TGF-β1 Promotes Zika Virus Infection in Immortalized Human First-Trimester Trophoblasts via the Smad Pathway

The Zika virus (ZIKV) is well known for causing congenital Zika syndrome if the infection occurs during pregnancy; however, the mechanism by which the virus infects and crosses the placenta barrier has not been completely understood. In pregnancy, TGF-β1 is abundant at the maternal–fetal interface. TGF-β1 has been reported to enhance rubella virus binding and infection in human lung epithelial cells. Therefore, in this study, we investigate the role of TGF-β1 in ZIKV infection in the immortalized human first-trimester trophoblasts, i.e., Swan.71. The cells were treated with TGF-β1 (10 ng/mL) for two days before being inoculated with the virus (American strain PRVABC59) at a multiplicity of infection of five. The results showed an enhancement of ZIKV infection, as demonstrated by the immunofluorescent assay and flow cytometry analysis. Such enhanced infection effects were abolished using SB431542 or SB525334, inhibitors of the TGF-β/Smad signaling pathway. An approximately 2-fold increase in the virus binding to the studied trophoblasts was found. In the presence of the Smad inhibitors, virus replication was significantly suppressed. An enhancement in Tyro3 and AXL (receptors for ZIKV) expression induced by TGF-β1 was also noted. The results suggest that TGF-β1 promotes the virus infection via the Smad pathway. Further studies should be carried out to clarify the underlying mechanisms of these findings

Paget’s disease derived in situ from reserve cell hyperplasia, squamous metaplasia, and squamous cell carcinoma of the esophagogastric junction: a case report

Abstract Background Extramammary Paget’s disease (EMPD) of the esophagus is a rare tumor, with most cases originating from invasive adenocarcinoma of the esophagus. Pure esophageal Paget’s disease, in which no underlying invasive carcinoma component is present, is extremely rare. In this report, we describe a case of EMPD of the esophagogastric junction with no evidence of invasive carcinoma. Case presentation An 81-year-old Japanese woman with a 2-week history of abdominal distension presented to our hospital for assessment. Endoscopic examination revealed a mild elevated granular lesion, with a slightly depressed irregular mucosa, in the distal esophagus, with EMPD confirmed by biopsy. Thoracoscopic esophagectomy with lymph node dissection was performed, with Paget cells observed on microscopic examination in the lower part of the esophageal epithelium. Only a few Paget cells stained positively for PAS/Alcian blue. Immunohistochemically, negative staining for CK5 and p63 were identified in the Paget cells, with positive staining for CK7. Furthermore, an intraepithelial squamous cell carcinoma, with squamous metaplasia and reserve cell hyperplasia, was observed in the gastric mucosa of the esophagogastric junction, adjacent to the Paget cells. Conclusions EMPD of the esophagus is a rare disease. We report a case of EMPD that was probably derived from a gastric squamous cell carcinoma, with squamous cell metaplasia and reserve cell hyperplasia, in the esophagogastric junction, which, to our knowledge, is the first report of this type of EMPD in the clinical literature

Association of High LAT1 Expression with Poor Prognosis and Recurrence in Colorectal Cancer Patients Treated with Oxaliplatin-Based Adjuvant Chemotherapy

The mammalian target of rapamycin (mTOR) is often activated in several cancers. We focused on two mTOR regulatory mechanisms: oxaliplatin-induced mTOR signaling and L-type amino acid transporter 1 (LAT1)-induced mTOR activation. High LAT1 expression in several cancers is associated with mTOR activation and resistance to chemotherapy. However, the significance of LAT1 has not yet been elucidated in colorectal cancer (CRC) patients treated with post-operative adjuvant chemotherapy. Immunohistochemistry was conducted to examine the significance of membrane LAT1 expression in 98 CRC patients who received adjuvant chemotherapy, including oxaliplatin. In vitro analysis was performed using CRC cell lines to determine the effects of LAT1 suppression on proliferation, oxaliplatin sensitivity, and mTOR signaling. LAT1 expression was associated with cancer aggressiveness and poor prognosis in 98 CRC patients treated with adjuvant chemotherapy. We found that positive LAT1 expression correlated with shorter survival in 43 patients treated with the capecitabine-plus-oxaliplatin (CAPOX) regimen. LAT1 suppression in CRC cells inhibited the proliferation potency and oxaliplatin-induced activation of mTOR signaling, and improved oxaliplatin sensitivity. LAT1 evaluation before adjuvant treatment may therefore be a sensitive marker for oxaliplatin-based regimens. Moreover, LAT1 may be a promising target for patients with refractory CRC