Aminoglycoside antibiotics, due to their strong antibacterial effects and broad antimicrobial spectra, have been very commonly used in clinical practice in the past half century. However, aminoglycoside antibiotics manifest severe ototoxicity and nephrotoxicity, and are one of top factors in hearing loss. In this study, three members of the aminoglycoside antibiotics family, gentamycin, neomycin and streptomycin, were chosen as the representatives to be investigated for their toxicity to the embryonic development and the larva hair cells in zebrafish, and also to their target genes associated with hearing-related genes. The results showed that: (1) the lethal effect of all three drugs demonstrated a significant dependence on concentration, and the severity order of the lethal effect was streptomycin > neomycin > gentamycin; (2) all the three drugs caused the larva trunk bending in resting state at 5 dpf (day past fertilization), probably due to their ototoxicity in the physical imbalance and postural abnormalities; (3) impairment and reducing of the hair cells were observed in all three cases of drug treatment; (4) four genes, eya1, val, otx2 and dlx6a, which play an important role in the development of hearing organs, showed differential and significant decrease of gene expression in a drug concentration-dependent manner. This study for the first time reports the relevance between the expression of hearing genes and the three ototoxic antibiotics and also proved the feasibility of establishing a simple, accurate, intuitive and fast model with zebrafish for the detection of drug ototoxicity.
Aminoglycosides ; toxicity ; Animals ; Anti-Bacterial Agents ; toxicity ; Embryonic Development ; drug effects ; Gene Expression Regulation ; Gentamicins ; toxicity ; Hair Cells, Auditory ; cytology ; drug effects ; Hearing Disorders ; chemically induced ; genetics ; metabolism ; Homeodomain Proteins ; metabolism ; Intracellular Signaling Peptides and Proteins ; metabolism ; Larva ; drug effects ; Lateral Line System ; drug effects ; MafB Transcription Factor ; metabolism ; Models, Animal ; Neomycin ; toxicity ; Nerve Tissue Proteins ; metabolism ; Nuclear Proteins ; metabolism ; Otx Transcription Factors ; metabolism ; Protein Synthesis Inhibitors ; toxicity ; Protein Tyrosine Phosphatases ; metabolism ; Streptomycin ; toxicity ; Zebrafish ; embryology ; Zebrafish Proteins ; metabolism

Orthodenticlehomeobox 1 (OTX1) overexpression had previously been associated with the progression of several tumors. The present study aimed to determine the expression and role of OTX1 in human hepatocellular carcinoma (HCC). The expression level of OTX1 was examined by quantitative real-time PCR (qRT-PCR) in 10 samples of HCC and paired adjacent non-cancerous tissues, and by immunohistochemistry (IHC) analysis in 128 HCC samples and matched controls. The relationship between OTX1 expression and the clinicopathological features werealso analyzed. Furthermore, the effects of OTX1 knockdown on cell proliferation and migration were determined in HCC cell lines. Axenograft mouse model was also established to investigate the role of OTX1 in HCC tumor growth. TheqRT-PCR and IHC analyses revealed that OTX1 was significantly elevated in HCC tissues compared with the paired non-cancerous controls. Expression of OTX1 was positively correlated with nodal metastasis status (P = 0.009) and TNM staging (P = 0.001) in HCC tissues. In addition, knockdown of OTX1 by shRNA significantly inhibited the proliferation and migration, and induced cell cycle arrest in S phase in vitro. Tumor growth was markedly inhibited by OTX1 silencing in the xenograft. Moreover, OTX1 silencing was causable for the decreased phosphorylation level of ERK/MAPK signaling. In conclusion, OTX1 contributes to HCC progression possibly by regulation of ERK/MAPK pathway. OTX1 may be a novel target for molecular therapy towards HCC.
Aged ; Animals ; Blotting, Western ; Carcinoma, Hepatocellular/metabolism/*pathology ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Disease Progression ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Immunohistochemistry ; Liver/metabolism/pathology ; Liver Neoplasms/metabolism/*pathology ; Lymphatic Metastasis ; MAP Kinase Signaling System ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Middle Aged ; Neoplasm Staging ; Otx Transcription Factors/antagonists & inhibitors/genetics/*metabolism ; Phosphorylation ; RNA Interference ; Real-Time Polymerase Chain Reaction ; S Phase Cell Cycle Checkpoints ; Transplantation, Heterologous