarkable efficacy in atopic dermatitis (AD). Tacrolimus, one type of CNI, is prevalently used to treat AD. AD is a chronic inflammatory disease that exhibits predominant infiltration of T-helper type 2 (Th2) cell in the acute phase and a mixed Th1 and Th0 cell pattern in chronic lesions. Cytokines such as tumor necrosis factor-α (TNF-α), Th2-related chemokines [e.g., macrophage-derived chemokine (MDC)/CCL22 and I-309/CCL1], Th1-related chemokines [e.g., interferon γ-induced protein 10 (IP-10)/CXCL10], and neutrophil chemoattractant growth-related oncogene-α (GRO-α)/CXCL1 are involved in the pathogenesis of AD. However, whether tacrolimus modulates the expression of AD-associated cytokines and chemokines remains unknown. The intracellular mechanisms of tacrolimus are also unclear. Human monocytic cell line THP-1 cells were pretreated with tacrolimus and stimulated with lipopolysaccharide (LPS). The MDC, I-309, IP-10, GRO-α, and TNF-α concentrations of the cell supernatants were measured using enzyme-linked immunosorbent assay. Intracellular signaling was investigated using the Western blot analysis. Tacrolimus suppressed the expression of MDC, IP-10, I-309, GRO-α, and TNF-α in LPS-stimulated THP-1 cells in a dose- and time-dependent manner. All three mitogen-activated protein kinase (MAPK) inhibitors and the nuclear factor-κB inhibitor suppressed LPS-induced MDC, I-309, and TNF-α expressions in THP-1 cells. Only MAPK inhibitors suppressed LPS-induced expression of IP-10 and GRO-α. Tacrolimus suppressed the LPS-induced phosphorylation of MAPK-extracellular signal-related kinase (ERK). Tacrolimus suppressed LPS-induced MDC, I-309, IP-10, GRO-α, and TNF-α expressions in monocytes through the MAPK-ERK pathway; thus, tacrolimus may yield therapeutic efficacy by modulating AD-associated cytokines and chemokines.

Cisplatin‐induced acute kidney injury (AKI) is a major concern among clinicians in prescribing cisplatin‐based chemotherapy. This study evaluated and compared the ability of urinary biomarkers, including urinary neutrophil gelatinase‐associated lipocalin (NGAL), cystatin C, and the urinary albumin to creatinine ratio (ACR) to predict cisplatin‐induced AKI. Thirty‐three cancer patients receiving cisplatin‐based chemotherapy were prospectively studied, including 10 (30%) who developed AKI (the study group). Changes of urinary biomarkers were compared at 4 hours, 8 hours, and 12 hours, and 1 day, 2 days, 3 days, and 4 days after cisplatin intravenous infusions (75 mg/m²) versus the baseline. There was a significant increase in urinary NGAL levels from 12 hours to 4 days (p < 0.05) compared to baseline after cisplatin infusion in the AKI group. The magnitude of these changes over time differed significantly by group (p < 0.001). The area under the receiver operating curve describing the relationship between urinary NGAL levels and AKI within 12 hours was 0.865 (95% confidence interval = 0.691–1.000). Urinary NGAL levels independently predicted AKI 12 hours after cisplatin (p = 0.045) after adjustments for age, gender, body mass index, baseline serum creatinine, and urinary total protein. Urinary NGAL levels may be an early biomarker of AKI in patients receiving cisplatin‐based treatment.