Oxaliplatin-Associated Amaurosis Fugax

Oxaliplatin-associated amaurosis fugax has not been reported, and its clinical course and treatment remain largely unclear. A 70-year-old man with advanced gastric cancer was treated with the SOX regimen. After cycle 1 of oxaliplatin infusion, the patient realized that his right eye had visual field impairment, which he described as darkening of the right half of his visual field and loss of vision lasting about 1 min and occurring about 7 times a day. The daily frequency of this occurrence gradually decreased, and his visual field impairment improved in 1 week. However, as the same symptoms recurred from cycle 2 to cycle 5 of treatment, oxaliplatin was discontinued from cycle 6 and switched to S-1 monotherapy. Subsequently, the patient’s amaurosis fugax improved. To our knowledge, this is the first report describing clinical course and treatment of oxaliplatin-associated amaurosis fugax

Oncogenic Ras-Induced Morphologic Change Is through MEK/ERK Signaling Pathway to Downregulate Stat3 at a Posttranslational Level in NIH3T3 Cells1

Ras is a key regulator of the MAP kinase-signaling cascade and may cause morphologic change of Ras-transformed cells. Signal transducer and activator of transcription 3 (Stat3) can be activated by cytokine stimulation. In this study, we unravel that Ha-rasV12 overexpression can downregulate the expression of Stat3 protein at a posttranslational level in NIH3T3 cells. Furthermore, we demonstrate that Stat3 expression downregulated by Ha-rasV12 overexpression is through proteosome degradation and not through a mTOR/p70S6K-related signaling pathway. The suppression of Stat3 accompanied by the morphologic change induced by Ha-rasV12 was through mitogen extracellular kinase (MEK)/extracellular-regulated kinase (ERK) signaling pathway. Microtubule disruption is involved in Ha-rasV12-induced morphologic change, which could be reversed by overexpression of Stat3. Taken together, we are the first to demonstrate that Stat3 protein plays a critical role in Ha-rasV12-induced morphologic change. Oncogenic Ras-triggered morphologic change is through the activation of MEK/ERK to posttranslationally downregulate Stat3 expression. Our finding may shed light on developing novel therapeutic strategies against Ras-related tumorigenesis