The effects of melatonin and thymoquinone on doxorubicin-induced cardiotoxicity in rats.

OBJECTIVES: This study aims to investigate the protective effects of thymoquinone and melatonin on the heart against doxorubicin-induced cardiotoxicity in rats. BACKGROUND: Melatonin and thymoquinone may play an important role in cardiotoxicity. METHODS: The subjects were divided into four groups: Control (physiological serum on 5th day), Doxorubicin (DXR), Doxorubicin+Melatonin (DXR+MEL, 10 mg/kg melatonin, intraperitoneally), and Doxorubicin+Thymoquinone (DXR+TQ, 50 mg/kg thymoquinone, orally). On the 5th day of the experiment, all groups were injected with 45 mg/kg DXR into the tail vein. On the 8th day of the experiment, ECG recordings were performed under anaesthesia. RESULTS: Thymoquinone reduced the PR, QRS and QTc intervals, which were increased by DXR, while melatonin only reduced the QTc interval. Melatonin had a protective effect against the histopathological changes induced by DXR, while TQ did not demonstrate such an effect. DXR increased CK-MB, IL-6, MDA, IL-1, IL-18 levels and decreased SOD in the cardiac tissue. MEL reduced the levels of CK-MB, MDA, NO, SOD, IL-1, IL-6, IL-18. Meanwhile, TQ only reduced CK-MB, IL-1 and IL-18. CONCLUSION: Our study showed that DXR induces cardiac injury and that melatonin improves biochemical parameters and offers histological protection; while thymoquinone improves ECG parameters and causes partial recovery of biochemical parameters (Tab. 4, Fig. 2, Ref. 41).

Evidence for disease penetrance relating to CNV size: Pelizaeus-Merzbacher disease and manifesting carriers with a familial 11 Mb duplication at Xq22.

The potential causes for the incomplete penetrance of Pelizaeus-Merzbacher disease (PMD) in female carriers of PLP1 mutations are not well understood. We present a family with a boy having PMD in association with PLP1 duplication and three females who are apparent manifesting carriers. Custom high-resolution oligonucleotide array comparative genomic hybridization (aCGH) and breakpoint junction sequencing were performed and revealed a familial complex duplication consisting of a small duplicated genomic interval (∼56 kb) and a large segmental duplication (∼11 Mb) that resulted in a PLP1 copy number variation gain. Breakpoint junction analysis implicates a replication-based mechanism underlying the rearrangement formation. X-inactivation studies (XCI) showed a random to moderate advantageous skewing pattern in peripheral blood cells but a moderate to extremely skewed (≥90%) pattern in buccal cells. In conclusion, our data show that complex duplications involving PLP1 are not uncommon, can be detected at the level of genome resolution afforded by clinical aCGH and duplication and inversion can be produced in the same event. Furthermore, the observation of three manifesting carriers with a large genomic rearrangement supports the contention that duplication size along with genomic content can be an important factor for penetrance of the PMD phenotype in females.

Deletion mapping of chromosome 4q22-35 and identification of four frequently deleted regions in head and neck cancers.

Head and neck squamous cell carcinoma (HNSCC) is a diverse group of cancers that are frequently aggressive in their biologic behavior. Inactivation of tumor suppressor gene (TSG) is one of the most critical steps leading to HNSCC. Loss of heterozygosity analysis is very sensitive method for the detection of frequent allelic loss in a chromosomal locus. This method has been considered as an important evidence for the localization of TSGs. We analyzed loss of heterozygosity (LOH) at chromosome 4q22-35 region by using 14 polymorphic microsatellite markers in 83 matched normal and HNSCC tissues. LOH was detected at least in one location in 71 of 83 (86%) tumor tissues. Frequent deletions were detected at the location of microsatellite markers, D4S2909 (46%), D4S2623 (51%), D4S406 (48%), D4S1644 (45%) and D4S2979 (40%). Four different frequently deleted regions at 4q22, 4q25, 4q31 and 4q34-35 were observed. These regions include several putative TSGs such as Caspase-6, SMARCAD1, SMARCA5, SAP30 and ING2. Further molecular analysis of each gene should be performed to clarify their roles in head and neck squamous cell carcinogenesis.